Draft Regulatory Impact Analysis
Proposed Rulemaking to Establish Green-
house Gas Emissions Standards and Fuel
Efficiency Standards for Medium- and
Heavy-Duty Engines and Vehicles
&EPA
United States
Environmental Protection
Agency
*****
NHTSA
www, nhtsa. gov
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Draft Regulatory Impact Analysis
Proposed Rulemaking to Establish Green-
house Gas Emissions Standards and Fuel
Efficiency Standards for Medium- and
Heavy-Duty Engines and Vehicles
Office of Transportation and Air Quality
U.S. Environmental Protection Agency
and
National Highway Traffic Safety Administration
U.S. Department of Transportation
NOTICE
This technical report does not necessarily represent final EPA decisions or
positions. It is intended to present technical analysis of issues using data
that are currently available. The purpose in the release of such reports is to
facilitate the exchange of technical information and to inform the public of
technical developments.
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TABLE OF CONTENTS
EXECUTIVE SUMMARY
CHAPTER 1: INDUSTRY CHARACTERIZATION
1.1 Introduction 1-1
1.2 Heavy-Duty Truck Categories 1-6
1.3 Heavy-Duty Truck Segments 1-8
1.4 Operations 1-14
1.5 Tire Manufacturers 1-26
1.6 Current U. S. and International GHG Voluntary Actions and Regulations 1-30
1.7 Trailers 1-33
1.8 Hybrids 1-37
CHAPTER 2: TECHNOLOGIES, COST, AND EFFECTIVENESS
2.1 Overview of Technologies 2-1
2.2 Overview of Technology Cost Methodology 2-2
2.3 Heavy-Duty Pickup Truck and Van Technologies and Costs 2-10
2.4 Heavy-Duty Engines 2-19
2.5 Class 7/8 Day Cabs and Sleeper Cabs 2-33
2.6 Class 2b-8 Vocational Vehicles 2-62
2.7 Air Conditioning 2-73
2.8 Trailers and GHG Emission Reduction Opportunities 2-76
2.9 Other Fuel Consumption and GHG Reducing Strategies 2-81
2.10 Summary of Technology Costs Used in this Analysis 2-89
CHAPTERS: TEST PROCEDURES
3.1 Heavy-Duty Engine Test Procedure 3-1
3.2 Aerodynamic Assessment 3-5
3.3 Tire Rolling Resistance 3-20
3.4 Drive Cycle 3-22
3.5 Tare Weights and Payload 3-26
3.6 Heavy-Duty Chassis Test Procedure 3-29
3.7 Hybrid Powertrain Test Procedures 3-30
3.8 HD Pickup Truck and Van Chassis Test Procedure 3-41
CHAPTER 4: VEHICLE SIMULATION MODEL
4.1 Purpose and Scope 4-1
4.2 Model Code Description 4-2
4.3 Feasibility of Using a Model to Simulate Testing 4-4
4.4 EPA and NHTSA Vehicle Compliance Model 4-7
4.5 Application of Model for Certification 4-18
CHAPTER: 5 EMISSIONS IMPACTS
5.1 Executive Summary 5-1
5.2 Introduction 5-2
5.3 Program Analysis and Modeling Methods 5-4
5.4 Greenhouse Gas Emission Impacts 5-11
5.5 Non-Greenhouse Gas Emission Impacts 5-12
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CHAPTER 6: RESULTS OF PROPOSED AND ALTERNATIVE STANDARDS
6.1 What Are the Alternatives that the Agencies Considered? 6-1
6.2 How Do These Alternatives Compare in Overall GHG Emissions Reductions and Fuel
Efficiency and Cost? 6-14
CHAPTER 7: TRUCK COSTS AND COSTS PER TON OF GHG EMISSIONS REDUCED
7.1 Costs Associated with the Proposed Program 7-1
7.2 Cost per Ton of GHG Emissions Reduced 7-4
7.3 Impacts of Reduction in Fuel Consumption 7-6
7.4 Key Parameters Used in the Estimation of Costs and Fuel Savings 7-7
CHAPTER 8: HEALTH AND ENVIRONMENTAL IMPACTS
8.1 Health and Environmental Effects of Non-GHG Pollutants 8-1
8.2Air Quality Impacts of Non-GHG Pollutants 8-33
8.3 Quantified and Monetized Non-GHG Health and Environmental Impacts 8-38
8.4 Changes in Atmospheric CO2 Concentrations, Global Mean Temperature, Sea Level
Rise, and Ocean pH Associated with the Proposal's GHG Emissions Reductions 8-44
8.5 Monetized CO2 Impacts 8-52
CHAPTER 9. ECONOMIC AND SOCIAL IMPACTS
9.1 Framework for Benefits and Costs 9-1
9.2 Rebound Effect 9-2
9.3 Other Economic Impacts 9-12
9.4 The Effect of Safety Standards and Voluntary Safety Improvements on Vehicle Weight
9-17
9.5 Petroleum and energy security impacts 9-21
9.6 Summary of Benefits and Costs 9-32
CHAPTER 10. SMALL BUSINESS FLEXIBILITY ANALYSIS
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List of Acronyms
2008$ U.S. Dollars in calendar year 2008
ug Microgram
ug/m3 Microgram per Cubic Meter
um Micrometers
AC Alternating Current
ACES Advanced Collaborative Emission Study
APU Auxiliary Power Unit
AQCD Air Quality Criteria Document
ASPEN Assessment System for Population Exposure Nationwide
ATA American Trucking Association
ATPJ Alliance for Transportation Research Institute
avg Average
BAG Battery Air Conditioning
BenMAP Benefits Mapping and Analysis Program
bhp Brake Horsepower
bhp-hrs Brake Horsepower Hours
BTS Bureau of Transportation
BTU British Thermal Unit
CAA Clean Air Act
CAE Computer Aided Engineering
CAFE Corporate Average Fuel Economy
CARB California Air Resources Board
CCP Coupled Cam Phasing
Cd Coefficient of Drag
CDC Centers for Disease Control
CFD Computational Fluid Dynamics
CFR Code of Federal Regulations
CH4 Methane
CILCC Combined International Local and Commuter Cycle
CITT Chemical Industry Institute of Toxicology
CMAQ Community Multiscale Air Quality
CO Carbon Monoxide
CO2 Carbon Dioxide
COI Cost of Illness
COPD Chronic Obstructive Pulmonary Disease
Co V Coefficient of Variation
CRGNSA Columbia River Gorge National Scenic Area
CSI Cambridge Systematics Inc.
CVD Cardiovascular Disease
DE Diesel Exhaust
DEAC Cylinder Deactiviation
DEF Diesel Exhaust Fluid
DHHS U.S. Department of Health and Human Services
DOC Diesel Oxidation Catalyst
DOE Department of Energy
DOT Department of Transportation
DPF Diesel Paniculate Filter
DPM Diesel Paniculate Matter
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DR Discount Rate
DRIA Draft Regulatory Impact Analysis
EC Elemental Carbon
ED Emergency Department
EGR Exhaust Gas Recirculation
EIA Energy Information Administration (part of the U.S. Department of Energy)
EMS-HAP Emissions Modeling System for Hazardous Air Pollution
EO Executive Order
EPA Environmental Protection Agency
EPS Electric Power Steering
EPS Electrified Parking Spaces
ERG Eastern Research Group
EV Electric Vehicle
F Frequency
FHWA Federal Highway Administration
FIA Forest Inventory and Analysis
FOH Fuel Operated Heater
FR Federal Register
g Gram
g/ton-mile Grams emitted to move one ton (2000 pounds) of freight over one mile
gal Gallon
gal/1000 ton-
mile Gallons of fuel used to move one ton of payload (2,000 pounds) over 1000 miles
GDP Gross Domestic Product
GEOS Goddard Earth Observing System
GHG Greenhouse Gases
GIFT Geospatial Intermodal Freight Transportation
GUI Graphical User Interface
GVW Gross Vehicle Weight Rating
GWP Global Warming Potential
HAD Diesel Health Assessment Document
HC Hydrocarbon
HD Heavy-Duty
HDUDDS Heavy Duty Urban Dynamometer Driving Cycle
HEI Health Effects Institute
HES Health Effects Subcommittee
HEV Hybrid Electric Vehicle
HFET Highway Fuel Economy Dynamometer Procedure
hp Horsepower
hrs Hours
HSC High Speed Cruise Duty Cycle
HTUF Hybrid Truck User Forum
hz Hertz
IARC International Agency for Research on Cancer
ICCT International Council on Clean Transport
ICD International Classification of Diseases
ICF ICF International
IMPROVE Interagency Monitoring of Protected Visual Environments
IRIS Integrated Risk Information System
ISA Integrated Science Assessment
JAMA Journal of the American Medical Association
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k Thousand
kg Kilogram
km Kilometer
kW Kilowatt
L Liter
Ib Pound
LD Light-Duty
LSC Low Speed Cruise Duty Cycle
m2 Square Meters
m3 Cubic Meters
MD Medium-Duty
mg Milligram
mi mile
min Minute
MM Million
MOVES Motor Vehicle Emissions Simulator
mpg Miles per Gallon
mph Miles per Hour
MSAT Mobile Source Air Toxic
MY Model Year
N2O Nitrous Oxide
NA Not Applicable
NAAQS National Ambient Air Quality Standards
NAICS North American Industry Classification System
NAS National Academy of Sciences
NATA National Air Toxic Assessment
NCAR National Center for Atmospheric Research
NCI National Cancer Institute
NCLAN National Crop Loss Assessment Network
NEC Net Energy Change Tolerance
NEI National Emissions Inventory
NESCCAF Northeast States Center for a Clean Air Future
NESHAP National Emissions Standards for Hazardous Air Pollutants
NHTSA National Highway Traffic Safety Administration
NiMH Nickel Metal-Hydride
NIOSH National Institute of Occupational Safety and Health
NMHC Nonmethane Hydrocarbons
NMMAPS National Morbidity, Mortality, and Air Pollution Study
NO Nitrogen Oxide
NO2 Nitrogen Dioxide
NOAA National Oceanic and Atmospheric Administration
NOx Oxides of Nitrogen
NPRM Notice of Proposed Rulemaking
NPV Net Present Value
NRC National Research Council
NVH Noise Vibration and Harshness
O&M Operating and maintenance
O3 Ozone
OAQPS Office of Air Quality Planning and Standards
OC Organic Carbon
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OE Original Equipment
OEHHA Office of Environmental Health Hazard Assessment
OEM Original Equipment Manufacturer
OHV Overhead Valve
OMB Office of Management and Budget
ORD EPA's Office of Research and Development
OTAQ Office of Transportation and Air Quality
Pa Pascal
PAH Polycyclic Aromatic Hydrocarbons
PEMS Portable Emissions Monitoring System
PHEV Plug-in Hybrid Electric Vehicles
PM Particulate Matter
PM10 Coarse Paniculate Matter (diameter of 10 um or less)
PM2.5 Fine Paniculate Matter (diameter of 2.5 um or less)
POM Polycyclic Organic Matter
ppb Parts per Billion
ppm Parts per Million
psi Pounds per Square Inch
PTO Power Take Off
R&D Research and Development
RDM Resisting Bending Moment
RESS Rechargeable Energy Storage System
RfC Reference Concentration
RIA Regulatory Impact Analysis
rpm Revolutions per Minute
RRc Rolling Resistance Coefficient
SAB Science Advisory Board
SAB-HES Science Advisory Board - Health Effects Subcommittee
SAE Society of Automotive Engineers
SBA Small Business Administration
SBAR Small Business Advocacy Review
SBREFA Small Business Regulatory Enforcement Fairness Act
SCC Social Cost of Carbon
SCR Selective Catalyst Reduction
SER Small Entity Representation
SGDI Stoichiometric Gasoline Direct Injection
SIDI Spark Ignition Direct Injection
SO2 Sulfur Dioxide
SOC State of Charge
SOHC Single Overhead Cam
SOx Oxides of Sulfur
STB Surface Transportation Board
SUV Sport Utility Vehicle
SVOC Semi-Volatile Organic Compound
TIAX TIAX LLC
Ton-mile One ton (2000 pounds) of pay load over one mile
TRU Trailer Refrigeration Unit
TSD Technical Support Document
TSS Thermal Storage
U/DAF Upward and Downward Adjustment Factor
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UCT Urban Creep and Transient Duty Cycle
UFP Ultra Fine Particles
USDA United States Department of Agriculture
UV Ultraviolet
UV-b Ultraviolet-b
VTUS Vehicle Inventory Use Survey
VMT Vehicle Miles Travelled
VOC Volatile Organic Compound
VSL Value of Statistical Life
WT Variable Valve Timing
WTP Willingness-to-Pay
WTVC World Wide Transient Vehicle Cycle
WVU West Virginia University
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Executive Summary
The Environmental Protection Agency (EPA) and the National Highway Traffic Safety
Administration (NHTSA), on behalf of the Department of Transportation, are each proposing
rules to establish a comprehensive Heavy-Duty National Program that would reduce greenhouse
gas emissions and increase fuel efficiency for on-road heavy-duty vehicles, responding to the
President's directive on May 21, 2010, to take coordinated steps to produce a new generation of
clean vehicles. NHTSA's proposed fuel consumption standards and EPA's proposed carbon
dioxide (€62) emissions standards would be tailored to each of three regulatory categories of
heavy-duty vehicles: (1) Combination Tractors; (2) Heavy-duty Pickup Trucks and Vans; and
(3) Vocational Vehicles, as well as gasoline and diesel heavy-duty engines. EPA's proposed
hydrofluorocarbon emissions standards would apply to air conditioning systems in tractors,
pickup trucks, and vans, and EPA's proposed nitrous oxide (N2O) and methane (CH4) emissions
standards would apply to all heavy-duty engines, pickup trucks, and vans.
Table 1 presents the rule-related benefits, costs and net benefits in both present value
terms and in annualized terms. In both cases, the discounted values are based on an underlying
time varying stream of cost and benefit values that extend into the future (2012 through 2050).
The distribution of each monetized economic impact over time can be viewed in the RIA
Chapters that follow this summary.
Present values represent the total amount that a stream of monetized costs/benefits/net
benefits that occur over time are worth now (in year 2008 dollar terms for this analysis),
accounting for the time value of money by discounting future values using either a 3 or 7 percent
discount rate, per OMB Circular A-4 guidance. An annualized value takes the present value and
converts it into a constant stream of annual values through a given time period (2012 through
2050 in this analysis) and thus averages (in present value terms) the annual values. The present
value of the constant stream of annualized values equals the present value of the underlying time
varying stream of values. Comparing annualized costs to annualized benefits is equivalent to
comparing the present values of costs and benefits, except that annualized values are on a per-
year basis.
It is important to note that annualized values cannot simply be summed over time to
reflect total costs/benefits/net benefits; they must be discounted and summed. Additionally, the
annualized value can vary substantially from the time varying stream of cost/benefit/net benefit
values that occur in any given year (e.g., the stream of costs represented by $0.34B and $0.58B
in Table 1 below average $1.5B from 2014 through 2018 and are zero from 2019-2050).
Table 1 Estimated Lifetime and Annualized Discounted Costs, Benefits, and Net Benefits for 2014-2018
Model Year HD Vehicles assuming the $22/ton SCC Valuea'b (billions 2008 dollars)
LIFETIME PRESENT VALUED - 3% DISCOUNT RATE
Costs
$7.7
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Benefits
Net Benefits
$49
$41
Annualized value0'6 - 3% Discount Rate
Costs
Benefits
Net Benefits
$0.34
$2.1
$1.8
Lifetime Present value°'d - 7% Discount Rate
Costs
Benefits
Net Benefits
$7.7
$34
$27
Annualized value0'6 - 7% Discount Rate
Costs
Benefits
Net Benefits
$0.58
$2.6
$2.0
Notes:
" Although the agencies estimated the benefits associated with four different values of a one ton
CO2 reduction (SCC: $5, $22, $36, $66), for the purposes of this overview presentation of
estimated costs and benefits we are showing the benefits associated with the marginal value
deemed to be central by the interagency working group on this topic: $22 per ton of CO2, in 2008
dollars and 2010 emissions and fuel consumption. As noted in Section VIII.G, SCC increases
overtime.
* Note that net present value of reduced GHG emissions is calculated differently than other
benefits. The same discount rate used to discount the value of damages from future emissions
(SCC at 5, 3, and 2.5 percent) is used to calculate net present value of SCC for internal
consistency. Refer to Section VIII.G for more detail.
0 Discounted values presented in this table are based on an underlying series of cost and benefit
values that extend into the future (2012 through 2050). The distribution of each monetized
economic impact over time can be viewed in the RIA that accompanies this preamble.
d Present value is the total, aggregated amount that a series of monetized costs or benefits that
occur over time is worth now (in year 2008 dollar terms), discounting future values to the present.
e The annualized value is the constant annual value through a given time period (2012 through
2050 in this analysis) whose summed present value equals the present value from which it was
derived.
This Regulatory Impact Analysis (RIA) provides detailed supporting documentation to
the EPA and NHTSA joint proposal under each of their respective statutory authorities. Because
there are slightly different requirements and flexibilities in the two authorizing statutes, this RIA
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provides documentation for the primary joint proposed provisions as well as for provisions
specific to each agency.
The agencies request comment on the methods and assumptions used to estimate costs,
benefits, and technology cost-effectiveness for the main proposal and all of the alternatives. The
agencies also seek comment on whether finalizing a different alternative stringency level for
certain regulatory categories would be appropriate given agency estimates of costs and benefits.
This RIA is generally organized to provide overall background information,
methodologies, and data inputs, followed by results of the various technical and economic
analyses. A summary of each chapter of the RIA follows.
Chapter 1: Industry Characterization. In order to assess the impacts of greenhouse gas
(GHG) and fuel efficiency regulations upon the affected industries, it is important to understand
the nature of the industries impacted by the regulations. The heavy-duty vehicle industries
include the manufacturers of Class 2b through Class 8 trucks, engines, and some equipment.
This chapter provides market information for each of these affected industries, as well as the
variety of ownership patters, for background purposes. Vehicles in these classes range from over
8,500 pounds (Ibs) gross vehicle weight rating (GVWR) to upwards of 80,000 Ibs and can be
used in applications ranging from ambulances to vehicles that transport the fuel that powers
them. The heavy-duty segment is very diverse both in terms of its type of vehicles and vehicle
usage patterns. Unlike the light-duty segment whose primary mission tends to be transporting
passengers for personal travel, the heavy duty segment has many different missions. Some
pickup trucks may be used for personal transportation to and from work with an average annual
mileage of 15,000 miles. Class 7 and 8 combination tractors are primarily used for freight
transportation, can carry up to 50,000 pounds of payload, and can travel more than 150,000 miles
per year.
Chapter 2: Technology Packages, Cost and Effectiveness. This chapter presents
details of the vehicle and engine technology packages for reducing greenhouse gas emissions and
fuel consumption. These packages represent potential ways that the industry could meet the
proposed CC>2 and fuel consumption stringency levels, and they provide the basis for the
technology costs and effectiveness analyses.
Chapter 3: Test Procedures. Laboratory procedures to physically test engines, vehicles,
and components are a crucial aspect of the proposed heavy-duty vehicle GHG and fuel
consumption program. The proposed rulemaking would establish several new test procedures
for both engine and vehicle compliance. This chapter describes the development process for the
test procedures being proposed, including methodologies for assessing engine emission
performance, the effects of aerodynamics and tire rolling resistance, as well as procedures for
chassis dynamometer testing and their associated drive cycles.
Chapter 4: Vehicle Simulation Model. An important aspect of a regulatory program is
its ability to accurately estimate the potential environmental benefits of heavy-duty truck
technologies through testing and analysis. Most large truck manufacturers employ various
computer simulation methods to estimate truck efficiency. Each method has advantages and
disadvantages. This section will focus on the use of a type truck simulation modeling that the
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agencies have developed specifically for assessing tailpipe GHG emissions and fuel consumption
for purposes of this rulemaking. The agencies are proposing to use this newly-developed
simulation model - the "Greenhouse gas Emissions Model (GEM)" — as the primary tool to
certify vocational and combination tractor heavy-duty vehicles (Class 2b through Class 8 heavy-
duty vehicles that are not heavy-duty pickups or vans) and discuss the model in this chapter.
Chapter 5: Emissions Impacts. This proposal estimates anticipated impacts from the
proposed CO2 emission and fuel efficiency standards. The agencies quantify emissions from the
GHGs carbon dioxide (CO2), methane (CH/i), nitrous oxide (ISbO) and hydrofluorocarbons
(HFCs). In addition to reducing the emissions of greenhouse gases and fuel consumption, this
proposal would also influence the emissions of "criteria" air pollutants, including carbon
monoxide (CO), fine particulate matter (PM2.s) and sulfur dioxide (SOx) and the ozone
precursors hydrocarbons (VOC) and oxides of nitrogen (NOx); and several air toxics (including
benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and acrolein), as described further in
Chapters.
The agencies used EPA's Motor Vehicle Emission Simulator (MOVES2010) to estimate
downstream (tailpipe) emission impacts, and a spreadsheet model based on emission factors the
"GREET" model to estimate upstream (fuel production and distribution) emission changes
resulting from the decreased fuel. Based on these analyses, the agencies estimate that this
proposal would lead to 72 million metric tons (MMT) of CC>2 equivalent (CC^EQ) of annual
GHG reduction and 5.8 billion gallons of fuel savings in the year 2030, as discussed in more
detail in Chapter 5.
Chapter 6: Results of Proposed and Alternative Standards. The heavy-duty truck
segment is very complex. The sector consists of a diverse group of impacted parties, including
engine manufacturers, chassis manufacturers, truck manufacturers, trailer manufacturers, truck
fleet owners and the public. The agencies have largely designed this proposal to maximize the
environmental and fuel savings benefits of the program, taking into account the unique and
varied nature of the regulated industries. In developing this proposal, we considered a number of
alternatives that could have resulted in fewer or potentially greater GHG and fuel consumption
reductions than the program we are proposing. Chapter 6 section summarizes the alternatives we
considered.
Chapter 7: Truck Costs and Costs per Ton of GHG. In this chapter, the agencies
present our estimate of the costs associated with the proposed program. The presentation
summarizes the costs associated with new technology expected to be added to meet the proposed
GHG and fuel consumption standards, including hardware costs to comply with the air
conditioning (A/C) leakage program. The analysis discussed in Chapter 7 provides our best
estimates of incremental costs on a per truck basis and on an annual total basis.
Chapter 8: Environmental and Health Impacts. This chapter discusses the health effects
associated with non-GHG pollutants, specifically: paniculate matter, ozone, nitrogen oxides
(NOx), sulfur oxides (SOx), carbon monoxide and air toxics. These pollutants would not be
directly regulated by the standards, but the standards would affect emissions of these pollutants
and precursors. Reductions in these pollutants would be co-benefits of the final rulemaking (that
is, benefits in addition to the benefits of reduced GHGs).
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Chapter 9: Economic and Social Impacts. This chapter provides a description of the
net benefits of the proposed HD National Program. To reach these conclusions, the chapter
discusses each of the following aspects of the analyses of benefits:
Rebound Effect: The VMT rebound effect refers to the fraction of fuel savings expected
to result from an increase in fuel efficiency that is offset by additional vehicle use.
Energy Security Impacts: A reduction of U.S. petroleum imports reduces both financial
and strategic risks associated with a potential disruption in supply or a spike in cost of a
particular energy source. This reduction in risk is a measure of improved U.S. energy security.
Other Impacts: There are other impacts associated with the proposed GHG emissions
and fuel efficiency standards. Lower fuel consumption would, presumably, result in fewer trips
to the filling station to refuel and, thus, time saved. The increase in vehicle-miles driven due to a
positive rebound effect may also increase the societal costs associated with traffic congestion,
motor vehicle crashes, and noise. The agencies also discuss the impacts of safety standards and
voluntary safety improvements on vehicle weight.
Chapter 9 also presents a summary of the total costs, total benefits, and net benefits
expected under the proposal.
Chapter 10: Small Business Flexibility Analysis. This chapter describes the agencies'
analysis of the small business impacts due to the joint proposal.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
Chapter 1: Industry Characterization
1.1 Introduction
1.1.1 Overview
In order to assess the impacts of greenhouse gas (GHG) regulations upon the affected
industries, it is important to understand the nature of the industries impacted by the
regulations. These industries include the manufacturers of Class 2b through Class 8 trucks,
engines, and some equipment. This chapter provides market information for each of these
affected industries for background purposes. Vehicles in these classes range from over 8,500
pounds (Ibs) gross vehicle weight rating (GVWR) to upwards of 80,000 Ibs and can be used in
applications ranging from ambulances to vehicles that transport the fuel that powers them.
Figure 1-1 shows the difference in vehicle classes in terms of GVWR and the different
applications found in these classes.
Figure 1-1 Description and Weight Ratings of Vehicle Classes
Minivan Utility van
CLASS 1
6,000 lb& less
Bucket
Multi-purpose Full-size pickup
City delivery Large walk-in
CLASS 5
16,001 to 19,500 Ib
CLASS 2a
6,001 10 8,500 Ib
CLASS 2b
8500 10 10.000 Ib
Minivan
Beverage Single-axle van p, AOO R
Utility van H H I I I I I ITIff III I IHv 19,501 to 26,000 Ib
Step van
hull-size pickup
Walk-in Conventional van
CLASS 3
10,001 to 14,000 Ib
Refuse
Furniture
CLASS 7
26,001 to 33,000 Ib
City delivery Utility van
Full-size pickup
iiiijliiilii |
City transit bus
Medium conventional
Conventional van City delivery CLASS 4
14,001 to 16,OOOIb
Dump
Cement
CLASS 8
33,001 Ib & over
Large walk-in
Heavy conventional COE sleeper
Source: Commercial Carrier Journal http://www.ccimagazine.com
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Regulatory Impact Analysis
Heavy-duty trucks in this rulemaking are defined as on-highway vehicles with a
GVWR greater than 8,500 Ibs and are not defined as Medium-Duty Passenger Vehicles
(MDPV). The EPA and NHTS A jointly developed the Light-Duty Vehicle Greenhouse Gas
Emissions Standards and Corporate Average Fuel Economy Standards; Final Rule 75 FR
25323 (May 7, 2010) which sets standards for Light Duty Vehicles, Light-Duty Trucks, and
Medium-Duty Passenger Vehicles (EPA-420-F-10-014). Light-duty trucks are vehicles with
GVWR less than 8,500 Ibs. MDPV are vehicles with GVWR less than 10,000 pounds which
meet the criteria outlined in 40 C.F.R. §86.1803-01. This grouping typically includes large
sport utility vehicles, small trucks, and mini-vans.
The heavy-duty segment is very diverse both in terms of its type of vehicles and
vehicle usage patterns. Unlike the light-duty segment whose primary mission tends to be
transporting passengers for personal travel, the heavy duty segment has many different
missions. Some pickup trucks may be used for personal transportation to and from work with
an average annual mileage of 15,000 miles. Class 7 and 8 combination tractors are primarily
used for freight transportation, can carry up to 50,000 pounds of payload, and can travel more
than 150,000 miles per year. For the purposes of this report, heavy-duty segment has been
separated as follows: Class 2b and 3 pickup trucks and vans (also referred to as FID pickup
trucks and vans), Class 2b through 8 vocational vehicles, Class 7 and 8 combination tractors,
trailers, and transit buses.
1.1.2 Freight Moved by Heavy-Duty Trucks
In 2008, heavy-duty trucks carried more freight in terms of tonnage and value in the
U.S. than all other modes of freight transportation combined, and are expected to move freight
at an even greater rate in the future.l According to the U.S. Department of Transportation
(DOT), the U.S. transportation system moved, on average an estimated 59 million tons of
goods worth an estimated $55 billion (in U.S. $2008) per day in 2008, or over 21 billion tons
of freight worth more than $20 trillion in the year 2008.2 Of this, trucks moved over 13
billion tons of freight worth an estimated $13 trillion in 2008, or an average of nearly 36
million tons of freight worth $37 billion a day. The DOT's Freight Analysis Framework
estimates that this tonnage will increase nearly 73 percent by 2035, and that the value of the
freight moved is increasing faster than the tons transported. Figure 1-2 shows the total tons of
freight moved by each mode of freight transportation in 2002, 2008 and projections for 2035.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
Figure 1-2 Total Weight of Shipments by Transportation Mode (millions of tons)
2035
12008
12002
Notes: [a] Intermodal includes U.S. Postal Service and courier shipments and all intermodal combinations,
except air and truck. Intermodal also includes oceangoing exports and imports that move between ports and
interior domestic locations by modes other than water.
[b] Pipeline also includes unknown shipments as data on region-to-region flows by pipeline are statistically
uncertain.
Source: U.S. DOT, Federal Highway Administration, "Freight Facts and Figures
1.1.3 Greenhouse Gas Emissions from Heavy-Duty Vehicles
The importance of this proposed rulemaking is highlighted by the fact that heavy-duty
trucks are the largest source of GHG emissions in the transportation sector after light-duty
vehicles. This sector represents approximately 22 percent of all transportation related GHG
emissions as shown in Figure 1-3. Heavy-duty trucks are also a fast growing source of GHG
emissions; total GHG emissions from this sector increased over 72 percent from 1990-2008
while GHG emissions from passenger cars grew approximately 20 percent over the same
period.3 Available technologies developed through EPA's SmartWay program and through
DOE's 21st Century Truck Partnership can achieve reductions from 10-20 percent and are
applicable to the majority of heavy-duty vehicles; examples of these technologies include
aerodynamic bumpers, mirrors, and fairings.4
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Regulatory Impact Analysis
Figure 1-3 Transportation Related Greenhouse Gas Emissions (Tg CO2 Eq.) in 2008
i Cars and Light Duty Trucks
i Medium/Heavy Duty Trucks and Buses
i Aircraft
i Rail
i Ships and Boats
I Pipeline
Other (Motorcycles and Lubricants)
Source: U.S. EPA, Inventory of Greenhouse Gas Emissions and Sinks: 1990-2008, published April, 2010
1.1.4 Fuel Economy of Heavy-Duty Vehicles
While there is a corporate average fuel economy (CAFE) program for light-duty
trucks and vehicles, the nature of the commercial truck market can present complications to
such a structure in particular due to the production process, diversity of products, and usage
patterns.5 For example, in the light-duty market a manufacturer builds a complete vehicle
and therefore, is responsible to certify that vehicle. In the heavy-duty truck market, there may
be separate: chassis, engine, body and equipment manufacturers that contribute to the build
process of a single truck; in addition, there are no companies that produce trucks and trailers
and a given tractor may pull hundreds of different trailer types over the course of its life.
Further, fuel economy is highly dependent on the configuration of a truck, for example: the
type of body or box, engine, axle/gear ratios, cab, or other equipment installed on the vehicle;
whether or not a truck carries cargo or has a specialized function (e.g. a bucket truck). Due to
the varying needs of the industry, many of these trucks are custom built resulting in literally
thousands of different truck configuration. Finally, usage patterns and duty cycles also
greatly affect fuel economy, for example how trucks are loaded (cubed or weighed out) and
how they are driven (delivery trucks travel at lower speeds and make frequent stops compared
to a line-haul combination tractor). The potential to reduce fuel consumption, therefore, is
also highly dependent on the truck configuration and usage.
1-4
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
The agencies recognize that while historic fuel economy and GHG emissions on a
mile per gallon basis from heavy-duty trucks has been largely flat for more than 30 years, we
cannot conclude with certainty that future improvements absent regulation would not occur.A
Programs like EPA's SmartWay program are not only helping the industry improve logistics
and operations, but are also helping to encourage greater use of truck efficiency technologies.
Looking at the total fuel consumed, total miles traveled, and total tons shipped in the U.S. or
the average payload specific fuel consumption for the entire heavy-duty fleet from 1975
through 2005, the amount of fuel required to move a given amount of freight a given distance
has been reduced by more than half as a result of improvements in technology, as shown in
Figure 1-4.5
Figure 1-4 U.S. Average Payload-Specific Fuel Consumption of the Heavy-Duty Fleet
0)
a
•o
re
c
O
*
CL
0.045 -,
Ofidn -
Ort-^E „
OA-i ft
n An ft -
^^^_^^
^^"^^*s.
^\
^^>^^^
__^^
1980
1985
1990
1S95
2000
(Source: NAS, Technologies and Approaches to Reducing Fuel Consumption of Medium- and Heavy-
Duty Vehicles available here: http://www.nap.edu/openbook.php?record_id=12845&page=Rl)
Currently, manufacturers of vehicles with a GVW of over 8,500 pounds are not
required to test and report fuel economy values, however, fuel economy ranges as of 2007 by
vehicle class are presented in a study completed by the National Academy of Sciences (NAS),
the U.S. Department of Transportation (DOT), and the National Highway Traffic Safety
Administration (NHTSA). As one would expect, the larger the truck class the lower the fuel
economy, for example, a typical mile per gallon (mpg) estimate for Class 2b vehicle is 10-15
mpg where a typical Class 8 combination tractor is estimated to get 4-7.5 mpg, as shown in
Table 1-1.
A Over the last 30 years the average annual improvement in fuel economy has been 0.09%. See U. S.
Department of Transportation, Federal Highway Administration, Highway Statistics 2008, Washington, DC,
2009, Table VM1 averaging annual performance for the years from 1979-2008.
1-5
-------
Regulatory Impact Analysis
Table 1-1 Estimated Fuel Economy by Truck Class
CLASS
2b
3
4
5
6
7
8 Combination
Trucks
8 Other
EXAMPLE
PRODUCTION
VEHICLE
Dodge Ram 2500
Pickup Truck
Chevrolet Silverado
3500 Pickup Truck
Ford F-450
KenworthT170
Peterbilt Model 330
Kenworth T370
International Lone Star
Mack Granite GU814
GVW
8,501-10,000
10,001-14,000
14,001-16,000
16,001-19,500
19,501-26,000
26,001-33,000
33,001-80,000
33,001-80,000
TYPICAL
MPG RANGE
IN 2007
10-15
8-13
7-12
6-12
5-12
4-8
4-7.5
2.5-6
TYPICAL
TON-
MPG
26
30
42
39
49
55
155
115
ANNUAL FUEL
CONSUMPTION RANGE
(THOUSANDS OF
GALLONS)
1.5-2.7
2.5-3.8
2.9-5.0
3.3-5.0
5.0-7.0
6.0-8.0
19-27
10- 13
1.2 Heavy-Duty Truck Categories
This program addresses vehicles that fall into the following four categories:
HD pickups and vans (typically Class 2b and 3), Vocational vehicles (typically Class
2b-8), Tractors (typically Class 7 and 8), and Heavy-Duty engines.6 Class 2b and 3
pickups and vans are used for commercial purposes such as ambulances, shuttle buses,
etc. The U.S. Energy Information Administration (EIA) estimates that Class 2b
vehicles get approximately 14.5 - 15.6 miles per gallon (mpg) in 2010.6 Class 2b-8
vocational vehicles encompass a wide range of heavy-duty vehicles such as delivery
trucks, school buses, etc. Fuel economy estimates for Class 3-6 are 7.8 mpg in 2010.7
Class 8 combinations tractors operate as either short-haul or long-haul trucks.
Combination tractors that operate as short-haul trucks also known as day cabs, are
tractor trailers that do not have sleeping quarters for the driver and haul trailers only
short distances, typically into metropolitan areas. Combination tractors that operate as
long-haul trucks are those equipped with sleeping quarters for the driver, and tend to
drive well over 1,000 miles per trip; this category contributed the most GHG
emissions of these four categories at just over 38 percent of the total CO 2 emissions in
2005 as shown in Figure 1-5. The EIA estimates that in 2010, Class 8 freight hauling
trucks get slightly over 6 mpg.
B For purposes of this document, the term "heavy-duty" or "HD" is used to apply to all highway vehicles and
engines that are not within the range of light-duty vehicles, light-duty trucks, and medium-duty passenger
vehicles (MDPV) covered by the GHG and Corporate Average Fuel Economy (CAFE) standards issued for
model years (MY) 2012-2016. Unless specified otherwise, the heavy-duty category incorporates all vehicles
rated at a gross vehicle weight of 8,500 pounds, and the engines that power them, except for MDPVs.
1-6
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
Figure 1-5 Tons of CO2 Emitted from Heavy-Duty Trucking in 2005
2005 tons CO-
15.3%
26.8%
19.7%
I Vocational
i 2b3 Pickups/Vans
Comb. Long-haul
i Comb. Short-haul
38.3%
1.2.1 Heavy-Duty Vehicles Sales
Although not first in terms of GHG emissions, Class 2b and 3 pickup trucks and vans
are first in terms of sales volumes, with sales of over 1.3 million units in 2005, or nearly 66
percent of the heavy-duty market. Sales of Class 3-8 vocational vehicles are the second most
numerous, selling over one-half million units in 2005, or nearly 25 percent of the heavy-duty
market. Since 2005, sales of all heavy-duty trucks have decreased as the economy contracted;
the U.S. EPA's MOVES model based on proprietary sales projections combined with the U.S.
Energy Information Administration's Annual Energy Outlook reflects a slow recovery in
sales. Figure 1-6 and Figure 1-7 show the sales volumes for 2005 and projected sales for
2014 respectively, reflecting the market slowdown and recovery, while Table 1-2 shows sales
projections by market segment for 2014-2018.
Table 1-2 Sales Projection by Market Segment 2014-2018
SALES
ESTIMATES
2014
2015
2016
2017
2018
2B/3
PICKUPS/VANS
785,000
730,000
713,000
708,000
717,000
VOCATIONAL
VEHICLES
555,000
573,000
592,000
611,000
630,000
COMBINATION
SHORT HAUL
50,000
50,000
51,000
52,000
53,000
COMBINATION
LONG HAUL
73,000
74,000
75,000
77,000
78,000
TOTAL
1,460,000
1,430,000
1,430,000
1,450,000
1,480,000
1-7
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Regulatory Impact Analysis
Figure 1-6 2005 Heavy-Duty Truck Sales by Category
2005: Sales by Category
117,000
I Vocational
12b3 Pickups/Vans
iComb. Long-haul
I Comb. Short-haul
Figure 1-7 Projected Truck Sales for 2014 by Category
2014: Sales Projections by Category
72,600
• Vocational
• 2b3 Pickups/Vans
= Comb. Long-haul
• Comb. Short-haul
1.3 Heavy-Duty Truck Segments
1.3.1 Heavy-Duty Pickup Trucks and Vans
Class 2b and 3 pickup trucks and vans rank highest in terms of sales volumes, but
together make up the third largest sector contributing to the heavy-duty truck GHG emissions
(Class 2b through Class 8). There are number of reasons to explain this difference, but
mainly it is the vehicle usage patterns and engine size. Class 2b/3 consists of pickup trucks
and vans with a GVW between 8,500 and 14,000 pounds. Class 2b/3 truck manufacturers are
predominately GM, Ford, and Chrysler, with Isuzu, Daimler, Mitsubishi FUSO, and Nissan
1-S
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
also offering vehicles in this market segment. Figure 1-8 shows two examples of this
category, a GM Chevrolet Express G3500 and a Dodge Ram 3500HD.
Figure 1-8 Examples of Class 2b and 3 Pickup Trucks and Vans
Source: http: wT.\v,-.tiuckpaper.com
S ourc e: http: vvwiv. auto fani.us image s
Class 2b/3 vehicles are sold either as complete or incomplete vehicles. For example a
'complete vehicle' can be a chassis cab (engine, chassis, wheels, and cab) or a rolling chassis
(engine, chassis and wheels), while an 'incomplete chassis' could be sold as an engine and
chassis only - no wheels. The technologies that can be used to reduce GHG emissions from
this segment are very similar to the ones used for lighter pickup trucks and vans (Class 2a),
which are part of the Light Duty GHG program. These technologies include engine
improvements such as friction reduction, cylinder deactivation, cam phasing, and gasoline
direct injection; aerodynamic improvements; low rolling resistance tires; and transmission
improvements. The Class 2b/3 gasoline trucks and vans are currently certified with chassis
dynamometer testing. The Class 2b/3 diesel trucks have an option to certify using the chassis
dynamometer test procedure.
1.3.2 Vocational Vehicles
This market segment includes a wide range of heavy-duty vehicles ranging from 8,501
pounds to greater than 33,000 pounds GVW. In 2005, sales of these vehicles were the second
most numerous sold in the heavy-duty truck market, with over 500,000 units sold, making up
nearly one-quarter of all heavy-duty truck sales. The vocational vehicle segment was also
responsible for emitting 15.3 percent of the GHG emissions in 2005 from the total heavy-duty
truck market. A majority of these vehicles are powered by diesel engines; primary examples
of this truck type include delivery trucks, dump trucks, cement trucks, buses, cranes, etc.
Figure 1-9 shows two examples of this vehicle category including a United Parcel Service
(UPS) delivery truck, and a Ford F750 Bucket Truck.
1-9
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Regulatory Impact Analysis
Figure 1-9 Examples of Class 3-8 Vocation Truck Applications
www.versalifteast.com/Rent-Bucket-Trucks.htm
www.seedmagazine.com/images/uploads/upstr
Class 2b - 8 vocational vehicles are typically sold as an incomplete chassis with
multiple "outfitters" for example, an engine manufacturer, a body manufacturer, and an
equipment manufacturer (e.g. a crane manufacturer). Manufacturers of vehicles within this
segment vary widely and shift with class, as Figure 1-10 highlights. Vocational vehicles
manufacturers include: GM, Ford, Chrysler, Isuzu, Mitsubishi, Volvo, Daimler, International,
and PACCAR, while engine manufacturers include: Cummins, GM, Navistar, Hino, Isuzu,
Volvo, Detroit Diesel, and PACCAR. Manufacturers of vocational vehicle bodies are
numerous, according to the 2002 Census, there were 759 companies classified under the
North American Industry Classification System (NAICS) 336211, "Motor Vehicle Body
Manufacturers," examples of these companies include: Utilimaster and Heller Truck Body
Corp.
Opportunities for GHG reductions can include both engine and vehicle
improvements. Currently, there are a limited number of available Class 2b-8 vocational
vehicles produced in a hybrid configuration. International (owned by Navistar) makes the
DuraStar™ Hybrid and claims that this option offers a 30 to 40 percent fuel economy benefit
over standard in-city pickup and delivery applications, and offers a more than a 60 percent
increase in fuel economy in utility-type applications where the vehicle can be shut off while
o
electric power still operates the vehicle.
1-10
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
Figure 1-10 Class 3-8 Vocational Vehicle Manufacturer Shift with Class
iFreightliner •International HMack nPeterbuilt nKenworth nVolvo
i Ford BGMC n Chevrolet nlsuzu n Dodge n Mitsubishi
Class 3
Class 4
Class 6
Box/Freight
Class 8
Box/Freight
Class 8 Class 8 Class 8
Refuse Construction Tractor
Source: ICCT
1.3.3 Tractors
Class 7 and 8 trucks are the largest and most powerful trucks of the heavy duty vehicle
fleet. These trucks use almost two-thirds of all truck fuel, and are typically categorized into
two smaller segments - short-haul and long-haul. 9 Combination tractors operating as short-
haul trucks are tractor trailers typically used for routes less than 500 miles, and tend to travel
at lower average speeds than long-haul trucks. Short-haul combination tractors therefore, do
not include sleeping accommodations for the driver.
Long-haul combination tractors typically travel at least 1,000 miles along a trip route.
Long-haul operation occurs primarily on highways and accounts for 60 to 70 percent of the
fuel use in this class. The remaining 30 to 40 percent of fuel is used by other short-and
medium-haul regional applications. ° The most common trailer hauled by both short- and
long-haul combination tractors is a 53-foot dry box van trailer, which accounts for nearly 60
to 70 percent of heavy-duty Class 8 on-road mileage. Leading U.S. manufacturers of Class 8
trucks include companies such as International, Freightliner, Peterbilt, PACCAR, Kenworth,
Mack, Volvo, and Western Star; while common engine manufacturers include companies
such as Cummins, Navistar, and Detroit Diesel. Figure 1-11 shows example Class 8 day cab
and sleeper cab combination tractors. The price of a new Class 8 vehicle can range from
$90,000 to well over $110,000 for fully equipped models.11
1-11
-------
Regulatory Impact Analysis
Figure 1-11 Example Day Cab and Sleeper Cab Tractors
rmm
Source: www.internationaltracks.com/Tracks/Tracks/Series/LoneStar Source: www.freightlijnertracks.com/media/pdtfcoronadojwochure.pdf
1.3.4 Buses
Buses generally fall into either Class 6 or Class 7 categories and can come in many
forms, including: transit buses, large school buses, small school buses, and motorcoaches.
Typically, most bus manufacturers assemble the entire chassis from systems manufactured by
a variety of suppliers, while their engines are commonly manufactured by companies such as
Detroit Diesel, and Navistar.12 Typically, transit buses have about a 12 year lifespan, and
approximately 5000-5500 units a year enter the fleet, where school buses can last upwards of
fifteen years or longer as school buses are not eligible for Federal Transit Administration
funding as most transit buses are.13 Currently, about 32 percent of U.S. buses have an
alternative energy source and are powered by a source other than diesel or gas. According to
the American Public Transportation Association's (APTA) "2008 Public Transportation Fact
Book," in 2007, 22 percent of approximately 80,000 transit buses operated on alternative
power, primarily compressed or liquefied natural gas (as well as recent interest in and growth
of hybrid electric buses). Additionally, according to the Union of Concerned Scientists'
"School Bus Pollution Report Card 2006 Grading the Schools" (May, 2006), less than 1
percent (4,145) of the approximately 505,000 school buses in the U.S. run on LNG/CNG; less
than 2 percent (8,632) run on biodiesel, mostly B20. There are several types of bus fleets
operating on alternative power. For example, CNG (Los Angeles Metropolitan Transit
Authority) has the largest operational fleet, HEV (GM-Allison Transmission, BAE Systems,
ISE Corporation, and Ebus (22' shuttles)) manufacture hybrid buses, while New York City
Transit had a pilot program, and BEV (Proterra), Fuel Cell (fuel cell bus projects with New
Flyer, Van Hool, Gilig, Daimler (Orion), EBus).
In 2008, transit buses were responsible for moving 53 percent of all unlinked
passenger mass-transit trips which is just over 5.5 billion passenger trips.14 In addition,
APTA reports that in terms of passenger miles by mode, busing is also responsible for the
1-12
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
largest share (over 39 percent) of passenger transportation, at nearly 22 billion passenger
miles. Although the number of buses manufactured in the U.S. is less than 5,500 per year, the
number of manufacturing facilities involved in producing these buses is spread throughout the
U.S., as shown in Figure 1-12.15 While transit buses are typically used for two full shifts
nearly every day and can average up to 30,000 miles per year of usage, school buses are used
only twice a day and only on days when school is in session and typically accumulate just
over 11,000 miles per year. School buses transport over 25 million children each year with a
fleet of buses that is 94 percent diesel engine powered.
Figure 1-12 Selected U.S. Manufacturing Locations for Transit Buses and Components
n
(_ ^'4 '. I'-'
'~*&>m '• AZ
}tK3&rt**&
|P- -VTN cT r-S
? o i-rrs^
• Chassis, Body/Interior, Eleclrlc/Eleclronlc Systems'
O Aflermarkat RemsnufacHirtng & Cleaning Systems Note: Selected locations only; not exhaustive.
O OEMs
Source: Center on Globalization, Governance & Competitiveness, 2009
Compared to other modes of mass transit, and even other types of heavy-duty truck
operations, buses travel generally operates at the lowest speed and tends to stop much more
frequently than other HD vehicles. Figure 1-13 shows a comparison of average operational
speed and length of trip for different modes of mass transit. Buses also make up one of the
largest fleets of vehicles within the FID sector, having over 66,000 buses available for service
in 2008. At the beginning of 2009 they were approximately 7.5 years old with 5.5 percent
having been rehabilitated during their lifetime.
1-13
-------
Regulatory Impact Analysis
•-'
V
<
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
0.0
Figure 1-13 Vehicle Speed vs. Trip Length by Mode in 2008
Commuter Rail
Heavy Rail
Light Rail
Paratransit
Trolleybus
5.0 10.0 15.0 20.0
Average Unlinked Trip Length (Miles)
Source: 2009 APIA Fact Book
25.0
1.4 Operations
1.4.1 Trucking as a Mode of Freight Transportation
Trucks travel over a considerably larger domain than trains do, for example, in 2007
there were over 4 million miles of public roads compared to 140,000 miles of track.16 In 2007
there were over 2 million combination tractors registered in the U.S, and over 5.5 million
trailers (including all commercial type vehicles and semitrailers that are in private or for hire
use).1? Table 1-3 presents the number of trucks compared to the number of vessels and other
modes of transportation that move freight.
1-14
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
Table 1-3 Number of U.S. Vehicles, Vessels, and Other Conveyances: 1980-2007
1980
161J490.159
4,373,784
1,416,869
5,790,653
3.6
28,094
1,168,114
102,161
440,552
38,788
31,662
7,126
864
:4 3.5
1990
193,057,376
4,486,981
1,708,895
6,195,876
3.2
18,835
658,902
103,527
449,832
39,445
31,209
8,238
636
_____17_
2000
225321,241
5,926,030
2,096,619
8,022,649
3.6
20,028
560,1 54
132,448
688,194
41,354
33,1 52
8,202
454
1.6
2007
254,403,081
6,806,630
2,220,995
9,027,625
3.5
24,143
460,172
120,463
805,074
40,695
31,654
9,041
216
0.7
Highway
Truck, single-unit 2-axle 6-tire or more
Truck, combination
Truck, total
Trucks as percent of all highway vehicles
Rail
Class I, locomotive
Class I, freight cars'
Nonclass I, freight cars1
Car companies and shippers freight cars
Water
Nonself-propelled vessels2
Self-propelled vessels3
Oceangoing steam and motor ships4
U.S. Flag fleet as percent of world fleet4
'Beginning with 2001 data, Canadian-owned U.S. railroads are excluded. Canadian-owned U.S. railroads
accounted for approximately 176,275 In 2009,
-'Nonself-propelled Include dry-cargo and railroad-car floats.
-'Seif-propeited vessels dry cargo, passenger, off-shore support, tankers, towboats.
•'1,000 gross tons and over.
Source: The Federal Highway Administration "Freight Facts and Figures 2009."
Trucks move more than one-half of all hazardous materials within the U.S.; however,
truck ton miles of hazardous shipments account for only about one-third of all transportation
ton-miles due to the relatively short distances these materials are typically carried. In terms of
growing international trade, trucks are the most common mode used to move imports and
exports between both borders and inland locations. Table 1-5 shows the tons and value
moved by truck compared to other transportation methods.
Table 1-4 Domestic Mode of Exports and Imports by Tonnage and Value in 2002 and Projections for
2035.
32
Truck3
Rail
Water
Air, air and truckb
IntermodaT
Pipeline and
unknown"1
MILLIONS OF
TONS
2002
797
200
106
9
22
524
2035
2116
397
168
54
50
760
BILLIONS OF
DOLLARS (U.S.
$2002)
2002
1198
114
26
614
52
141
2035
6193
275
49
5242
281
238
Notes: a Excludes truck moves to and from airports.
b Includes truck moves to and from airports.
0 Intermodal includes U.S. Postal Service and courier shipments and all intermodal combinations, except air and
truck. In this table, oceangoing exports and imports that move between ports and domestic locations by single
modes are classified by the domestic mode rather than the intermodal.
d Pipeline and unknown shipments are combined because data on region-to-region flows by pipeline are statistically
uncertain.
1-15
-------
Regulatory Impact Analysis
Conversely, transportation of foreign trade is dominated by movement via water with
trucks hauling approximately 16 percent of imported freight followed by rail and pipeline.18
As of 2009, Canada was the top trading partner with the United States in terms of the value of
the merchandise traded ($430 billion in U.S. $2009), second was China ($366 billion in U.S.
$2009), and third was Mexico ($305 billion in U.S. $2008).19 Truck traffic dominates
transportation modes from the two North American trade partners. As of 2009, over 58
percent of total imported and exported freight moved between the U.S. and Canada was
hauled by truck between Canada and the U.S., while over 68 percent of total imported and
exported freight moved between the U.S. and Mexico was hauled by truck between Mexico
and the U.S, as shown in Figure 1-14.20
Figure 1-14 North American Transborder Freight
North American Transborder Freight
Data for 2009
I Canada • Mexico
Source: Bureau of Transportation Statistics: North American Transborder Freight Data
The number of truck configurations is only limited by technical compatibility and
customer demand; order lead times can vary from a few months to a year when demand is
high. Truck purchasers (individual owner-operators and fleets) custom order their trucks to
meet very specific needs, e.g. fleets in Kansas choose high gear ratios for good fuel economy
on flat roads, fleets in the Rocky Mountains choose lower gear ratios to allow adequate
performance in the mountains, etc.
1.4.2 Operational Costs
One of the largest components of truck operational costs can be fuel costs, although
this is dependent on the price of fuel, and can be as much as $70,000 - $125,000 annually per
truck. High fuel price is a key driver for adopting new technologies as the lifetime fuel cost to
operate a Class 8 truck is nearly five times that of the original price of the truck, compared to
about a one-to-one ratio for passenger vehicle. HD truck fleets typically operate on a very
thin profit margin (1-2 percent); therefore, increased truck fuel economy can greatly increase
a company's profitability.31 New technologies are generally introduced on Class 8 vehicles
first, and then are quickly implemented into other truck class segments due to the similarity of
these vehicles.
1-16
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
1.4.3 Operators
There are nearly nine million people in trucking related jobs, with 15 percent involved
in manufacturing of the vehicles and trailers, and the majority of over three million, working
as truck drivers. Many drivers are not part of large fleets, but are independent owner-
operators where the driver independently owns his or her vehicle, leaving 87 percent of
trucking fleets operating less than 6 percent of all trucks.
The U.S. Department of Transportation's Federal Motor Carrier Safety Administration
has developed Hours-of-Service regulations that limit when and how long commercial motor
vehicle drivers may drive (Table 1-5 summarizes these rules). In general, drivers must take a
ten consecutive hour rest / break per 24 hour day, and they may not drive for more than a
week without taking a 34 consecutive hour break. These regulations have increased the
importance of idle reduction technologies, as drivers can have a significant amount of
downtime during a trip in order to comply with these mandates. During their required off-
duty hours, drivers face additional regulations they must abide by if they rest in their truck
and idle the main engine to provide cab comfort. Currently, regulations that prohibit trucks
from idling can differ from state to state, county to county, and city to city. The American
Transportation Research Institute has compiled a list of nearly 45 different regulations that
exist in different locals with fines for non-compliance ranging from $50 to $25,000 and can
include up to two years in prison.
The need for auxiliary cab heating, cooling, and sources of electricity such as those
provided by idle reduction devices such as auxiliary power units, is highlighted by the fact
that driver comfort is not typically included as an exemption to allow idling, nor are, in some
cases, the idling of trailer refrigeration units that require power to keep freight at a controlled
temperature.
Table 1-5 Summary of Hours of Service Rules
PROPERTY-CARRYING CMV DRIVERS
11-Hour Driving Limit
May drive a maximum of 1 1 hours after 10 consecutive hours
off duty.
14-Hour Limit
May not drive beyond the 14th consecutive hour after coming
on duty, following 10 consecutive hours off duty. Off-duty
time does not extend the 14-hour period.
60/70-Hour On-Duty Limit
May not drive after 60/70 hours on duty in 7/8 consecutive
days. A driver may restart a 7/8 consecutive day period after
taking 34 or more consecutive hours off duty.
Sleeper Berth Provision
Drivers using the sleeper berth provision must take at least 8
consecutive hours in the sleeper berth, plus a separate 2
consecutive hours either in the sleeper berth, off duty, or any
combination of the two.
PASSENGER-CARRYING CMV DRIVERS
10-Hour Driving Limit
May drive a maximum of 10 hours after 8 consecutive hours off
duty.
15-Hour On-Duty Limit
May not drive after having been on duty for 15 hours, following 8
consecutive hours off duty. Off-duty time is not included in the 15-
hour period.
60/70-Hour On-Duty Limit
May not drive after 60/70 hours on duty in 7/8 consecutive days.
Sleeper Berth Provision
Drivers using a sleeper berth must take at least 8 hours in the
sleeper berth, and may split the sleeper-berth time into two periods
provided neither is less than 2 hours.
Source: Federal Motor Carrier Safety Administration
1-17
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Regulatory Impact Analysis
1.4.4 Heavy-Duty Truck Operating Speeds
In addition to the federal operating regulations, drivers must be aware of the variety of
speed limits along their route, as these can vary both interstate and intrastate. 21'22 Currently,
eight states have different speed limits for cars than they do for trucks, one state has different
truck speed limits for night and day, and one state has a different speed limit for hazmat
haulers than other trucks. In all, there are thirteen different car and truck speed combinations
in the U.S. today; Table 1-6 shows the different combination of vehicle and truck speed
limits, as well as the different speed limits by location.
Table 1-6 U.S. Truck and Vehicle Speed Limits
SPEED LIMIT
Trucks 75 / Autos 75
Trucks 70 / Autos 70
Trucks 65 / Autos 65
Trucks 60 / Autos 60
Trucks 55 / Autos 55
Trucks 65 / Autos 75
Trucks 65 / Autos 70
Trucks 60 / Autos 70
Trucks 55 / Autos 70
Trucks 55 / Autos 65
Trucks 65
(on the Turnpike Only)
Trucks and Autos 70
(65 at night)
Hazmat Trucks 55mph
STATES WITH THE SAME SPEED LIMIT
Arizona, Colorado, Nebraska, Nevada, New Mexico, North Dakota, Oklahoma, South
Dakota, Utah0, Wyoming
Alabama, Florida, Georgia, Iowa, Kansas, Louisiana, Minnesota, Mississippi,
Missouri, North Carolina, South Carolina, Tennessee, West Virginia,
Alaska, Connecticut, Delaware, Illinois, Kentucky3, Maine, Maryland, Massachusetts,
New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island,
Vermont, Virginia"1, Wisconsin
Hawaii
District of Columbia
Montana, Idaho
Arkansas, Indiana
Washington, Michigan
California
Oregon
Ohio
Texasb
Alabama
Notes: [a] Effective as of July 10, 2007, the posted speed limit is 70 mph in designated areas on 1-75 and 1-71.
[b] In sections of 1-10 and 1-20 in rural West Texas, the speed limit for passenger cars and light trucks is 80 mph. For large trucks, the speed
limit is 70 mph in the daytime and 65 mph at night. For cars, it is also 65 mph at night.
[c] Based on 2008 Utah House Bill 406, which became effective on May 5, 2008, portions of 1-15 have a posted limit of 80 mph.
[d] Effective July 1, 2006, the posted speed limit on 1-85 maybe as high as 70 mph.
1.4.5 Trucking Roadways
The main function of the National Network is to support interstate commerce by
regulating the size of trucks. Its authority stems from the Surface Transportation Assistance
Act of 1982 (P.L. 97-424) which authorized the National Network to allow conventional
combinations on "the Interstate System and those portions of the Federal-aid Primary System
... serving to link principal cities and densely developed portions of the States ... [on] high
volume route[s] utilized extensively by large vehicles for interstate commerce ... [which do]
not have any unusual characteristics causing current or anticipated safety problems."23 The
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
National Network has not changed significantly since its inception and is only modified if
states petition to have segments outside of the current network added or deleted, Figure 1-15
shows the National Network of the U.S. c
Additionally, there is the National Highway System (NHS), which was created by the
National Highway System Designation Act of 1995 (P.L. 104-59). The main focus of the
NHS is to support interstate commerce by focusing on federal investments. Currently, there is
a portion of the NHS that is over 4,000 miles long which supports a minimum of 10,000
trucks per day and can have sections where at least every fourth vehicle is a truck. Both the
National Network and the NHS are approximately the same length, roughly 200,000 miles,
but the National Network includes approximately 65,000 miles of highways in addition to the
NHS, and the NHS includes about 50,000 miles of highways that are not in the National
Network.
c Tractors with one semitrailer up to 48 feet in length or with one 28-foot semitrailer and one 28-foot trailer, and
can be up to 102 inches wide. Single 53-foot trailers are allowed in 25 states without special permits and in an
additional 3 states subject to limits on distance of kingpin to rearmost axle.
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Regulatory Impact Analysis
Figure 1-15 The National Network for Conventional Combination Trucks
Interstate (National Network and National Highway System)
National Network on National Highway System
National Network Not on National Highway System
Other National Highway System
Note: This snail not be Interpreted as the ohlcial National Network nor shall it be used for truck size and weight enforcement purposes.
Source US Department of Transportation, Federal Highway Administration. Office of Freight Management and Operations, Freight Analysis Framework, version 22 2007.
1.4.6 Weigh Stations
Individual overweight trucks can damage roads and bridges; therefore, both federal
and state governments are concerned about trucks that exceed the maximum weight limits
operating without permits on U.S. roadways. In order to ensure that the trucks are operating
within the correct weight boundaries, weigh stations are distributed throughout the U.S.
roadways to ensure individual trucks are in compliance. In 2008, there were approximately
200 million truck weight measurements taken with less than one percent of those found to
have a violation.24
There are two types of weigh stations, dynamic, or 'weigh-in-motion', where the
operator drives across the scales at normal speed, and static scales where the operator must
stop the vehicle on the scale to obtain the weight. As of 2008, 60 percent of the scales in the
U.S. were dynamic and 40 percent were static. The main advantage of the dynamic weigh-in-
motion scales are that they allow weight measurements to be taken while trucks are operating
at highway speeds, reducing the time it takes for them to be weighed individually, as well as
reducing idle time and emissions.25'26 Officers at weigh stations are primarily interested in
ensuring the truck is compliant with weight regulations; however, they can also inspect
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
equipment for defects or safety violations, and review log books to ensure drivers have not
violated their limited hours of service.
1.4.7 Types of Freight Carried
Prior to 2002, the U.S. Census Bureau completed a "Vehicle Inventory and Use
Survey" (VIUS), which has since been discontinued. It provided data on the physical and
operational characteristics of the nation's private and commercial truck fleet, and had a
primary goal of producing national and state-level estimates of the total number of trucks.
The VIUS also tallied the amount and type of freight that was hauled by heavy-duty trucks.
The most prevalent type of freight hauled in 2002, according to the survey was mixed freight,
followed by nonpowered tools. Three fourths of the miles traveled by trucks larger than panel
trucks, pickups, minivans, other light vans, and government owned vehicles were for the
movement of products from electronics to sand and gravel. Most of the remaining mileage is
for empty backhauls and empty shipping containers, Table 1-7 shows the twenty most
commonly hauled types of freight in terms of miles moved.
Table 1-7 Top Twenty Types of Freight Hauled in 2002 in Terms of Mileage
TYPE OF PRODUCT CARRIER
Mixed freight
Tools, nonpowered
All other prepared foodstuffs
Tools, powered
Products not specified
Mail and courier parcels
Miscellaneous manufactured products
Vehicles, including parts
Wood products
Bakery and milled grain products
Articles of base metal
Machinery
Paper or paperboard articles
Meat, seafood, and their preparations
Non-metallic mineral products
Electronic and other electrical equipment
Base metal in primary or semi-finished forms
Gravel or rushed stone
All other agricultural products
All other waste and scrape (non-EPA manifest)
MILLIONS OF MILES
14,659
7,759
7,428
6,478
6,358
4,760
4,008
3,844
3,561
3,553
3,294
3,225
3,140
3,056
3,049
3,024
2,881
2,790
2,661
2,647
Source: The U.S. Census Bureau "Vehicle Inventory and Use Survey" 2002
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Regulatory Impact Analysis
1.4.8 Heavy-Duty Trucking Traffic Patterns
One of the advantages inherent in the trucking industry is that trucks can not only
carry freight over long distances, but due to their relatively smaller size and increased
maneuverability they are able to deliver freight to more destinations than other modes such as
rail. Figure 1-16 shows the different modes of freight transportation and the average length of
their routes. However, this also means they are in direct competition with light-duty vehicles
for road space, and that they are more prone to experiencing traffic congestion delays than
other modes of freight transportation.
Figure 1-16 Lengths of Routes by Type of Freight Transportation Mode
Internal (water)
Truck[a]
Lakewise (water)
Crude (oil pipeline)[b]
Class I rail
Coastwise (water)
Aircarrier
200 400 600 800 1,000 1,200 1,400
Miles
Source: http://www.bts.gov/publications/national_transportation_statistics/
The Federal Highway Administration (FHWA) projects that long-haul trucking
between places which are at least 50 miles apart will increase substantially on Interstate
highways and other roads throughout the U.S, forecast data indicates that this traffic may
reach up to 600 million miles per day.24 In addition, the FHWA projects that segments of the
NHS supporting more than 10,000 trucks per day will exceed 14,000 miles, an increase of
almost 230 percent over 2002 levels. Furthermore, if no changes are made to alleviate current
congestion levels, the FHWA predicts that these increases in truck traffic combined with
increases in passenger vehicle traffic could slow traffic overall on nearly 20,000 miles of the
NHS and create stop-and-go conditions on an additional 45,000 miles. Figure 1-17 shows the
projected impacts of traffic congestion. These predicted congestion areas would also have an
increase in localized engine emissions; advances in hybrid truck technology could provide
large benefits and help combat the increased emissions that occur with traffic congestion.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
Figure 1-17 Federal Highway Administration's Projected Average Daily Long-Haul Truck Traffic on the
National Highway System in 2035
National Highway System Routes
Note: Long-haul freight trucks serve locations at least 50 miles apart, excluding trucks that are used in intermoctal movements.
Source: The Federal Highway Administration: 2009 Facts and Figures
1.4.9 Intermodal Freight Movement
Since trucks are more maneuverable than other common modes of freight shipment,
trucks are often used in conjunction with these modes to transit goods across the country,
known as intermodal shipping. Intermodal traffic typically begins with containers carried on
ships, then they are loaded onto railcars, and finally transported to their end destination via
truck. There are two primary types of rail intermodal transportation which are trailer-on-
flatcar (TOFC) and container-on-flatcar (COFC), both are used throughout the U.S. with the
largest usage found on routes between West Coast ports and Chicago, and between Chicago
and New York. The use of TOFCs (see Figure 1-18) allows for faster transition from rail to
truck, but is more difficult to stack on a vessel; therefore the use of COFCs (see Figure 1-19)
has been increasing steadily.
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Regulatory Impact Analysis
Figure 1-18 Trailer-on-Flatcar (TOFC)
Figure 1-19 Container-on-Flatcar (COFC)
rrm bsgl o'nsl 578135. j pg
1.4.10 Purchase and Operational Related Taxes
Currently, there is a Federal retail tax of 12 percent of the sales price (at the first retail
sale) on heavy trucks, trailers, and tractors. This tax does not apply to truck chassis and bodies
suitable for use with a vehicle that has a gross vehicle weight of 33,000 pounds or less. It also
does not apply to truck trailer and semitrailer chassis or bodies suitable for use with a trailer
or semitrailer that has a gross vehicle weight of 26,000 pounds or less. Tractors that have a
gross vehicle weight of 19,500 pounds or less and a gross combined weight of 33,000 pounds
or less are excluded from the 12 percent retail tax.27 This tax is applied to the vehicles as well
as any parts or accessories sold on or in connection with the sale of the truck. However, idle
reduction devices affixed to the tractor and determined by the Administrator of the EPA, in
consultation of the Secretary of Energy and Secretary of Transportation are generally exempt
from this tax. There are other exemptions for certain truck body types, such as refuse packer
truck bodies with load capacities of 20 cubic yards or less, other specific installed equipment,
and sales to certain entities such as state or local governments for their exclusive use.
There is also a tire tax for tires used on some heavy-duty trucks. This tax is based on
the pounds of maximum rated load capacity over 3,500 pounds rather than the actual weight
of the tire, as was done in the past.28 Singlewide tires can provide some tax savings both in
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
terms of a lower tax rate and the weight reduction achieved as these tires typically weigh less
than two standard tires, mostly due to the elimination of two sidewalls.
A new method of calculating the federal excise tax (FET) on tires was included in the
American Jobs Creation Act that changed the method for calculating the FET on truck tires.
Previously, the tax was based on the actual weight of the tire, where before, for a tire
weighing more than 90 pounds there was a 500 tax for every 10 pounds of weight above 90
pounds plus a flat fee of $10.50. Since truck and trailer tires can weigh on average 120
pounds, this would carry a tax penalty of approximately $25 per tire; this method gave
singlewide tires a tax advantage as they weigh less in part because they have two fewer
sidewalls. The new FET is based on the load-carrying capacity of the tire. For every 10-
pound increment in load-carrying capacity above 3,500 pounds, a tax of 9.450 cents is levied.
A typical heavy-duty tire has a load carrying capacity of over approximately 6,000 pounds
9Q
and would therefore carry a similar tax burden as before. The change, however, is that the
tax rate for bias ply and single wide tires is half that of a standard tire.
Finally, there is a usage tax for heavy duty vehicles driven over 5,000 miles per year
(or over 7,500 miles for agricultural vehicles). This tax is based on the gross weight of the
truck, and includes a rate discounted 25 percent for logging trucks.30 For trucks with a GVW
of 55,000 - 75,000 pounds the tax rate is $100 plus $22 for each additional 1,000 pounds in
excess of 55,000 pounds; trucks with a GVW over 75,000 pay $550.
1.4.11 Heavy-Duty Vehicle Age Trends
Class 8 long-haul combination tractors are typically sold after the first three to five
years of ownership and operation by large fleets, however, smaller fleets and owner-operators
will continue to use these trucks for many years thereafter.31 As of 2009, the average age of
the U.S. Class 8 fleet was 7.87 years.32 These newest trucks travel between 150,000 -
200,000 miles per year, and 50 percent of the trucks in this Class 8 segment use 80 percent of
the fuel.33 Although the overall fleet average age is less than ten years old, Figure 1-20 shows
that nearly half of all of Class 4-8 trucks live well past 20 years of age, and that smaller Class
4-6 trucks typically remain in the U.S. fleet longer than other classes.
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Regulatory Impact Analysis
Figure 1-20 Survival Probability of Class 4-8 Trucks
100%
I~
B
3
o
i_
CL
01
>
5
*
I
3 5 7 9 __ 13 15 17 19 ' 23 25 27 29 31 33 35
-AII4-5-6
Class 8 Others
-Class 7 Others
-Class 7 Tractor-Trailer
-Class B Tractor Trailer
Source: Polk, 2008
1.5 Tire Manufacturers
The three largest suppliers to the U.S. commercial new truck tire market (heavy-duty
truck tires) are Bridgestone Americas Tire Operations LLC, Goodyear Tire and Rubber
Company, and Michelin North America, Incorporated. Collectively, these companies account
for over two-thirds of the new commercial truck tire market. Continental Tire of the
Americas LLC, Yokohama Tire Company, Toyo Tires U.S.A. Corporation, Hankook Tire
America Corporation, and others also supply this market. New commercial tire shipments
totaled 12.5 million tires in 2009. This number was down nearly 20 percent from the previous
year, due to the economic downturn, which hit the trucking industry especially hard
34
1.5.1 Single Wide Tires
A typical configuration for a combination tractor-trailer is five axles and 18 wheels
and tires, hence the name, "18-wheeler." There are two wheel/tire sets on the steer axle, one
at each axle end, and four wheel/tire sets on each of the two drive and two trailer axles, with
two at each axle end (dual tires), Figure 1-21 shows the position and name of each axle.
Steer tires and dual drive and trailer tires vary in size. A typical tire size for a tractor-
trailer highway truck is 295/75R22.5. This refers to a tire that is 295 millimeters (or 11.6")
wide with an aspect ratio (the sidewall height to tire section width, expressed as a percent) of
75, for use on a 22.5" wheel. The higher the aspect ratio the taller the tire is relative to its
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
section width. Conversely, the lower the aspect ratio the shorter the tire is relative to its
section width. Truck tires with a sidewall height between 70 percent and 80 percent of the
tire section width use this metric sizing; other common highway truck tire sizes are
275/80R22.5, 285/75R24.5, and 275/80R24.5. Tire size can also be expressed in inches.
11R22.5 and 11R24.5 refer to tires that are 11 inches wide for use on a 22.5" and 24.5" wheel,
respectively. Tires expressed in this non-metric nomenclature typically have an aspect ratio
of 90, meaning the sidewall height is 90 percent of the tire section width.
Figure 1-21 Class 8 Standard "18 Wheeler" Axle Identification
Single wide tires have a much wider "base" or section width than tires used in dual
configurations and have a very low aspect ratio. A typical size for a single wide tire used on a
highway tractor trailer is 455/50R22.5. This refers to a tire that is 455 millimeters wide with a
sidewall height that is 50 percent of its section width, for use on a 22.5" wheel. As implied by
its name, a single wide tire is not installed in a dual configuration. Only one tire is needed at
each end of the four drive and trailer axles, effectively converting an "18-wheeler" heavy-
duty truck into a 10-wheeler, including the two steer tires. Except for certain applications like
refuse trucks, in which the additional weight capacity over the steer axle could be beneficial,
single wide tires are not used on the steer axle.
Proponents of single wide tires cite a number of advantages relative to conventional
dual tires. These include lower weight, less maintenance, and cost savings from replacing 16
dual tire/wheel sets with 8 single wide tire/wheel sets; improved truck handling and braking,
especially for applications like bulk haulers that benefit from the lower center of gravity;
reduced noise; fewer scrapped tires to recycle or add to the waste stream; and better fuel
economy. A recent in-use study conducted by the Department of Energy's Oak Ridge
National Laboratory found fuel efficiency improvement for single wide tires compared to dual
tires of at least 6 percent up to 10 percent. These findings are consistent with assessments by
EPA using vehicle simulation modeling and in controlled track testing conducted by EPA's
SmartWay program.
35
Sales of single wide tires have grown steadily since today's single wide tires entered
the U.S. market in 2000. However, overall market share of single wide tires is still low
relative to dual tires. There are several reasons why trucking fleets or drivers might be slow
to adopt single wide tires. Fleets might be concerned that in the event of a tire failure with a
single wide tire, the driver would need to immediately pull to the side of the road rather than
"limping along" to an exit. "Limping along" on one dual tire after the other dual tire fails
places the entire weight of the axle end on the one remaining good tire. In most cases, this is
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Regulatory Impact Analysis
a dangerous practice that should be avoided regardless of tire type; however, some truck
operators still use "limp along" capability. Fleets might also be concerned that replacement
single wide tires are not widely available on the road. As single wide tires continue to gain
broader acceptance, tire availability will increase for road service calls. Trucking fleets might
not want to change tire usage practices. For example, some fleets like to switch tires between
the steer and trailer axles or retreaded steer tires for use on trailers. Since single wide tires are
not used on the steer position of tractor-trailers, using single wide tires on the trailer
constrains steer-trailer tire and retreaded tire interchangeability.
New trucks and trailers can be ordered with single wide tires, and existing vehicles can
be retrofit to accommodate single wide tires. If a truck or trailer is retrofit with single wide
tires, the dual wheels will need to be replaced with wider single wheels. Also, if a trailer is
retrofit or newly purchased with single wide tires, it may be preferable to use the heavier,
non-tapered "P" type trailer axles rather than the narrow, lighter, tapered "N" spindle axles,
because of changes in load stress at the axle end. Single wide tires are typically outset by 2
inches due to the wider track width, and outset wheels may require a slight de-rating of the
hub load. Industry is developing advanced hub and bearing components optimized for use
with single wide wheels and tires, which could make hub load de-rating unnecessary.
Whatever type of wheels and tires are used, it is important that trucking fleets follow the
guidance and recommended practices issued by equipment manufacturers, the Tire and Rim
Association, and the American Trucking Association's Technology and Maintenance Council,
regarding inflation pressure, speed and load ratings.
When today's single wide tires were first introduced in 2000, there were questions
about adverse pavement impacts. This is because in the early 1980's, a number of "super
single" tires were marketed which studies subsequently showed to be more detrimental to
pavement than dual tires. These circa-1980s wide tires were fundamentally different than
today's single wide tires. They were much narrower (16 percent to 18 percent) and taller,
with aspect ratios in the range of 70 percent, rather than the 45-55 percent of today's single
wide tires. The early wide tires were constructed differently as well, lacking the engineering
sophistication of today's single wide tires. The steel belts were oriented in a way that
concentrated contact stresses in the crown, leading to increased pavement damage. The tires
also flexed more, which increased rolling resistance.
In contrast, today's single wide tires are designed to provide more uniform tire-
pavement contact stress, with a tire architecture that allows wider widths at low aspect ratios
and reduces the amount of interaction between the crown and sides of the tire, to reduce
flexing and improve rolling resistance. Research on pavement response using instrumented
roads and finite element modeling shows that depending upon pavement structure, single wide
tires with a 55 percent aspect ratio produce similar bottom-up cracking and rutting damage as
dual tires, and improve top-down cracking. Single wide tires with a 45 percent aspect ratio
showed slightly more pavement damage. The new studies found that earlier research failed to
take into account differences in tire pressure between two tires in a dual configuration; a
situation that is common in the real world. Uneven inflation pressure with dual tire
configurations can be very detrimental to pavement. The research also found that
conventional steer tires damage pavement more than other tires, including single wide tires.36
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
Research is ongoing to provide pavement engineers the data they need to optimize road and
pavement characteristics to fit current and emerging tire technologies.
1.5.2 Retreaded Tires
Although retreading tires is no longer a common practice for passenger vehicles, it is
very common in commercial trucking. Even the federal government is directed by Executive
Order to use retreaded tires in its fleets whenever feasible.37 Retreading a tire greatly
increases its mileage and lifetime, saving both money and resources. It costs about one-third
to one-half of the cost of a new truck tire to retread it, and uses a lot less rubber. On average,
it takes about 325 pounds of rubber to produce a new medium- or heavy-duty truck tire, but
only about 24 pounds of rubber to retread the same tire.38
The Department of Transportation Federal Motor Carrier Safety Administration
(FMSCA) issues federal regulations that govern the minimum amount of tread depth
allowable before a commercial truck tire must be retreaded or replaced. These regulations
prohibit "Any tire on any steering axle of a power unit with less than 4/32 inch tread when
measured at any point on a major tread groove. ... All tires other than those found on the
steering axle of a power unit with less than 2/32 inch tread when measured at any point on a
major tread groove."39 Trucking fleets often retread tires before tire treads reach this
minimum depth in order to preserve the integrity of the tire casing for retreading. If the
casing remains in good condition, a truck tire can be safely retreaded multiple times. Heavy
truck tires in line haul operation can be retread 2 to 3 times and medium-duty truck tires in
urban use can be retread 5 or more times.40 To accommodate this practice, many commercial
truck tire manufacturers warranty their casings for up to five years, excluding damage from
road hazards or improper maintenance.
In 2009, the number of retreaded tires sold to the commercial trucking industry
outsold the number of new replacement tire shipments by half a million units - 13 million
retreaded tires were sold, versus 12.5 million replacement tires.41 Retreaded tire sales
(without casings) totaled $1.64 billion in 2009.42 All the top commercial truck tire
manufacturers are involved in tire retread manufacturing. Bridgestone Bandag Tire Solutions
accounts for 42 percent of the domestic retreaded truck tire market with its Bandag retread
products; Goodyear Tire and Rubber Company accounts for 28 percent, mostly through its
Wingfoot Commercial Tire Systems; Michelin Retread Technologies Incorporated, with
Megamile, Oliver, and Michelin retread products, accounts for 23 percent. Other tire
companies like Continental and independent retread suppliers like Marangoni Tread North
America (which also produces the Continental "ContiTread" retread product) make up the
remaining 7 percent.43
Although the "big 3" tire companies produce the majority of retread products through
their retread operations, the retreading industry itself consists of hundreds of retreaders who
sell and service retreaded tires, often (but not always) using machinery and practices
identified with one of the "big 3" retread producers. There are about 800 retread plants in
North America.44 The top 100 retreaders in the U.S. retread 47,473 truck tires per day. They
also retread 2,625 light truck tires and 625 off road tires daily. Tire retreaders are industry -
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Regulatory Impact Analysis
ranked by the amount of rubber they use annually in their businesses. In 2009, the top 12
retreaders in the US accounted for nearly 150 million pounds of rubber used to retread tires. 45
1.6 Current U.S. and International GHG Voluntary Actions and
Regulations
Heavy-duty trucks in the U.S. today are not required to meet national GHG standards
or regulations. The only national requirement for heavy-duty trucks is currently for non-GHG
emissions, as the heavy-duty engines must meet Non-Methane Hydrocarbons (NMHC),
nitrous oxides (NOx), particulate matter (PM), and carbon monoxide (CO) standards. U.S.
efforts to reduce GHG emissions from the heavy-duty truck sector to date have been limited
to voluntary measures and actions by the States. Congress has mandated the U.S. Department
of Transportation to take action to set fuel efficiency standards for heavy-duty trucks through
the Energy Independence and Security Act (EISA) of 2007. International GHG regulations
have been implemented in Japan and are under consideration in other countries.
Additionally, there are existing heavy-duty engine certification and useful life
requirements, as shown for example in Figure 1-22. Heavy-Duty Engines have a single full
life standard. Manufacturers certify results are cleaner than their test results to account for
production and testing variability. Manufacturers also develop a deterioration factor which is
used to demonstrate compliance at end of life.
Figure 1-22 Current Heavy-Duty Useful Life Years and Miles
ENGINE TYPE
Spark Ignited (SI) Engines
Light Heavy-Duty Diesel Engines
Medium -Heavy Duty Diesel
Engines
Heavy-Heavy-Duty Diesel
Engines
YEARS
10
10
10
10
MILES
110,000
110,000
185,000
435,000
1.6.1 U.S. EPA SmartWay™ Transport Partnership
While there are currently no national regulations for the heavy-duty trucking sector,
there is a highly recognized voluntary program established in the U.S. The U.S. EPA
SmartWay Transport Partnership is a collaborative program between EPA and the freight
industry that will increase the energy efficiency of heavy-duty trucks while significantly
reducing air pollution and GHG emissions. The Partnership provides strong market-based
incentives to companies shipping products and the truck companies delivering these products,
to improve the environmental performance of freight operations. SmartWay Transport
partners improve their energy efficiency, save money, reduce greenhouse gas emissions and
improve air quality.
SmartWay is a collaborative effort between the government and business, to improve
the efficiency of goods movement from global supply chains while reducing fuel consumption
and emissions. SmartWay was launched by the Environmental Protection Agency in 2004
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
with full support of the trucking industry and their freight shipping customers. SmartWay
started with fifty initial partners including 15 Charter Partners. Since that time, the number of
Partners has grown to over 2,700 members including most of the largest trucking fleets in the
United States, and many of the largest multi-national shippers. SmartWay trucking fleet
partners operate over 650,000 trucks, which represent 10 percent of all heavy-duty trucks.
The SmartWay program promotes the benefits of key truck technologies including idle
reduction, aerodynamics, efficient tires, and operational strategies that include enhanced
logistics management, reduced packaging, driver training, equipment maintenance, and
intermodal options. SmartWay partners employ these strategies and technologies on new and
existing equipment to reduce emissions and save fuel, contributing to environmental, energy
security, and economic goals. SmartWay partners have helped to reduce CO2 emissions
from trucks by nearly 15 million metric tons, NOx by 215,000 tons, and PM by 8,000 tons,
and have saved 1.5 billion gallons of diesel fuel as well as $3.6 billion in fuel costs. Other
countries have expressed significant interest in SmartWay, and EPA has participated in
workshops and pilot projects to demonstrate SmartWay tools and approaches internationally.
Beginning in 2007, working with truck, trailer and engine manufacturers as well as states and
public interest groups, SmartWay developed specifications to designate the cleanest and most
efficient Class 8 tractor-trailers. SmartWay-certified trucks now represent more than 5
percent of new Class 8 sleeper truck sales, and every major truck maker offers at least one
EPA SmartWay Certified Tractor.
1.6.2 The 21st Century Truck Partnership
Additionally, the DOE, EPA, DOT, Department of Defense (DOD), and national
laboratories together with members of the heavy-duty truck industry work toward making
freight and passenger transportation more efficient, cleaner, and safer under the 21st Century
Truck Partnership.46 The Partnership has several activities related to reducing greenhouse gas
emissions, including:
• Integrated vehicle systems research and development to validate and deploy
advanced technologies.
• Research for engine, combustion, exhaust aftertreatment, fuels, and advanced
materials to achieve both higher efficiency and lower emissions.
• Research on advanced heavy-duty hybrid propulsion systems, reduced parasitic
losses, and reduced idling emissions.
The Partnership provides a forum for parties to exchange information on the heavy-
duty sector across government and industry. The Partnership has developed, among many
other aspects, the widely referenced vehicle energy balance for heavy trucks and specific
research goals for improvement efficiency.
1.6.3 California Assembly Bill 32
The state of California passed the Global Warming Solutions Act of 2006 (Assembly
Bill 32), enacting the state's 2020 greenhouse gas emissions reduction goal into law.
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Regulatory Impact Analysis
Pursuant to this Act, the California Air Resource Board (ARB) was required to begin
developing early actions to reduce GHG emissions. Accordingly, the California Air Resource
Board issued the Regulation to Reduce Greenhouse Gas Emissions from Heavy-Duty
Vehicles in December 2008. 47
This regulation reduces GHG emissions by requiring improvement in the efficiency of
heavy-duty tractors and 53 foot or longer dry and refrigerated box trailers which operate in
California. The program begins in 2010, although small fleets are allowed special compliance
opportunities to phase in the retrofits of their existing trailer fleets through 2017. The
regulation requires that new tractors and trailers subject to the rule be certified by SmartWay
and existing tractors and trailers are retrofit with SmartWay verified technologies. The
efficiency improvements are achieved through the use of aerodynamic equipment and low
rolling resistance tires on both the tractor and trailer.
1.6.4 U.S. Energy Independence and Security Act
The U.S. Energy Independence and Security Act (EISA) of 2007 was enacted by
Congress in December of 2007.48 EISA requires the Department of Transportation, in
consultation with DOE and EPA, to study the fuel efficiency of heavy-duty trucks and
determine: the appropriate test procedures and metric for measuring and expressing fuel
efficiency; of MD/HD vehicles; the range of factors that affect fuel efficiency of such
vehicles; and factors that could have an impact on a program to improve these vehicles' fuel
efficiency. In addition, EISA directed the Department of Transportation, in consultation with
DOE and the EPA, to implement, via rulemaking and regulations, "a commercial heavy-duty
on-highway vehicle and work truck fuel efficiency improvement program" and to "adopt and
implement appropriate test methods, measurement metrics, fuel economy standards, and
compliance and enforcement protocols that are appropriate, cost-effective, and
technologically feasible for commercial heavy-duty on-highway vehicles and work trucks."
This authority permits DOT to set "separate standards for different classes of vehicles." The
standards must provide at least 4 full model years of regulatory lead time and 3 full model
years of regulatory stability.
Section 108 of the Act directed the Secretary of Transportation to execute an
agreement with the National Academy of Sciences (NAS) to develop a report evaluating
heavy-duty truck fuel economy standards. The study included an assessment of technologies
and costs to evaluate MD/HD vehicle fuel economy; an analysis of existing and potential
technologies to improve such vehicles' fuel economy; analysis of how the technologies may
be integrated into the manufacturing process; assessment of how technologies may be used to
meet fuel economy standards; and associated costs and other impacts on operation. The NAS
panel published this study, titled "Technologies and Approaches to Reducing the Fuel
Consumption of Medium- and Heavy-duty Vehicles" March 31, 2010."
1.6.5 International GHG Emissions Activities
The international regulatory actions to reduce GHG emissions from heavy-duty trucks
have been limited in scope. Japan has been at the forefront of heavy-duty truck GHG
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regulations while other nations, such as China and the European Union, are still in the
development stage of potential regulatory programs for this sector.
Japan introduced legislation which set the minimum fuel economy standards for new
heavy-duty vehicles with Gross Vehicle Weight Rating (GVWR) of greater than 7,700 pounds
beginning in 2015 model year.
1.7 Trailers
1.7.1 Overview
A trailer is a vehicle designed to haul cargo while being pulled by another powered
motor vehicle. It may be constructed to rest upon the tractor that tows it (a semi-trailer), or be
constructed so no part of its weight rests on the tractor (a full trailer or a semitrailer equipped
with an auxiliary front axle called a "converter dolly.") The most common configuration of
large freight trucks consists of a Class 7 or 8 tractor hauling one or more semi-trailers. A
truck in this configuration is called a "tractor-trailer." The semi-trailer is attached to the
tractor by a coupling consisting of a horseshoe-shaped coupling device called a fifth wheel on
the rear of the towing vehicle, and a coupling pin (or kingpin) on the front of the semi-trailer
or converter dolly. A tractor can also pull an ocean container mounted on an open-frame
chassis, which when driven together on the road functions as a trailer. The Department of
Transportation issues federal regulations that govern trailer length (separately or in
combination), width, height, and weight, as well as trailer safety requirements (lights,
reflective materials, bumpers, turn signals, tire and rim specifications, brakes, load-securing
devices, tow balls, etc.) The Truck Trailer Manufacturers Association, an industry trade
group for manufacturers of Class 7 and 8 truck trailers, also provides technical bulletins
covering many aspects of trailer manufacture. Each trailer, like any other road vehicle, must
have a Vehicle Identification Number (VIN).
1.7.2 Trailer Types
There are numerous types of trailers hauled by Class 7 and 8 tractors that are designed
to handle any freight transport need. Dry box van trailers are enclosed trailers that can haul
most types of mixed freight. Despite their similar shape and purpose, box trailers can vary
widely in size and configuration although most are commonly found in 28', 48', and 53'
lengths and 102" or 96" widths. Drop floor trailers have a lowered floor, often seen in
moving vans. Other van trailers are curtain-sided with tarp or have roll up doors on the sides,
as seen in beverage haulers. Another type of specialty box trailer is the refrigerated van trailer
(reefer). This is an enclosed, insulated trailer that hauls temperature sensitive freight, with a
transportation refrigeration unit (TRU) mounted in the front of the trailer powered by a small
(9-36 hp) diesel engine. Enclosed box trailers - whether dry van, reefer, curtainside, drop
floor, or other configuration, can have different axle configurations (single axle, fixed tandem,
sliding tandem, tag-along axle) and door types (roll up, side-by-side). Figure 1-23 shows an
example of a dry freight van semi-trailer with side-by-side doors.
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Figure 1-23 Example Dry Box Van Trailer
1) Composite Panel Sidewall
Design
2) Anti-Snag Roof Bows
3) DuraPlate Doors
4) LED Upper Front and Rear
Marker Lights
5) Bolted Crossmember
Connections
6) P-Spindle Wheel Ends
7) Long Life Brake Linings
8) Long Stroke Brake
Chambers
9) Powder-Coated Rear Frame
Source: http://www.wabashnational.com/lmages/popups/DuraPlatePop.jpg
Flatbed trailers are platform-type trailers which also come in different configurations
from standard flatbed platform trailers to gooseneck and drop deck flatbeds which are built
such that the trailer platform is lower to the ground than the hitch would normally allow.
There are also a number of other specialized trailers such as grain trailers (with and without
hoppers), dump trailers (frameless, framed, bottom dump, demolition), automobile hauler
trailers (open or enclosed), livestock trailers (belly or straight), dry bulk and liquid tanker
trailers, construction and heavy-hauling trailers (tilt bed, hydraulic), even trailers designed to
travel on both highways and railroad tracks. Figure 1-24 shows an example of a drop-deck
platform trailer.
Figure 1-24 Example Drop-Deck Trailer
Source: http://www.transcraft.com/Transcraft/images/products/D-Eagle.jpg
The most common type of trailer in use today is the dry van trailer. Table 1-8 shows
the various trailer types and their share of the trucking market. Despite considerable
improvements in suspension, material, safety, durability, and other advancements, the basic
shape of the van trailer has not changed much over the past decades, although its dimensions
have increased incrementally from what used to be the industry's standard length of 40' to
today's standard 53' long van trailer. The van trailer's boxy shape - while not particularly
aerodynamic - is designed to maximize cargo volume hauling capacity, since the majority of
freight shipped by truck cubes out (is volume-limited) before it grosses out (is weight-
limited). EPA's SmartWay program has demonstrated that adding aerodynamic features to
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van trailer designs and the use of low rolling resistance tires can substantially reduce fuel
consumption from tractor trailers. SmartWay verifies aerodynamic equipment and low
rolling resistance tires for use on SmartWay-certified trailers, which can be new or retrofit.
Table 1-8 Trailer Types and Volumes (Source: ICCT Report)
Beverage, 0%—i
Tank Pneumatic, O%-A)I other, 9%
TankMC,
Tank, 1%^
Flatbed Drop Deck, 2%—.
Flatbed, 7%
Container Chassis, 6%
Enclosed Tagalong, 2%
Tagalong, 3%
Van Refrigerated, 4%
Van, 55%
1.7.3 Trailer Manufacturers
This diverse variety of van, platform, tanker and specialty trailers are produced by a
large number of trailer manufacturers. The twelve manufacturers with the largest overall
North American output are: Utility Trailer Manufacturing, Great Dane Limited Partnership,
Wabash National Corporation, Hyundai Translead, Timpte Inc., Wilson Trailer Company,
Stoughton Trailers, Heil Trailer International, Fontaine Trailer Company, MANAC, Vanguard
National Trailer Corporation, and Polar Tank Trailer. Trailer manufacturing is still done
mostly by hand, although the various trailer parts can be mass-produced and even shipped
from abroad for assembly in the U.S. Altogether, 30-some companies account for most of
this industry's manufacturing base, although there are dozens and dozens additional
manufacturers producing for niche trailer markets. Despite this variety, trailers are far less
mechanically complex than are the trucks that haul them. This low barrier to entry for trailer
manufacturing accounts in part for the large numbers of trailer manufacturers. Nearly half of
all trailer manufacturers - including those that might be considered "large" in their industry
segment — meet SBA's definition of a small business.
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The trailer industry was particularly hard hit by the recent recession. Trailer
manufacturers saw deep declines in new trailer sales of 46 percent in 2009; some trailer
manufacturers saw sales drop as much as 71 percent. This followed overall trailer industry
declines of over 30 percent in 2008. The 30 largest trailer manufacturers saw sales decline
72% overall from their highest recent sales volumes, from 277,992 in 2006, to only 78,258 in
2009. 49 Several trailer manufacturers shut down entire production facilities and a few went
out of business altogether. Of the most common trailer types of trailers sold, refrigerated
trailers were the least affected; platform trailers were the most affected. As of mid-2010, the
trailer industry has yet to recover from the devastating effects of the economic downturn.
1.7.4 Trailer Operations
Trailers are the primary vehicle for moving freight in the United States. Despite their
significance to the goods movement industry and opportunities to improve fuel efficiency and
reduce greenhouse gas emissions from trailer improvements, the broad diversity of the trailer
industry and its end-user practices make this a challenging industry to address and engage.
Truck drivers and trucking fleets frequently do not control all or even any of the
trailers that they haul. Trailers can be owned by freight customers, large equipment leasing
companies, third party logistics companies (3PLS), and even other trucking companies.
Containers on chassis, which function as trailers, are rarely owned by truck operators. Rather,
they are owned or leased by ocean-going shipping companies, port authorities or others. This
distinction between who hauls the freight and who owns the equipment in which it is hauled
means that truck owners and operators have limited ability to be selective about the trailers
they carry, and very little incentive or ability to take steps to reduce the fuel use of trailers that
they neither own or control.
The ratio of the number of trailers in the fleet relative to the number of tractors in the
legacy fleet is typically three-to-one.50 At any one time, two trailers are typically parked
while one is on the road. For certain private fleets, this ratio can be greater, as high as six-to-
one. This means that on average a trailer will travel only one third of the miles travelled by a
tractor. Lower annual mileage combined with the less complex machinery of a trailer mean
that trailers do not need to be purchased as frequently as the trucks that haul them. The initial
owner may keep a trailer for a decade or even longer; typically, the initial owner of a Class 7
or 8 tractor keeps his or her vehicle for three to six years. Less frequent procurement cycles
result in slower turnover of trailers in the in-use fleet, with many older trailers still in use.
For refrigerated trailers, the story is slightly different. These trailers are used more
intensely and accumulate more annual miles than other trailers. Over time, refrigerated
trailers can also develop problems that interfere with their ability to keep freight temperature-
controlled. For example, the insulating material inside a refrigerated trailer's walls can
gradually lose its thermal capabilities due to aging or damage from forklift punctures. The
door seals on a refrigerated trailer can also become damaged or loose with age, which greatly
affects the insulation characteristics of the trailer, similar to how the door seal on a home
refrigerator can reduce the efficiency of that appliance. As a result of age-related problems
and more intense usage, refrigerated trailers tend to have shorter procurement cycles than dry
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van trailers, which means a faster turnover rate, although still not nearly as fast as for trucks in
their first use.
1.8 Hybrids
Following the trends in the lighter duty passenger vehicles, heavy-duty trucks are
starting to look at hybrid vehicles to help optimize their performance and exhaust emissions.
There are three primary hybrid designs that can be applied to heavy-duty trucks and vehicles
including: hydraulic, electric, and 'plug-in' which are discussed in more detail below.
Typically, trucks that have shorter or 'stop and go' type operations, such as utility (bucket)
trucks, pickup and delivery, refuse, busses, and combination tractors, are the best candidates
for a hybrid vehicle. On average, the conventional annual sales for these truck types range
from 10,000 - 150,000 units per year.
Hydraulic hybrids use a combination of pumps, motors, and accumulators in
conjunction with the diesel engine. The engine powers a hydraulic pump-motor, which
charges a high-pressure accumulator, which in turn drives an additional pump-motor at the
rear of the vehicle to provide propulsion. There are two main types of hydraulic hybrids, those
that operate in parallel and those that operate in series. The parallel hydraulic vehicle has a
conventional driveline that is supplemented by hybrid (also known as hydraulic launch assist).
This type of vehicle is best suited for stop-and-go duty cycles such as refuse and bus.
The series style hydraulic hybrid vehicle does not have a conventional driveline as it
is replaced by hybrid system; therefore, the transmission is removed. This allows the engine
to operate in a "sweet spot", and to shut-off the engine when it is not needed. These vehicle
types have broader applications than the parallel hybrids, but their best benefit is still in stop-
and-go duty cycles. Typical applications for these hybrids include refuse, commercial
construction, yard hostler, etc.
Electric hybrids operate by combining the traditional internal combustion engine with
an electric propulsion system. There are several types of electric hybrid combinations within
the heavy-duty fleet. Motive type blends diesel and electric power as demanded and operates
in a parallel system. Motive & Auxiliary power type hybrid provides motive power from
diesel and electric motors and provides electric auxiliary power to the vehicle. Dual Mode
hybrid operates as a series hybrid at low speeds and parallel hybrid at higher speeds. Typical
applications for electric hybrids include utility, bus, pickup and delivery, etc.
The third type of HD hybrid design is a 'plug-in' which operates on the same principle
as the electric hybrid only adds the capability to recharge the hybrid battery using an external
power source. These trucks can use electric power for auxiliary system power and operations
and can have range-extended batteries as they can switch propulsive power to the diesel
engine when the battery runs low. Typical applications for this type of vehicle include utility
(powering the grid), small pickup and delivery trucks, and shuttle buses.
There are many companies currently designing, demonstrating, and / or producing
hybrid systems for the HD trucking industry, as well as industry associations such as Hybrid
Truck Users Forum (H-TUF), Next Energy Hydraulic Hybrid Working Group, and the
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Regulatory Impact Analysis
Electric Drive Transportation Association. By creating these vehicles for the HD industry,
CC>2, NOx, HC, and PM emissions will all be reduced, the vehicle's overall noise will be
reduced due to engine-off idling, and owners should notice a reduction in maintenance and
operating costs as there is reduced usage of brakes and engine operating hours.
Today for hybrid trucks there are several incentive programs in place. The federal
government has Federal Tax incentives, for purchasers to receive up to 40 percent of the
incremental cost of the hybrid, dependent on the fuel economy improvement. Additionally,
there are currently 13 states that have hybrid incentive programs, and some of the smaller
localities also have incentive programs. Government funding through programs such as the
National Clean Diesel Program, SmartWay, Clean Automotive Technology, and Clean Cities
is also available.
As with any new technology, there are some issues that arise with hybrid technologies.
For example the overall system cost is generally more than conventional power systems, and
some of the battery technology (such as size, weight, cold weather operations, charging time,
etc) is still relatively untested - and in some cases - unknown. Additionally, to maximize the
efficiency of the vehicle, the hybrid technology needs to be properly matched to the
applicable duty cycle, and the engines need to be properly optimized for the vehicle and its
operation.
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References
1 2009 Bureau of Transportation: Facts and Figures
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18 From the 2009 FHWA report which used the following Sources: Total, water and air data: U.S. Department of
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Merchandise DVD's, December 2008. Truck, rail, and pipeline data: U.S. Department of Transportation,
Research and Innovative Technology Administration, Bureau of Transportation Statistics, Transborder Freight
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Regulatory Impact Analysis
Data, available at www.bts.gov/transborder as of August 20, 2009. Other, unknown and miscellaneous data:
special tabulation, August 2009.
19 U.S. Department of Commerce, International Trade Administration, Top Trade Partners statistics. Available
at: http://www.trade.gov/mas/ian/build/groups/public/@tg_ian/documents/webcontent/tg_ian_003020.pdf
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21 http://www.truckercountry.com/speed-limits.html. Accessed 07/20/2010.
22http://www.chicagocaraccidentlawyersblog.com/2009/08/illinois_increases_truck_speed.html
23 U.S. DOT and The Federal Highway Administration, Freight Management and Operations, available here:
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24http://www.ops.fhwa.dot.gov/freight/freight_analysis/nat_freight_stats/docs/09factsfigures/pdfs/fff2009_ch3.p
df
25http://training.ce.washington.edu/wsdot/Modules/04_design_parameters/wim.htm
26 http ://www. oregon.gov/ODOT/MCT/GREEN. shtml
27 http://www.irs.gov/publications/p510/ch06.html
28 http://www.irs.gov/pub/irs-pdf/i720.pdf
29http://www.tirebusiness.com/subscriber/comm_tire2.html?cat=12&id=1104858239&subtitle=
30 http://www.irs.gov/pub/irs-pdf/f2290.pdf
31 http://fleetowner.com/equipment/usedtruckblue/rethinking classS truck resales 1208/ Accessed: 08/03/2010
32 Mele, Jim, "Plotting the Recovery" January 1, 2010. Available at:
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33 U.S. DOE, Research and Development Opportunities for Heavy Trucks, June, 2009. Available at:
http://wwwl.eere.energy.gov/vehiclesandfuels/pdfs/truck_efficiency_paper_v2.pdf
34Modern Tire Dealer, Top Retreaders (April, 2010), accessed August 2, 2010, at
http ://www. moderntiredealer. com/Stats/Viewer. aspx?file=http%3 a%2f%2fwww. moderntiredealer. com%2ffiles
%2fstats%2fMTD06marketshare.pdf
35 US Department of Transportation, Effect of Tires on Class 8 Heavy Truck Fuel Efficiency, Franzese, Oscar,
Knee, Helmut (Bill), Slezak, Lee (July, 2009), accessed August 2, 2010, at
http://info.ornl.gov/sites/publications/files/Pub20686.pdf
36 Al-Qadi, Imad, and Wang, Hao, Evaluation of Pavement Damage Due to New Tire Design, Illinois Center for
Transportation, FHWA-ICT-09-048 (May, 2009).
Greene, James, Impact of Wide-Base Tires on Pavement Damage (April, 2010), accessed August 2, 1010, at
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Al-Qadi, Imad, Impact of Wide-Base Tires on Pavement and Trucking Operation, Illinois Center for
Transportation, presentation at the International Workshop on the Use of Wide-Base Tires, Federal Highway
Administration, Turner-Fairbank Highway Research Center (October, 2007), accessed August 2, 2010, at
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Base_Tires/International_Workshop_on_the_Use_of_ Widebase_Tires-Minutes-Final.pdf
37 White House, Executive Order 13149 of April 21, 2000, Greening the Government Through Federal Fleet and
Transportation Efficiency
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Industry Characterization
38 Modern Tire Dealer, Top Retreaders (April, 2010), accessed August 2, 2010, at
http ://www. moderntiredealer. com/Stats/Viewer. aspx?file=http%3 a%2f%2fwww. moderntiredealer. com%2ffiles
%2fstats%2fMTD-32-40-l.pdf
39 Appendix G to Subchapter B—Minimum periodic inspection standards: 49 CFR Subtitle B Chapter III
Subchapter B Appendix G
40 Todaystrucking.com, Retread Tires FAQ (07/17/2006), accessed August 2, 2010.
41 Modern Tire Dealer, Top Retreaders (April, 2010), accessed at
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%2fstats%2fMTD-32-40-l.pdf
42 Manges, Mike, Retreaders Look for a Better Year, Commercial Tire Dealer (February 19, 2010), accessed
August 2, 2010, at http://www.moderntiredealer.com/Article/Story/2010/02/Retreaders-look-for-better-year.aspx
43 Modern Tire Dealer, Top Retreaders, ibid.
44 Tire Industry Association and the Tire Retread and Repair Information Bureau, Understanding Retreading,
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45 Ulrich, Bob, Breaking Down the Top Retreaders, Modern Tire Dealer (June 7, 2009), accessed August 2,
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retreaders.aspx
46 U.S. Department of Energy, Energy Efficiency & Renewable Energy - Vehicle Technologies Program. 21st
Century Truck Partnership. Viewed 12/8/2009 at
http://wwwl.eere.energy.gov/vehiclesandfuels/about/partnerships/21centurytruck/
47 California Air Resource Board, Heavy-Duty Vehicle Greenhouse Gas Measure. Viewed 12/8/2009 at
http://www.arb.ca.gov/cc/hdghg/hdghg.htm
48 One Hundred Tenth Congress of the United States of America. Energy Independence and Security Act of
2007. January 2007. Viewed 12/8/2009 at http://frwebgate.access.gpo.gov/cgi-
bin/getdoc.cgi?dbname= 110_cong_bills&docid=f :h6enr.txt.pdf
49 Trailer Body Builders, 2009 North American Truck Trailer Output (Table - March 2010), and 2008 North
American Truck Trailer Output (Table - March 2009), both tables accessed August 2, 2010, at http://trailer-
bodvbuilders.com/trailer-output/output/2009-trailer-output-0301/. Also, Polk Commercial Vehicle Solutions,
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50 TIAX. "Assessment of Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles. November
2009. Page 4-49.
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
Effectiveness
Chapter 2: Technologies, Cost, and Effectiveness
2.1 Overview of Technologies
In discussing the potential for CC>2 emission and fuel consumption reductions, it can
be helpful to think of the work flow through the system. The initial work input is fuel. Each
gallon of fuel has the potential to produce some amount of work and will produce a set
amount of CC>2 (about 22 pounds of CO2 per gallon of diesel fuel). The engine converts the
chemical energy in the fuel to useable work to move the truck. Any reductions in work
demanded of the engine by the vehicle or improvements in engine fuel conversion efficiency
will lead directly to CC>2 emission and fuel consumption reductions.
Current diesel engines are 35-38 percent efficient over a range of operating conditions
with peak efficiency levels between 40 and 45 percent depending on engine sizes and
applications, while gasoline engines are approximately 30 percent efficient overall. This
means that approximately one-third of the fuel's chemical energy is converted to useful work
and two-thirds is lost to friction, gas exchange, and waste heat in the coolant and exhaust. In
turn, the truck uses this work delivered by the engine to overcome overall vehicle-related
losses such as aerodynamic drag, tire rolling resistance, friction in the vehicle driveline, and to
provide auxiliary power for components such as air conditioning and lights. Lastly, the
vehicle's operation, such as vehicle speed and idle time, affects the amount of total energy
required to complete its activity. While it may be intuitive to look first to the engine for CC>2
reductions given that only about one-third of the fuel is converted to useable work, it is
important to realize that any improvement in vehicle efficiency reduces both the work
demanded and also the waste energy in proportion.
Technology is one pathway to improve heavy-duty truck GHG emissions and fuel
consumption. Near-term solutions exist, such as those being deployed by SmartWay partners
in heavy-duty truck long haul applications. Other solutions are currently underway in the
Light-Duty vehicle segment, especially in the Large Pickup sector where many of the
technologies can apply to the heavy-duty pickup trucks covered under this proposal. Long-
term solutions are currently under development to improve efficiencies and cost-effectiveness.
While there is not a "silver bullet" that will significantly eliminate GHG emissions from
heavy-duty trucks like the catalytic converter has for criteria pollutant emissions, significant
GHG and fuel consumption reductions can be achieved through a combination of engine,
vehicle system, and operational technologies.
The following sections will discuss technologies in relation to each of the proposed
regulatory categories - Heavy-Duty Pickup Trucks and Vans, Heavy-Duty Engines, Class 7/8
Sleeper and Day Cabs, Class 2b-8 Vocational Vehicles, and Trailers.
EPA and NHTSA collected information on the cost and effectiveness of fuel
consumption and CC>2 emission reducing technologies from several sources. The primary
sources of information were the 2010 National Academy of Sciences report of Technologies
and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles
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(NAS)1, TIAX's assessment of technologies to support the NAS panel report (TIAX)2, EPA's
Heavy-Duty Lumped Parameter Model3, the analysis conducted by NESCCAF, ICCT,
Southwest Research Institute and TIAX for reducing fuel consumption of heavy-duty long
haul combination tractors (NESCCAF/ICCT)4, and the technology cost analysis conducted by
ICF for EPA (ICF).5 In addition, EPA's simplified vehicle simulation model plays a key role
in quantifying the effectiveness of various technologies on CC>2 emission and fuel
consumption reductions in terms of vehicle performance. The simulation tool is described in
DRIA Chapter 3 in more details.
2.2 Overview of Technology Cost Methodology
Section 2.2.1 presents the methods used to address indirect costs in this analysis. Section
2.2.2 presents the learning effects applied throughout this analysis. Section 2.10 presents a
summary in tabular form of all the technology costs expected to be implemented in response
to the proposed standards.
2.2.1 Markups to Address Indirect Costs
To produce a unit of output, engine and truck manufacturers incur direct and indirect
costs. Direct costs include cost of materials and labor costs. Indirect costs may be related to
production (such as research and development [R&D]), corporate operations (such as salaries,
pensions, and health care costs for corporate staff), or selling (such as transportation, dealer
support, and marketing). Similarly to direct costs, indirect costs are generally recovered by
allocating a share of the costs to each unit of good sold. Although it is possible to account for
direct costs allocated to each unit of good sold, it is more challenging to account for indirect
costs allocated to a unit of goods sold. To make a cost analysis process more feasible, markup
factors, which relate indirect costs to the changes in direct costs, have been developed. These
factors are often referred to as retail price equivalent (RPE) multipliers.
Cost analysts and regulatory agencies including the EPA have frequently used these
multipliers to predict the resultant impact on costs associated with manufacturers' responses
to regulatory requirements. Clearly the best approach to determining the impact of changes in
direct manufacturing costs on a manufacturer's indirect costs would be to actually estimate
the cost impact on each indirect cost element. However, doing this within the constraints of
an agency's time or budget is not always feasible, or the technical, financial, and accounting
information to carry out such an analysis may simply be unavailable.
RPE multipliers provide, at an aggregate level, the relative shares of revenues6 to
direct manufacturing costs. Using RPE multipliers implicitly assumes that incremental
changes in direct manufacturing costs produce common incremental changes in all indirect
cost contributors as well as net income. A concern in using the RPE multiplier in cost
analysis for new technologies (which result from regulations requiring reductions in
emissions) is that the indirect costs of vehicle modifications are not likely to be the same for
different technologies. For example, less complex technologies could require fewer R&D
efforts or less warranty coverage than more complex technologies. In addition, some simple
technological adjustments may, for example, have no effect on the number of corporate
personnel.
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To address this concern, modified multipliers have been developed. These multipliers
are referred to as indirect cost multipliers (or 1C multipliers). In contrast to RPE multipliers,
1C multipliers assign unique incremental changes to each indirect cost contributor as well as
net income.
1C multiplier = (direct cost + adjusted indirect cost)/(direct cost)
Developing the 1C multipliers from the RPE multipliers requires developing
adjustment factors based on the complexity of the technology and the time frame under
consideration. This methodology was used in the cost estimation for the recent Light-Duty
GHG rule. The agency has used ICM adjustment factors developed for light-duty vehicles
(with the exception that here return on capital has been incorporated into the ICMs, where it
had not been in the light-duty rule) for the heavy-duty pickup truck and van cost projections
in this proposal primarily because the manufacturers involved in this segment of the heavy-
duty market are the same manufacturers which build light-duty trucks.
For the Class 7/8 tractor, vocational vehicles, and heavy-duty engine cost projections
in this proposal, EPA contracted with RTI International to update EPA's methodology for
accounting for indirect costs associated with changes in direct manufacturing costs for heavy-
duty engine and truck manufacturers.7 In addition to the indirect cost contributors varying by
complexity and time frame, there is no reason to expect that the contributors would be the
same for engine manufacturers as for truck manufacturers. The resulting report from RTI
provides a description of the methodology, as well as calculations of new indirect cost
multipliers. These indirect cost multipliers are intended to be used, along with calculations of
direct manufacturing costs, to provide improved estimates of the full additional costs
associated with new technologies.
To account for the indirect costs on Class 2b and 3 trucks and on heavy-duty gasoline
engines, the agencies have applied an indirect cost multiplier (ICM) factor to all of the direct
costs to arrive at the estimated technology cost. The ICM factors used are shown in Table
2-1. Near term values (2014 through 2021 in this analysis) account for differences in the
levels of R&D, tooling, and other indirect costs that will be incurred. Once the program has
been fully implemented, some of the indirect costs will no longer be attributable to the
proposed standards and, as such, a lower ICM factor is applied to direct costs in 2022 and
later.
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Table 2-1 Indirect Cost Multipliers Used in this Analysis"
CLASS
2b&3 Trucks and Vans
Loose diesel engines
Loose gasoline engines
Vocational/Combination
Trucks
COMPLEXITY
Low
Medium
Highl
High2
Low
Medium
Highl
High2
Low
Medium
Highl
High2
Low
Medium
Highl
High2
NEAR TERM
1.17
1.31
1.51
1.70
1.11
1.18
1.28
1.43
1.17
1.31
1.51
1.70
1.14
1.26
1.42
1.57
LONG TERM
1.13
1.19
1.32
1.45
1.09
1.13
1.19
1.29
1.13
1.19
1.32
1.45
1.10
1.16
1.27
1.36
a Rogozhin, A., et. al, "Using indirect cost multipliers to estimate the total cost of adding new
technology in the automobile industry," International Journal of Production Economics (2009);
"Documentation of the Development of Indirect Cost Multipliers for Three Automotive
Technologies," Helfand, G., and Sherwood, T., Memorandum dated August 2009; "Heavy
Duty Truck Retail Price Equivalent and Indirect Cost Multipliers," Draft Report prepared by
RTI International and Transportation Research Institute, University of Michigan, July 2010
The agencies have also applied ICM factors to Class 2b through 8 vocational vehicle
and tractor technologies along with all heavy-duty diesel engine technologies. The ICMs
used in this analysis include a factor for profit that is a 0.05 share of direct costs, as calculated
in the RTI report, for the Class 7/8 tractor, vocational vehicles, and heavy-duty engine cost
projections; for the heavy-duty pickup truck and van cost projections, this analysis used a
profit factor of 0.06 from the RTI LD report. In the long run in a competitive industry, profits
should equal the return on capital investments necessary to sustain the industry. These capital
investments represent the fixed costs of the industry. Note that, for heavy-duty diesel engines,
the agencies have applied these markups to ensure that our estimates are conservative since
we have estimated fixed costs separately for technologies applied to these categories,
effectively making the use of markups a double counting of some of the indirect costs.
For most of the segments in this analysis, the indirect costs are estimated by applying
indirect cost multipliers (ICM) to direct cost estimates. ICMs were calculated by EPA as a
basis for estimating the impact on indirect costs of individual vehicle technology changes that
would result from regulatory actions. Separate ICMs were derived for low, medium, and high
complexity technologies, thus enabling estimates of indirect costs that reflect the variation in
research, overhead, and other indirect costs that can occur among different technologies.
ICMs were also applied in the MY 2012-2016 CAFE rulemaking.
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Previous CAFE rulemakings applied a retail price equivalent (RPE) factor to estimate
indirect costs and mark up direct costs to the retail level. Retail Price Equivalents are
estimated by dividing the total revenue of a manufacturer by the direct manufacturing costs.
As such, it includes all forms of indirect costs for a manufacturer and assumes that the ratio
applies equivalently for all technologies. ICMs are based on RPE estimates that are then
modified to reflect only those elements of indirect costs that would be expected to change in
response to a technology change. For example, warranty costs would be reflected in both
RPE and ICM estimates, while marketing costs might only be reflected in an RPE estimate
but not an ICM estimate for a particular technology, if the new technology is not one expected
to be marketed to consumers. Because ICMs calculated by EPA are for individual
technologies, many of which are small in scale, they often reflect a subset of RPE costs; as a
result, the RPE is typically higher than an ICM. This is not always the case, as ICM estimates
for complex technologies may reflect higher than average indirect costs, with the resulting
ICM larger than the averaged RPE for the industry.
Precise association of ICM elements with individual technologies based on the varied
accounting categories in company annual reports is not possible. Hence, there is a degree of
uncertainty in the ICM estimates. If all indirect costs moved in proportion to changes in
direct costs the ICM and RPE would be the same. Because most individual technologies are
smaller scale than many of the activities of auto companies (such as designing and developing
entirely new vehicles), it would be expected that the RPE estimate would reflect an upper
bound on the average ICM estimate. The agencies are continuing to study ICMs and the most
appropriate way to apply them, and it is possible revised ICM values may be used in our final
rulemaking. With this in mind, the agencies are presenting a sensitivity analysis reflecting
costs measured using the RPE in place of the ICM and indirect costs estimated independently
in our primary analysis to examine the potential impact of these two approaches on estimated
costs.
While this analysis relies on ICMs to estimate indirect costs, an alternative method of
estimating indirect costs is the RPE factor. The RPE has been used by NHTSA, EPA and
other agencies to account for cost factors not included in available direct cost estimates, which
are derived from cost teardown studies or sometimes provided by manufacturers. The RPE is
the basis for these markups in all DOT safety regulations and in most previous fuel economy
rules. The RPE includes all variable and fixed elements of overhead costs, as well as selling
costs such as vehicle delivery expenses, manufacturer profit, and full dealer markup, and
assumes that the ratio of indirect costs to direct costs is constant for all vehicle changes.
Historically, NHTSA has estimated that the RPE has averaged about 1.5 for the light-duty
motor vehicle industry. The implication of an RPE of 1.5 is that each added $1.00 of variable
cost in materials, labor, and other direct manufacturing costs results in an increase in
consumer prices of $1.50 for any change in vehicles.
NHTSA has estimated the RPE from light-duty vehicle manufacturers' financial
statements over nearly 3 decades, and although its estimated value has varied somewhat year-
to-year, it has generally hovered around a level of 1.5 throughout most of this period. The
2010 NAS report as well as a study by RTI International found that other estimates of the
RPE varied from 1.26 to over 2. In a recent report, The National Academy of Sciences
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(NAS) acknowledged that an ICM approach was preferable but recommended continued use
of the RPE over ICMs until such time as empirical data derived from rigorous estimation
methods is available. The 2010 NAS report recommended using an RPE of 1.5 for
outsourced (supplier manufactured) and 2.0 for in-house (OEM manufactured) technologies
and an RPE of 1.33 for advanced hybrid and electric vehicle technologies.
ICMs typically are significantly lower than RPEs, because they measure changes in
only those elements of overhead and selling-related costs that are directly influenced by
specific technology changes to vehicles. For example, the number of managers might not be
directly proportional to the value of direct costs contained in a vehicle, so that if a regulation
increases the direct costs of manufacturing vehicles, there might be little or no change in the
number of managers. ICMs would thus assume little or no change in that portion of indirect
costs associated with the number of managers - these costs would be allocated only to the
existing base vehicle. By contrast, the RPE reflects the historical overall relationship between
the direct costs to manufacture vehicles and the prices charged for vehicles, which must
compensate manufacturers for both their direct and indirect costs for producing and selling
vehicles. The assumption behind the RPE is that changes in the long-term price of the final
product that accompany increases in direct costs of vehicle manufacturing will continue to
reflect this historical relationship.
Another difference between the RPE and ICM is that ICMs have been derived
separately for different categories of technologies. A relatively simple technology change,
such as switching to a different tire with lower rolling resistance characteristics, would not
influence indirect costs in the same proportion as a more complex change, such as
development of a full hybrid design. ICMs were developed for 3 broad categories of
technology complexities, and are applied separately to fuel economy technologies judged to
fit into each of these categories. This requires determining which of these complexity
categories each technology should be assigned.
There is some level of uncertainty surrounding both the ICM and RPE markup factors.
The ICM estimates used in this proposal group all technologies into three broad categories
and treat them as if individual technologies within each of the three categories (low, medium,
and high complexity) would have the same ratio of indirect costs to direct costs. This
simplification means it is likely that the direct cost for some technologies within a category
will be higher and some lower than the estimate for the category in general. More
importantly, the ICM estimates have not been validated through a direct accounting of actual
indirect costs for individual technologies. Rather, the ICM estimates were developed using
adjustment factors developed in two separate occasions: the first, a consensus process, was
reported in the RTI report; the second, a modified Delphi method, was conducted separately
and reported in an EPA memo. Both these panels were composed of EPA staff members with
previous background in the automobile industry; the memberships of the two panels
overlapped but were not the same. The panels evaluated each element of the industry's RPE
estimates and estimated the degree to which those elements would be expected to change in
proportion to changes in direct manufacturing costs. The method and estimates in the RTI
report were peer reviewed by three industry experts and subsequently by reviewers for the
International Journal of Production Economics. RPEs themselves are inherently difficult to
estimate because the accounting statements of manufacturers do not neatly categorize all cost
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elements as either direct or indirect costs. Hence, each researcher developing an RPE
estimate must apply a certain amount of judgment to the allocation of the costs. Moreover,
RPEs for heavy- and medium-duty trucks and for engine manufacturers are not as well
studied as they are for the light-duty automobile industry. Since empirical estimates of ICMs
are ultimately derived from the same data used to measure RPEs, this affects both measures.
However, the value of RPE has not been measured for specific technologies, or for groups of
specific technologies. Thus applying a single average RPE to any given technology by
definition overstates costs for very simple technologies, or understates them for advanced
technologies.
To highlight the potential differences between the use of ICMs and RPEs to estimate
indirect costs, the agencies conducted an analysis based on the use of average RPEs for each
industry in the place of the ICM and direct fixed cost estimates used in our proposal. Since
most technologies involved in this proposal are low complexity level technologies, the
estimate based on the use of an average RPE likely overstates the costs. The weighted
average RPEs for the truck and engine industries are 1.36 and 1.28 respectively. These values
were substituted for the ICMs and directly estimate indirect costs used in the primary cost
analysis referenced elsewhere in this document. Using the average RPEs, the five model year
cost of $7.7B in the primary analysis increases to $9.3B, an increase of 21 percent. The
agencies request comment accompanied by supporting data on the use of ICMs and RPE
factors to estimate fixed costs.
2.2.2 Learning Effects on Technology Costs
For some of the technologies considered in this analysis, manufacturer learning effects
would be expected to play a role in the actual end costs. The "learning curve" or "experience
curve" describes the reduction in unit production costs as a function of accumulated
production volume. In theory, the cost behavior it describes applies to cumulative production
volume measured at the level of an individual manufacturer, although it is often assumed—as
both agencies have done in past regulatory analyses—to apply at the industry-wide level,
particularly in industries that utilize many common technologies and component supply
sources. Both agencies believe there are indeed many factors that cause costs to decrease
over time. Research in the costs of manufacturing has consistently shown that, as
manufacturers gain experience in production, they are able to apply innovations to simplify
machining and assembly operations, use lower cost materials, and reduce the number or
complexity of component parts. All of these factors allow manufacturers to lower the per-unit
cost of production (i.e., the manufacturing learning curve).
NHTSA and EPA have a detailed description of the learning effect in the 2012-2016
light-duty rule. Most studies of the effect of experience or learning on production costs
appear to assume that cost reductions begin only after some initial volume threshold has been
reached, but not all of these studies specify this threshold volume. The rate at which costs
decline beyond the initial threshold is usually expressed as the percent reduction in average
unit cost that results from each successive doubling of cumulative production volume,
sometimes referred to as the learning rate. Many estimates of experience curves do not
specify a cumulative production volume beyond which cost reductions would no longer occur,
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instead depending on the asymptotic behavior of the effect for learning rates below 100
percent to establish a floor on costs.
In past rulemaking analyses, as noted above, both agencies have used a learning curve
algorithm that applied a learning factor of 20 percent for each doubling of production volume.
NHTSA has used this approach in analyses supporting recent CAFE rules. In its analysis,
EPA has simplified the approach by using an "every two years" based learning progression
rather than a pure production volume progression (i.e., after two years of production it was
assumed that production volumes would have doubled and, therefore, costs would be reduced
by 20 percent).
In the 2012-2016 light-duty rule, the agencies employed an additional learning
algorithm to reflect the volume based learning cost reductions that occur further along on the
learning curve. This additional learning algorithm was termed "time-based" learning simply
as a means of distinguishing this algorithm from the volume-based algorithm mentioned
above, although both of the algorithms reflect the volume based learning curve supported in
the literature.8 The agencies have applied the volume-based algorithm for those technologies
considered to be newer technologies likely to experience rapid cost reductions through
manufacturer learning and the time-based algorithm for those technologies considered to be
mature technologies likely to experience minor cost reductions through manufacturer
learning. As noted above, the volume-based learning algorithm results in 20 percent lower
costs after two full years of implementation (i.e., the 2016 MY costs are 20 percent lower than
the 2014 and 2015 model year costs). Once two volume-based learning steps have occurred
(for technologies having the volume-based learning algorithm applied while time-based
learning would begin in year 2 for technologies having the time-based learning algorithm
applied), time-based learning at 3 percent per year becomes effective for 5 years. Beyond 5
years of time-based learning at 3 percent per year, 5 years of time-based learning at 2 percent
per year, then 5 at 1 percent per year become effective.
Learning effects are applied to most but not all technologies because some of the
expected technologies are already used rather widely in the industry and, presumably,
learning impacts have already occurred. The volume-based learning algorithm was applied
for only a handful of technologies that are considered to be new or emerging technologies.
Most technologies have been considered to be more established given their current use in the
fleet and, hence, the lower time-based learning algorithm has been applied. The learning
algorithms applied to each technology are summarized in Table 2-2.
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Table 2-2 Learning Effect Algorithms Applied to Technologies Used in this Analysis
TECHNOLOGY
Cylinder head improvements
Turbo efficiency improvements
EGR cooler efficiency improvements
Water pump improvements
Oil pump improvements
Fuel pump improvements
Fuel rail improvements
Fuel injector improvements
Piston improvements
Valve train friction reductions
Turbo compounding
Engine friction reduction
Coupled cam phasing
Stoichiometric gasoline direct injection
Low rolling resistance tires
Low rolling resistance tires
Aero (except Aero SmartWay Advanced)
Aero SmartWay Advanced
Weight reduction (via single wide tires and/or
aluminum wheels)
Auxiliary power unit
Air conditioning leakage
APPLIED TO
Engines
Engines
Engines
Engines
Engines
Engines
Engines
Engines
Engines
Engines
Engines
Engines
Engines
Engines
Vocational vehicles
Trucks
Trucks
Trucks
Trucks
Trucks
Trucks
LEARNING
ALGORITHM
Time
Time
Time
Time
Time
Time
Time
Time
Time
Time
Time
Time
Time
Time
Volume
Time
Time
Volume
Time
Time
Time
The learning effects discussed here impact the technology costs considered here in that
those technology costs for which learning effects are considered applicable are changing
throughout the period of implementation and the period following implementation. For
example, some of the technology costs considered in this analysis are taken from the 2012-
2016 light-duty rule and scaled appropriately giving consideration to the heavier weights and
loads in the heavy-duty segment. Many of the costs in the 2012-2016 light-duty rule were
consider "valid" for the 2012 model year. If time based learning were applied to those
technologies, the 2013 cost would be 3 percent lower than the 2012 cost, and the 2014 model
year cost 3 percent lower than the 2013 cost, etc. As a result, the 2014 model year cost
presented in, for example, Section 2.3 would reflect those two years of time based learning
and would not be identical to the 2012 model year cost presented in the 2012-2016 light-duty
rule.
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2.3 Heavy-Duty Pickup Truck and Van Technologies and Costs
2.3.1 Gasoline Engines
The spark ignited engines for Class 2b and 3 vehicles are typically the same as offered
in the light-duty segment. These engines typically range in displacement between five and
eight liters and are either V8 or VI0 configurations.
The engine technologies proposed are based on the technologies described in the Light-
Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy
Standards Joint Technical Support Document.9 Some of the references come from
Technologies and Approaches to Reducing the Fuel Consumption of Medium and Heavy-
Duty Vehicles by The National Academies, March, 2010. These technologies include engine
friction reduction, cam phasing, cylinder deactivation and stoichiometric gas direct injection.
2.3.1.1 Low Friction Lubricants
One of the most basic methods of reducing fuel consumption in both gasoline and
diesel engines is the use of lower viscosity engine lubricants. More advanced multi-viscosity
engine oils are available today with improved performance in a wider temperature band and
with better lubricating properties. This can be accomplished by changes to the oil base stock
(e.g., switching engine lubricants from a Group I base oils to lower-friction, lower viscosity
Group III synthetic) and through changes to lubricant additive packages (e.g., friction
modifiers and viscosity improvers). The use of 5W-30 motor oil is now widespread and auto
manufacturers are introducing the use of even lower viscosity oils, such as 5W-20 and OW-20,
to improve cold-flow properties and reduce cold start friction. However, in some cases,
changes to the crankshaft, rod and main bearings and changes to the mechanical tolerances of
engine components may be required. In all cases, durability testing would be required to
ensure that durability is not compromised. The shift to lower viscosity and lower friction
lubricants will also improve the effectiveness of valvetrain technologies such as cylinder
deactivation, which rely on a minimum oil temperature (viscosity) for operation.
Based on 2012-2016 Light-duty final rule, and previously-received confidential
manufacturer data, NHTSA and EPA estimated the effectiveness of low friction lubricants to
be between 0 to 1 percent.
In the 2012-2016 light-duty FRM, the agencies estimated the cost of moving to low
friction lubricants at $3 per vehicle (2007$). That estimate included a markup of 1.11 for a
low complexity technology. For Class 2b and 3, we are using the same base estimate but have
marked it up to 2008 dollars using the GDP price deflator and have used a markup of 1.17 for
a low complexity technology to arrive at a value of $4 per vehicle. As in the light-duty rule,
learning effects are not applied to costs for this technology and, as such, this estimate applies
to all model years.10'11
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2.3.1.2 Engine Friction Reduction
Manufacturers can reduce friction and improve fuel consumption by improving the
design of engine components and subsystems. Approximately 10 percent of the energy
consumed by a vehicle is lost to friction, and just over half is due to frictional losses within
the engine. Examples include improvements in low-tension piston rings, piston skirt design,
roller cam followers, improved crankshaft design and bearings, material coatings, material
substitution, more optimal thermal management, and piston and cylinder surface treatments.
Additionally, as computer-aided modeling software continues to improve, more opportunities
for evolutionary friction reductions may become available.
All reciprocating and rotating components in the engine are potential candidates for
friction reduction, and minute improvements in several components can add up to a
measurable fuel economy improvement. The 2012-2016 LD rule, 2010 NAS, NESCCAF and
EEA reports as well as confidential manufacturer data suggested a range of effectiveness for
engine friction reduction to be between 1 to 3 percent. NHTSA and EPA continue to believe
that this range is accurate.
Consistent with the 2012-2016 light-duty FRM, the agencies estimate the cost of this
technology at $14 per cylinder compliance cost (2008$), including the low complexity ICM
markup value of 1.17. Learning impacts are not applied to the costs of this technology and, as
such, this estimate applies to all model years. This cost is multiplied by the number of engine
cylinders.
2.3.1.3 Coupled Cam Phasing (CCP)
Valvetrains with coupled (or coordinated) cam phasing can modify the timing of both
the inlet valves and the exhaust valves an equal amount by phasing the camshaft of an
overhead valve (OHV) engine. For overhead valve (OHV) engines, which have only one
camshaft to actuate both inlet and exhaust valves, CCP is the only VVT implementation
option available and requires only one cam phaser.
Consistent with the 2012-2016 Light-Duty final rule, NHTSA and EPA estimate the
effectiveness of CCP to be between 1 to 4 percent.
Consistent with the 2012-2016 Light-Duty final rule, NHTSA and EPA estimate the
cost of a cam phaser at $46 (2008$) in the 2014MY. This estimate includes a low complexity
ICM of 1.17 and time based learning. All engines in the Class 2b&3 category use over-head
valve engines (OHV) and, as such, would require only one cam phaser for coupled cam
phasing.
2.3.1.4 Cylinder Deactivation (DEAC)
In conventional spark-ignited engines throttling the airflow controls engine torque
output. At partial loads, efficiency can be improved by using cylinder deactivation instead of
throttling. Cylinder deactivation (DEAC) can improve engine efficiency by disabling or
deactivating (usually) half of the cylinders when the load is less than half of the engine's total
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torque capability - the valves are kept closed, and no fuel is injected - as a result, the trapped
air within the deactivated cylinders is simply compressed and expanded as an air spring, with
reduced friction and heat losses. The active cylinders combust at almost double the load
required if all of the cylinders were operating. Pumping losses are significantly reduced as
long as the engine is operated in this "part-cylinder" mode.
Cylinder deactivation control strategy relies on setting maximum manifold absolute
pressures or predicted torque within which it can deactivate the cylinders. Noise and
vibration issues reduce the operating range to which cylinder deactivation is allowed,
although manufacturers are exploring vehicle changes that enable increasing the amount of
time that cylinder deactivation might be suitable. Some manufacturers may choose to adopt
active engine mounts and/or active noise cancellations systems to address NVH concerns and
to allow a greater operating range of activation.
Effectiveness improvements scale roughly with engine displacement-to-vehicle weight
ratio: the higher displacement-to-weight vehicles, operating at lower relative loads for normal
driving, have the potential to operate in part-cylinder mode more frequently.
NHTSA and EPA adjusted the 2012-2016 Light-Duty final rule estimates using
updated power to weight ratings of heavy-duty trucks and confidential business information
and confirmed a range of 3 to 4 percent for these vehicles.
Consistent with the 2012-2016 light-duty FRM, NHTSA and EPA have estimated the
cost of cylinder deactivation at $193 for the 2014MY (2008$). This estimate includes a low
complexity ICM of 1.17 and time based learning.
2.3.1.5 Stoichiometric Gasoline Direct Injection (SGDI)
Stoichiometric gasoline direct injection (SGDI) engines inject fuel at high pressure
directly into the combustion chamber (rather than the intake port in port fuel injection). SGDI
requires changes to the injector design, an additional high pressure fuel pump, new fuel rails
to handle the higher fuel pressures and changes to the cylinder head and piston crown design.
Direct injection of the fuel into the cylinder improves cooling of the air/fuel charge within the
cylinder, which allows for higher compression ratios and increased thermodynamic efficiency
without the onset of combustion knock. Recent injector design advances, improved electronic
engine management systems and the introduction of multiple injection events per cylinder
firing cycle promote better mixing of the air and fuel, enhance combustion rates, increase
residual exhaust gas tolerance and improve cold start emissions. SGDI engines achieve
higher power density and match well with other technologies, such as boosting and variable
valvetrain designs.
Several manufacturers have recently introduced vehicles with SGDI engines,
including GM and Ford and have announced their plans to increase dramatically the number
of SGDI engines in their portfolios.
The 2012-2016 Light-Duty rule estimate the range of effectiveness to be from 1 to 2
percent for SGDI. NHTSA and EPA reviewed this estimate for purposes of the NPRM, and
continue to find it accurate.
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The NHTSA and EPA cost estimates for SGDI take into account the changes required
to the engine hardware, engine electronic controls, ancillary and Noise Vibration and
Harshness (NVH) mitigation systems. Through contacts with industry NVH suppliers, and
manufacturer press releases, the agencies believe that the NVH treatments will be limited to
the mitigation of fuel system noise, specifically from the injectors and the fuel lines.
Consistent with the 2012-2016 light-duty rule, the agencies estimate the cost of conversion to
SGDI on a V8 engine at $395 (2008$) for the 2014MY. This estimate includes a low
complexity ICM of 1.17 and time based learning.
2.3.2 Diesel Engines
Diesel engines in this class of vehicle have emissions characteristics that present
challenges to meeting federal Tier 2 NOX emissions standards. It is a significant systems-
engineering challenge to maintain the fuel consumption advantage of the diesel engine while
meeting U.S. emissions regulations. Fuel consumption can be negatively impacted by
emissions reduction strategies depending on the combination of strategies employed.
Emission compliance strategies for diesel vehicles sold in the U.S. are expected to include a
combination of improvements of combustion, air handling system, aftertreatment, and
advanced system control optimization. These emission control strategies are being introduced
on Tier 2 light-duty diesel vehicles today
The engine technologies proposed are based on the technologies described in the Light-
Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy
19
Standards Joint Technical Support Document. Some of reference comes from
Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-
Duty Vehicles by The National Academies, March, 2010. Several key advances in diesel
technology have made it possible to reduce missions coming from the engine prior to
aftertreatment. These technologies include, engine friction and parasitic loss reduction,
improved fuel systems (higher injection pressure and multiple-injection capability), advanced
controls and sensors to optimize combustion and emissions performance, higher EGR levels
and EGR cooling to reduce NOx, and advanced turbocharging systems.
2.3.2.1 Low Friction Lubricants
Consistent with the discussion above for gasoline engines (see Section 2.3.1.1), the
agencies are expecting some engine changes to accommodate low friction lubricants. Based
on 2012-2016 Light-duty final rule, and previously-received confidential manufacturer data,
NHTSA and EPA estimated the effectiveness of low friction lubricants to be between 0 to 1
percent.
In the 2012-2016 light-duty FRM, the agencies estimated the cost of moving to low
friction lubricants at $3 per vehicle (2007$). That estimate included a markup of 1.11 for a
low complexity technology. For Class 2b and 3, we are using the same base estimate but have
marked it up to 2008 dollars using the GDP price deflator and have used a markup of 1.17 for
a low complexity technology to arrive at a value of $4 per vehicle. As in the light-duty rule,
learning effects are not applied to costs for this technology and, as such, this estimate applies
to all model years.13'14
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Regulatory Impact Analysis
2.3.2.2 Engine Friction Reduction
Engine Friction Reduction: Reduced friction in bearings, valve trains, and the piston-
to-liner interface will improve efficiency. Friction reduction opportunities in the engine
valve train and at its roller/tappet interfaces exist for several production engines. In virtually
all production engines, the piston at its skirt/cylinder wall interface, wrist pin and oil
ring/cylinder wall interface offer opportunities for friction reduction. Use of more advanced
oil lubricant that could be available for production in the future can also play a key role in
reducing friction. Any friction reduction must be carefully developed to avoid issues with
durability or performance capability. Estimations of fuel consumption improvements due to
reduced friction range from 0 percent to 2 percent.15
Consistent with the cost estimated for gasoline engines, the agencies estimate the cost
of engine friction reduction at $14 per cylinder compliance cost (2008$), including the low
complexity ICM of 1.17, for a MY 2014 vehicle (learning effects are not applied to engine
friction reduction). This cost is multiplied by the number of engine cylinders.
2.3.2.3 Combustion and Fuel Injection System Optimization
More flexible fuel injection capability with higher injection pressure provides more
opportunities to improve engine fuel economy, while maintaining the same emission level.
Combustion system optimization features system level integration and match, which includes
piston bowl, injector tip and the number of holes, and intake swirl ratio. Cummins reports 9.1
percent improvement in fuel consumption as opposed to 2007 baseline while meeting Tier2
Bin 5 emissions when the combustion and fuel injection system are integrated with other
technologies, such as advanced and integrated aftertreatment technology, and advanced air
handling system).16 Translating this improvement with 2010 baseline engine, this could result
in 4-6 percent improvement assuming that 2010 baseline engine has 3-5 percent advantage in
fuel economy over 2007 engine baseline.
The cost for this technology includes costs associated with low temperature exhaust
gas recirculation (see Section 2.3.2.4), improved turbochargers (see Section 2.3.2.5) and
improvements to other systems and components. These costs are considered collectively in
our costing analysis and termed "diesel engine improvements." The agencies have estimated
the cost of diesel engine improvements at $147 based on the cost estimates for several
individual technologies presented in Table 2-8 for light HD engines. Specifically, the direct
manufacturing costs we have estimated are: improved cylinder head, $9; turbo efficiency
improvements, $16; EGR cooler improvements, $3; higher pressure fuel rail, $10; improved
fuel injectors, $13; improved pistons, $2; and reduced valve train friction, $94. All values
are in 2008 dollars and are applicable in the 2014MY. Applying a low complexity ICM of
1.17 results in a cost of $172 (2008$) applicable in the 2014MY. We consider time based
learning to be appropriate for these technologies.
2.3.2.4 Low Temperature Exhaust Gas Recirculation
Low temperature exhaust gas recirculation could be one of options to improve engine
performance. Most medium vehicle diesel engines sold in the U.S. market today use cooled
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EGR, in which part of the exhaust gas is routed through a cooler (rejecting energy to the
engine coolant) before being returned to the engine intake manifold. EGR is a technology
employed to reduce peak combustion temperatures and thus NO*. Low-temperature EGR uses
a larger or secondary EGR cooler to achieve lower intake charge temperatures, which tend to
further reduce NO* formation. Low-temperature EGR can allow changes such as more
advanced injection timing that will increase engine efficiency slightly more than 1 percent
(NESCCAF/ICCT, 2009, p. 62). Because low-temperature EGR reduces the engine's exhaust
temperature, it may not be compatible with exhaust energy recovery systems such as
turbocompound or a bottoming cycle.
The agencies' cost estimate for this technology is discussed in Section 2.3.2.3.
2.3.2.5 Turbocharger Technology
Compact two stage turbochargers can increase the boost level with wider operation
range, thus improving engine thermal efficiency. Ford's new developed 6.7L Scorpion engine
features twin-compressor turbocharger. Cummins is also developing its own two stage
turbochargers.1? It is expected that this type of technology will continue to be improved by
better matching with system and developing higher compressor and turbine efficiency.
The agencies' cost estimate for this technology is discussed in Section 2.3.2.3.
2.3.2.6 Reduction of Parasitic Loads
Accessories that are traditionally gear or belt driven by a vehicle's engine can be
optimized and/or converted to electric power. Examples include the engine water pump, oil
pump, fuel injection pump, air compressor, power-steering pump, cooling fans, and the
vehicle's air-conditioning system. Optimization and improved pressure regulation may
significantly reduce the parasitic load of the water, air and fuel pumps. Electrification may
result in a reduction in power demand, because electrically powered accessories (such as the
air compressor or power steering) operate only when needed if they are electrically powered,
but they impose a parasitic demand all the time if they are engine driven. In other cases, such
as cooling fans or an engine's water pump, electric power allows the accessory to run at
speeds independent of engine speed, which can reduce power consumption. Electrification of
accessories can individually improve fuel consumption, but as a package on a hybrid vehicle
it is estimated that 3 to 5 percent fuel consumption reduction is possibles The TIAX [2009,
pg. 3-5] study used 2 to 4 percent fuel consumption improvement for accessory electrification,
with the understanding that electrification of accessories will have more effect in short-
haul/urban applications and less benefit in line-haul applications.
Consistent with the 2012-2016 light-duty rule (where this technology was referred to
as improved accessories), the agencies estimate the cost for this technology at $88 (2008$) for
a 2014MY vehicle. This estimate includes a low complexity ICM of 1.17 and time based
learning.
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Regulatory Impact Analysis
2.3.2.7 Improved Aftertreatment Efficiency and Effectiveness
Improved SCR Conversion Efficiency: Selective Catalytic Reduction (SCR) systems
are used by several manufacturers to control NOX emissions. 2010 fuel consumption was
reduced 3 to 4 percent when compared to 2009, depending upon the manufacturer [2009,
TIAX]. Additional improvements of 3 to 5 percent relative to 2010 may be reasonably
expected as system effectiveness increases and accumulated knowledge is applied in
calibration. Additionally, as SCR system effectiveness is improved, Diesel paniculate filters
(DPF) may be better optimized to reduced particulate loading (ability to run at higher engine
out NOX), reducing the associated pressure drop associated with their presence in the exhaust
system. Such DPF changes may result in a 1.0 - 1.5 percent fuel consumption reduction
[TIAX, 2009, pg. 4-10].
The agencies have estimated the cost of this technology at $25 for each percentage
improvement in fuel consumption. This estimate is based on the agencies' belief that this
technology is, in fact, a very cost effective approach to improving fuel consumption. As such,
$25 per percent improvement is considered a reasonable cost. This cost would cover the
engineering and test cell related costs necessary to develop and implement the improved
control strategies that would allow for the improvements in fuel consumption. Importantly,
the engineering work involved would be expected to result in cost savings to the
aftertreatment and control hardware (lower platinum group metal (PGM) loadings, lower
reductant dosing rates, etc.). Those savings are considered to be included in the $25 per
percent estimate described here. Given the average 4 percent expected improvement in fuel
consumption results in an estimated cost of $110 (2008$) for a 2014MY vehicle. This
estimate includes a low complexity ICM of 1.17 and time based learning from 2012 forward.
2.3.3 Drive Train
NHTSA and EPA have also reviewed the transmission technology estimates used in
the 2012-2016 light-duty final rule. In doing so, NHTSA and EPA considered or
reconsidered all available sources and updated the estimates as appropriate. The section
below describes each of the transmission technologies considered for this rulemaking.
2.3.3.1 Improved Automatic Transmission Control (IATC) (Aggressive Shift Logic and
Early Torque Converter Lockup)
Calibrating the transmission shift schedule to upshift earlier and quicker, and to lock-
up or partially lock-up the torque converter under a broader range of operating conditions can
reduce fuel consumption and CC>2 emissions. However, this operation can result in a
perceptible degradation in noise, vibration, and harshness (NVH). The degree to which NVH
can be degraded before it becomes noticeable to the driver is strongly influenced by
characteristics of the vehicle, and although it is somewhat subjective, it always places a limit
on how much fuel consumption can be improved by transmission control changes. Given that
the Aggressive Shift Logic and Early Torque Converter Lockup are best optimized
simultaneously due to the fact that adding both of them primarily requires only minor
modifications to the transmission or calibration software, these two technologies are
combined in the modeling.
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2.3.3.2 Aggressive Shift Logic
During operation, an automatic transmission's controller manages the operation of the
transmission by scheduling the upshift or downshift, and locking or allowing the torque
converter to slip based on a preprogrammed shift schedule. The shift schedule contains a
number of lookup table functions, which define the shift points and torque converter lockup
based on vehicle speed and throttle position, and other parameters such as temperature.
Aggressive shift logic (ASL) can be employed in such a way as to maximize fuel efficiency
by modifying the shift schedule to upshift earlier and inhibit downshifts under some
conditions, which reduces engine pumping losses and engine friction. The application of this
technology does require a manufacturer to confirm that drivability, durability, and NVH are
not significantly degraded.
We consider this technology to be present in the baseline, 6-speed automatic
transmissions in the majority of Class 2b and 3 trucks in the 2010 model year timeframe.
2.3.3.3 Early Torque Converter Lockup
A torque converter is a fluid coupling located between the engine and transmission in
vehicles with automatic transmissions and continuously-variable transmissions (CVT). This
fluid coupling allows for slip so the engine can run while the vehicle is idling in gear (as at a
stop light), provides for smoothness of the powertrain, and also provides for torque
multiplication during acceleration, and especially launch. During light acceleration and
cruising, the inherent slip in a torque converter causes increased fuel consumption, so modern
automatic transmissions utilize a clutch in the torque converter to lock it and prevent this
slippage. Fuel consumption can be further reduced by locking up the torque converter at
lower vehicle speeds, provided there is sufficient power to propel the vehicle, and noise and
vibration are not excessive. If the torque converter cannot be fully locked up for maximum
efficiency, a partial lockup strategy can be employed to reduce slippage. Early torque
converter lockup is applicable to all vehicle types with automatic transmissions. Some torque
converters will require upgraded clutch materials to withstand additional loading and the
slipping conditions during partial lock-up. As with aggressive shift logic, confirmation of
acceptable drivability, performance, durability and NVH characteristics is required to
successfully implement this technology.
We consider this technology to be present in the baseline, 6-speed automatic
transmissions in the majority of Class 2b and 3 trucks in the 2010 model year timeframe.
2.3.3.4 Automatic 6- and 8-Speed Transmissions
Manufacturers can also choose to replace 4- and 5-speed transmission with 6- or 8-
speed automatic transmissions. Additional ratios allow for further optimization of engine
operation over a wider range of conditions, but this is subject to diminishing returns as the
number of speeds increases. As additional planetary gear sets are added (which may be
necessary in some cases to achieve the higher number of ratios), additional weight and friction
are introduced. Also, the additional shifting of such a transmission can be perceived as
bothersome to some consumers, so manufacturers need to develop strategies for smooth
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Regulatory Impact Analysis
shifts. Some manufacturers are replacing 4- and 5-speed automatics with 6-speed automatics,
and 7- and 8-speed automatics have also entered production, albeit in lower-volume
applications in luxury and performance oriented cars.
As discussed in the 2012-2016 light-duty final rule, confidential manufacturer data
projected that 6-speed transmissions could incrementally reduce fuel consumption by 0 to 5
percent from a baseline 4-speed automatic transmission, while an 8-speed transmission could
incrementally reduce fuel consumption by up to 6 percent from a baseline 4-speed automatic
transmission. GM has publicly claimed a fuel economy improvement of up to 4 percent for
its new 6-speed automatic transmissions.
NHTSA and EPA reviewed and revised these effectiveness estimates based on usage
and testing methods for Class 2b and 3 vehicles along with confidential business information.
When combined with IATC, the agencies estimate the effectiveness for a conversion from a 4
to a 6-speed transmission to be 5.3 percent and a conversion from a 6 to 8-speed transmission
to be 1.7 percent for the NPRM.
As for costs, the agencies have considered the recent study conducted by NAS (NAS
2010) which showed an incremental cost of $210 for an 8 speed automatic transmission
relative to a 6 speed automatic transmission (the baseline technology for 2010MY Class 2b &
3 pickups and vans). Considering this to be a valid cost for 2012MY and applying a low
complexity ICM of 1.17 results in a cost of $246 in 2012. Considering time based learning to
be appropriate for automatic transmissions and applying two years of time based learning
results in a 2014MY cost of $231 (2008$). This technology is considered applicable to both
gasoline and diesel trucks and vans.
2.3.3.5 Electric Power Steering/Electro-hydraulic Power Steering (EPS/EHPS)
Electric power steering (EPS) or Electrohydraulic power steering (EHPS) provides a
potential reduction in CO2 emissions and fuel consumption over hydraulic power steering
because of reduced overall accessory loads. This eliminates the parasitic losses associated
with belt-driven power steering pumps which consistently draw load from the engine to pump
hydraulic fluid through the steering actuation systems even when the wheels are not being
turned. EPS is an enabler for all vehicle hybridization technologies since it provides power
steering when the engine is off. EPS may be implemented on most vehicles with a standard
12V system. Some heavier vehicles may require a higher voltage system which may add cost
and complexity.
The 2010 light-duty final rule estimated a 1 to 2 percent effectiveness based on the
2002 NAS report, a Sierra Research report, and confidential manufacturer data. NHTSA and
EPA reviewed these effectiveness estimates and found them to be accurate, thus they have
been retained for this final rule.
NHTSA and EPA adjusted the EPS cost for the current rulemaking based on a review
of the specification of the system. Adjustments were made to include potentially higher
voltage or heavier duty system operation for Class 2b and 3. Accordingly, higher costs were
estimated for systems with higher capability. After accounting for the differences in system
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capability and applying the ICM markup of low complexity technology of 1.17, the estimated
costs for this proposal are $108 for a MY 2014 truck or van (2008$). As EPS systems are in
widespread usage today, time-based learning is deemed applicable. EHPS systems are
considered to be of equal cost and both are considered applicable to gasoline and diesel
engines.
2.3.4 Aerodynamics
Aerodynamic drag is an important aspect of the power requirements for Class 2b and 3
trucks. Because aerodynamic drag is a function of the cube of vehicle speed, small changes in
the aerodynamics of a Class 2b and 3 can reduce drag, fuel consumption, and GHG emissions.
Some of the opportunities to reduce aerodynamic drag in Class 2b and 3 vehicles are similar
to those in Class 1 and 2 (i.e., light-duty) vehicles. In general, these transferable features make
the cab shape more aerodynamic by streamlining the airflow over the bumper, grill,
windshield, sides, and roof. Class 2b and 3 vehicles may also borrow from light-duty vehicles
certain drag reducing accessories (e.g., streamlined mirrors, operator steps, and sun visors).
The great variety of applications for Class 2b and 3 trucks result in a wide range of
operational speed profiles (i.e., in-use drive cycles) and functional requirements (e.g., shuttle
buses that must be tall enough for standing passengers, trucks that must have racks for
ladders). This variety makes it challenging to develop aerodynamic solutions that consider
the entire vehicle.
Consistent with the 2012-2016 light-duty rule, the agencies have estimated the cost for
this technology at $54 (2008$) including a low complexity ICM of 1.17. This cost is
applicable in the 2014 model year to both gasoline and diesel trucks and vans.
2.3.5 Tires
Typically, tires used on Class 2b/3 vehicles are not designed specifically for the
vehicle. These tires are designed for broader use and no single parameter is optimized.
Similar to vocational vehicles, the market has not demanded tires with improved rolling
resistance; therefore, manufacturers have not traditionally designed tires with low rolling
resistance for Class 2b/3 vehicles. EPA believes that a regulatory program that incentivizes
the optimization of tire rolling resistance, traction and durability can bring about GHG
emission reductions from this segment.
Based on the 2012-2016 Light-duty final rule and the 2010 NAS report, the agencies
have estimated the cost for low rolling resistance tires to be $6 per Class 2b truck or van, and
$9 per Class 3 truck or van.18 The higher cost for the Class 3 trucks and vans is due to the
predominant use of dual rear tires and, thus, 6 tires per truck. Due to the commodity-based
nature of this technology, cost learning is not applied. This technology is considered
applicable to both gasoline and diesel.
2.4 Heavy-Duty Engines
The proposed regulatory structure for heavy-duty engines separates the compression
ignition (or "diesel") engines into three regulatory subcategories and from spark ignition (or
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Regulatory Impact Analysis
"gasoline") engines into a single regulatory subcategory. Therefore, the subsequent
discussion will assess each type of engine separately.
The Light- and Heavy-Duty Diesel engines typically range between 4.7 and 6.7 liters
displacement, the Medium-Heavy-Duty Diesel engines typically have some overlap in
displacement with the Light-Heavy-Duty Diesel engines and range between 6.7 and 9.3 liters.
The Heavy-Duty Diesel engines typically are represented by engines between 10.8 and 16
liters. The heavy-duty gasoline engines have ranged in the past between 4.8 and 8.1 liters.
2.4.1 Spark Ignition Engines
Spark ignition engines are certified for the heavy-duty market. These engines
typically range in displacement between five and eight liters and are either V8 or VI0
configurations. As found in the 2010 NAS study, most are either V8 or VI0 engines with
port fuel injection, naturally aspirated with fixed valves. In the recent past, the primary
producers of the gasoline engines were limited to Ford and General Motors. The engines sold
separately, which require an engine certificate in lieu of a chassis certificate, are the same as
or very similar to the engines used in the pickup truck and vans. Therefore, NHTSA and EPA
developed the baseline, list of engine technologies, and standards to reflect this commonality.
2.4.1.1 Baseline SI Engine COi and Fuel Consumption
Similar to the gasoline engine used as the baseline in the Light-Duty GHG rule (an
assumption not questioned in the comments to that rulemaking), the agencies assumed the
baseline engine in this segment to be a naturally aspirated, single overhead valve V8 engine.
The following discussion of effectiveness is generally in comparison to 2010 baseline engine
performance.
NHTSA and EPA developed the baseline fuel consumption and CC>2 emissions for the
gasoline engines from manufacturer reported CC>2 values used in the certification of non-
GHG pollutants. The baseline engine for the analysis was developed to represent a 2011
model year engine, because this is the most current information available. The average CO2
performance of the heavy-duty gasoline engines was 660 g/bhp-hour, which will be used as a
baseline.
2.4.1.2 Gasoline Engine Technologies
The engine technologies projected for the gasoline heavy-duty engines are based on
the technologies used in the Light-Duty Vehicle Greenhouse Gas Emission Standards and
Corporate Average Fuel Economy Standards Joint Technical Support Document.19 The
effectiveness of the technology packages were evaluated using the EPA Lumped Parameter
90
model HD Version 1.0.0.1. The HD version of the Lumped Parameter model includes a
subset of the technologies included in the Large Pickup Truck version of the Light-Duty
rulemaking to recognize that some technologies will have limited effectiveness due to the
higher operating weights of these trucks. The HD Lumped Parameter model also has reduced
the effectiveness of several of the individual technologies again to recognize the higher test
weights used in regulatory programs.
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2.4.1.2.1 Engine Friction Reduction
In addition to low friction lubricants, manufacturers can also reduce friction and
improve fuel consumption by improving the design of engine components and subsystems.
Examples include improvements in low-tension piston rings, piston skirt design, roller cam
followers, improved crankshaft design and bearings, material coatings, material substitution,
more optimal thermal management, and piston and cylinder surface treatments. Additionally,
as computer-aided modeling software continues to improve, more opportunities for
evolutionary friction reductions may become available. All reciprocating and rotating
components in the engine are potential candidates for friction reduction, and minute
improvements in several components can add up to a measurable fuel economy improvement.
The 2012-2016 light-duty rule, 2010 NAS, NESCCAF and EEA reports as well as
confidential manufacturer data suggested a range of effectiveness for engine friction reduction
to be between 1 to 3 percent. NHTSA and EPA continue to believe that this range is accurate.
NHTSA and EPA believe that the cost estimate is closer to the lower end of the model
year (MY) 2011 CAFE final rule range and thus for this rulemaking is proposing $9 per
cylinder compliance cost (2008$), plus a low complexity Indirect Cost Multiplier (ICM)
markup value of 1.17, for a MY 2016 engine (learning effects are not applied to engine
friction reduction). This cost is multiplied by the eight cylinders resulting in a cost of $88
(2008$) per engine for this technology.
2.4.1.2.2 Coupled Cam Phasing
Valvetrains with coupled (or coordinated) cam phasing (CCP) can modify the timing
of both the inlet valves and the exhaust valves an equal amount by phasing the camshaft of a
single overhead cam (SOHC) engine or an overhead valve (OHV) engine. For overhead cam
engines, this requires the addition of a cam phaser on each bank of the engine so SOHC V-
engines have two cam phasers. For overhead valve (OHV) engines, which have only one
camshaft to actuate both inlet and exhaust valves, CCP is the only variable valve timing
(VVT) implementation option available and requires only one cam phaser. Based on 2010
Light-Duty final rule, previously-received confidential manufacturer data, and the NESCCAF
report, NHTSA and EPA estimated the effectiveness of CCP to be between 1 to 4 percent.
NHTSA and EPA reviewed this estimate for purposes of the NPRM, and continue to find it
accurate.
Consistent with the 2010 2012-2016 Light-Duty final rule, NHTSA and EPA estimate
the cost of a cam phaser at $46 (2008$) in the 2014MY. This estimate includes a low
complexity ICM of 1.17. With two years of time based learning this cost becomes $43
(2008$) in the 2016MY. All heavy-duty gasoline loose engines are over-head valve engines
(OHV) and, as such, would require only one cam phaser for coupled cam phasing.
2.4.1.2.3 Cylinder Deactivation
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In conventional spark-ignited engines throttling the airflow controls engine torque
output. At partial loads, efficiency can be improved by using cylinder deactivation instead of
throttling. Cylinder deactivation (DEAC) can improve engine efficiency by disabling or
deactivating (usually) half of the cylinders when the load is less than half of the engine's total
torque capability - the valves are kept closed, and no fuel is injected - as a result, the trapped
air within the deactivated cylinders is simply compressed and expanded as an air spring, with
reduced friction and heat losses. The active cylinders combust at almost double the load
required if all of the cylinders were operating. Pumping losses are significantly reduced as
long as the engine is operated in this "part cylinder" mode.
Cylinder deactivation control strategy relies on setting maximum manifold absolute
pressures or predicted torque within which it can deactivate the cylinders. Noise vibration and
harshness (NVH) issues reduce the operating range to which cylinder deactivation is allowed,
although manufacturers are exploring vehicle changes that enable increasing the amount of
time that cylinder deactivation might be suitable. Some manufacturers may choose to adopt
active engine mounts and/or active noise cancellations systems to address NVH concerns and
to allow a greater operating range of activation. Cylinder deactivation has seen a recent
resurgence thanks to better valvetrain designs and engine controls. General Motors and
Chrysler Group have incorporated cylinder deactivation across a substantial portion of their
V8-powered lineups.
Effectiveness improvements scale roughly with engine displacement-to-vehicle weight
ratio: the higher displacement-to-weight vehicles, operating at lower relative loads for normal
driving, have the potential to operate in part-cylinder mode more frequently. NHTSA and
EPA adjusted the 2010 light-duty final rule estimates using updated power to weight ratings
of heavy-duty trucks and confidential business information and confirmed a range of 3 to 4
percent for these vehicles.
Consistent with the 2012-2016 light-duty FRM, NHTSA and EPA have estimated the
cost of cylinder deactivation at $193 for the 2014MY (2008$). This estimate includes a low
complexity ICM of 1.17. With two years of time based learning, this cost becomes $181
(2008$) in the 2016MY. This technology was not considered to be a necessary technology to
achieve the proposed standards and thus has not been included in the package cost.
2.4.1.2.4 Stoichiometric gasoline direct injection
SGDI engines inject fuel at high pressure directly into the combustion chamber
(rather than the intake port in port fuel injection). SGDI requires changes to the injector
design, an additional high pressure fuel pump, new fuel rails to handle the higher fuel
pressures and changes to the cylinder head and piston crown design. Direct injection of the
fuel into the cylinder improves cooling of the air/fuel charge within the cylinder, which allows
for higher compression ratios and increased thermodynamic efficiency without the onset of
combustion knock. Recent injector design advances, improved electronic engine management
systems and the introduction of multiple injection events per cylinder firing cycle promote
better mixing of the air and fuel, enhance combustion rates, increase residual exhaust gas
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tolerance and improve cold start emissions. SGDI engines achieve higher power density and
match well with other technologies, such as boosting and variable valvetrain designs. NHTSA
and EPA estimate the range of 1 to 2 percent improvement for SGDI.
The NHTSA and EPA cost estimates for SGDI take into account the changes required
to the engine hardware, engine electronic controls, ancillary and NVH mitigation systems.
Through contacts with industry NVH suppliers, and manufacturer press releases, the agencies
believe that the NVH treatments will be limited to the mitigation of fuel system noise,
specifically from the injectors and the fuel lines.
The NHTSA and EPA cost estimates for SGDI take into account the changes required
to the engine hardware, engine electronic controls, ancillary and Noise Vibration and
Harshness (NVH) mitigation systems. Through contacts with industry NVH suppliers, and
manufacturer press releases, the agencies believe that the NVH treatments will be limited to
the mitigation of fuel system noise, specifically from the injectors and the fuel lines.
Consistent with the 2012-2016 light-duty rule, the agencies estimate the cost of conversion to
SGDI on a V8 engine at $395 (2008$) for the 2014MY. This estimate includes a low
complexity ICM of 1.17. With two years of time based learning, this cost becomes $372
(2008$)inthe2016MY.
2.4.1.3 Derivation of Gasoline Engine Standard
The average CC>2 performance of the two heavy-duty gasoline engines certified for
2010 and 2011 model years was 660 g CO2/bhp-hour. The HD Lumped Parameter model
analysis projects that the package of the three technologies (friction reduction, closed couple
cam phasing, and stoichiometric direct injection) could reduce CC>2 emissions and fuel
consumption by 5 percent. Therefore, the agencies are proposing to set the standard in 2016
model year at 627 g CO2/bhp-hr.
2.4.1.4 SI Engine Technology Cost
As shown in Table 2-3, the overall projected engine package cost for a 2016 model
year engine is $504 (2008$).
Table 2-3 Estimated 2016MY Costs for a Spark-Ignition HD Engine (2008 dollars)
Engine Friction Reduction
Coupled Cam Phasing
Stoichiometric Gas Direct Injection
Total
DIRECT MFG
COST
$76
$37
$318
$431
ICM
1.17
1.17
1.17
MARKED UP
COSTS
$88
$43
$372
$504
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Regulatory Impact Analysis
2.4.2 Diesel Engines
2.4.2.1 Baseline Engines
The agencies developed the baseline diesel engine as a 2010 model year engine with
an aftertreatment system which meets EPA's 0.2 grams of NOx/bhp-hr standard with a
selective catalytic reduction (SCR) system along with EGR and meets the PM emissions
standard with a diesel particulate filter (DPF) with active regeneration. The engine is
turbocharged with a variable geometry turbocharger. The following discussion of
technologies describes improvements over the 2010 model year baseline engine performance,
unless otherwise noted.
The CC>2 performance over the FTP for the baseline engines were developed through
manufacturer reporting of CC>2 in their non-GHG certification applications for 2010 model
year. This data was carefully considered to insure that the baseline represented an engine
meeting the 0.2 g/bhp-hr NOx standard. For those engines that were not at this NOx level or
higher, then the agencies derived a CO2 correction factor to bring them to a 0.2 g/bhp-hr NOx
emissions. The CC>2 correction factor is derived based on available experimental data
obtained from manufacturers and public literature. The agencies then sales-weighted the CO2
performance to derive a baseline CC>2 performance for each engine subcategory.
In order to establish baseline SET performance for the Heavy Heavy-Duty and
Medium Heavy-Duty Diesel Engines, several sources were considered. Some engine
manufacturers provided the agencies SET modal results or fuel consumption maps to
represent their 2009 model year engine fuel consumption performance. As a supplement to
this, complete engine map CO2 data (including SET modes) acquired in EPA test cells were
also considered. The pre-2010 maps are subsequently adjusted to represent 2010 model year
engine maps by using predefined technologies including SCR and other advanced systems
that are being used in current 2010 production.
In summary, the baseline CC>2 performance for each diesel engine category is included
in Table 2-4.
Table 2-4: Baseline CO2 Performance (g/bhp-hr)
ILHDD - FTP
630
MHDD - FTP
630
HHDD - FTP
584
HHDD - SET
490
The agencies used the baseline engine to assess the potential of each of the following
technologies.
2.4.2.2 Combustion System Optimization
Continuous improvements on the fuel injection system allows more flexible fuel
injection capability with higher injection pressure, which can provide more opportunities to
improve engine fuel economy, while maintaining the same emission level. Combustion
system optimization, featuring piston bowl, injector tip and the number of holes, in
conjunction with the advanced fuel injection system, is able to further improve engine
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
Effectiveness
performance and fuel economy. At this point, all engine manufacturers spearhead substantial
efforts into this direction in the hope that their development efforts would be translated into
production in the near futures. The examples include the combustion development programs
conducted by Cummins21 and Detroit Diesel22 funded by Department of Energy. They both
claim that 10 percent thermal efficiency improvement at 2010 emission level is achievable.
While their findings are still more towards research environment, their results do enhance the
possibility that some of technologies they are developing could be applied to production in the
time frame of 2017.
The cost for this technology includes costs associated with several individual
technologies. Specifically, improved cylinder head, turbo efficiency improvements, EGR
cooler improvements, higher pressure fuel rail, improved fuel injectors and improved pistons.
The costs estimates for each of these technologies are presented in Table 2-6 through Table
2-8 for heavy HD, medium HD and light HD engines, respectively. The agencies consider a
low complexity ICM of 1.11 and time based learning from 2014 forward to be appropriate for
these technologies.
2.4.2.3 Turbochargers
Many advanced turbocharger technologies can be potentially added into production in
the time frame between 2014 and 2017, and some of them are already in production.
Mechanical or electric turbocompound, two-stage turbochargers with intercooler, and high
efficient low speed compressor to just name a few.
A turbocompound system extracts energy from the exhaust to provide additional
power. Mechanical turbocompounding includes a power turbine located downstream of the
turbine which in turn is connected to the crankshaft to supply additional power. As noted in
the 2010 NAS report, it typically includes a fluid coupling (to allow for speed variation and to
protect the power turbine from engine torsional vibration) and a gear set to match power
turbine speed to crankshaft speed. Turbocompound has been used in production by Detroit
Diesel for their DD15 and DD16 engines and they claim a 3 to 5 percent fuel consumption
reduction due to the system. The 2010 NAS report23 includes published information from
four sources on the fuel consumption reduction from mechanical turbocompounding ranging
from 2.5 to 5 percent. Some of these differences may depend on the operating condition or
duty cycle that was considered by the different researchers. The performance of a
turbocompound system tends to be best at full load and much less or even act as an energy
sink to suck the energy at light loads. Because of that, a clutch that can separate the engine
crankshaft from turbocompound gear train could be proposed and put into production in order
to overcome the drawbacks of turbocompound at light loads, thus improving fuel economy
over the entire speed and load ranges. Incremental cost increases associated with the addition
of mechanical turbocompounding are significant, due to the complexity of the mechanical
power transmission system required to connect the power turbine to the drivetrain. Such costs
are estimated to be $1040 inclusive of an RPE factor of 1.28 (i.e., $813 in direct
manufacturing costs).
Electric turbocompound is another potential device, although it is still not as mature in
terms of production as opposed to mechanical turbocompound. An electric turbocompound
2-25
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Regulatory Impact Analysis
system uses a power turbine to drive an electrical generator which is used to power electric
accessories or provide extra power to the engine. As noted in the 2010 NAS report,24 electric
turbocompound is a technology that fits particularly well with a hybrid electric powertrain for
long-haul applications where regenerative braking opportunities are limited. The benefits of
electric turbocompound and an electric hybrid powertrain can be additive. . TIAX used a
range of 4 to 5 percent for its estimates, which included the benefits of electric accessories.25
The 2010 NAS report includes the benefit projections from three studies, as listed below.
However, none of these systems have been demonstrated commercially.26
• The NESCCAF/ICCT study modeled an electric turbocompound system and
estimated benefits at 4.2 percent, including electrification of accessories.
• Caterpillar, Inc., as part of Department of Energy (DOE) funded work,
modeled a system that showed 3 to 5 percent improvement27
• John Deere investigated a system (off-highway) that offered 10 percent
improvement.
Two-stage turbocharger technology has been used in production by Navistar and other
manufacturers. Ford's new developed 6.7L diesel engine features twin-compressor
turbocharger. Higher boost with wider range of operations and higher efficiency can further
enhance engine performance, thus fuel economy. It is expected that this type of technology
will continue to be improved by better matching with system and developing higher
compressor and turbine efficiency.
For this analysis, we have estimated the cost of turbocompounding at $823 (2008$).
This estimate includes a low complexity ICM of 1.11. This cost is applicable in the 2017MY
when engines being placed in day cab and sleeper cab tractors are expected to add this
technology. Time based learning is considered applicable to this technology. For the more
basic technology of improving the turbo efficiency, the agencies have estimated a cost of $17
(2008$) including a low complexity ICM of 1.11. That estimate would be considered valid in
the 2014MY and time based learning would be applied going forward.
2.4.2.4 Engine Parasitic and Friction Reduction
Engine parasitic and friction reduction is another key technical areas that can be
further improved in production moving to 2014 and 2017 time frame. Reduced friction in
bearings, valve trains, and the piston-to-liner interface will improve efficiency. Friction
reduction opportunities in the engine valve train and at its roller/tappet interfaces exist for
several production engines. The piston at its skirt/cylinder wall interface, wrist pin and oil
ring/cylinder wall interface offers opportunities for friction reduction. Use of more advanced
oil lubricant that could be available for production in the future can also play a key role in
reducing friction. Any friction reduction must be carefully developed to avoid issues with
durability or performance capability. Estimations of fuel consumption improvements due to
9R
reduced friction range from 0 percent to 2 percent. All fuel injection system manufacturers
are working hard to reduce parasitic loss due to high pressure pumps and common rail flow
loss in the hope that those development would add up further fuel economy improvement.
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
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Incremental manufacturing costs increases associated with the reduction of parasitics
and friction may include those associated with an optimized, electric water pump, replacing a
mechanically driven water pump ($100). Additionally, an improved mechanical oil pump
with more efficient relief mechanism and optimized hydrodynamic design may incur costs
($5). A fuel pump capable of delivering higher pressures and with efficient regulation may
require improved materials and more elaborate regulating hardware ($5). Improved Pistons
with less friction generated at the skirt may require incrementally more precision in finish
machine operations ($3). Finally, a more efficient, reduced friction valve train will require
more precise machining processes and an increased parts count ($90). All costs presented
here are considered to include a retail price equivalent factor of 1.28.
Removing the 1.28 RPE factor from the above cost estimates and instead applying a
low complexity ICM of 1.11 results in the following costs: electric water pump, $87;
improved mechanical oil pump, $4, improved fuel pump, $4; improved pistons, $3; reduced
friction valve train, $104 for LHDD engines and $78 for HHDD engines. All costs are in
2008 dollars and are applicable to the 2014MY. Time based learning is considered applicable
to all of these costs.
2.4.2.5 Advanced Model Based Control
Significant progresses on advanced model based control have been made in the past
few years. Detroit Diesel introduced the next generation model based control concept,
achieving 4 percent thermal efficiency improvement while simultaneously reducing emissions
in transient operations.29 Their model based concept features a series of real time optimizers
with multiple inputs and multiple outputs. This controller contains many physical based
models for engine and aftertreatment. It produces fully transient engine performance and
emissions predictions in a real-time manner. Although this control concept may still not be
mature in 2014 production, it would be a realistic estimate that this type of real time model
control could be in production before 2017, thus significantly improving engine fuel
economy.
2.4.2.6 Integrated Aftertreatment System
All manufacturers use diesel particulate filter (DPF) to reduce particulate matter (PM).
All except Navistar rely on SCR to reduce NOx emissions. Periodic regeneration to remove
loaded soot is required for all DPF. One way is to directly inject the fuel into exhaust stream,
called active regeneration, and a diesel oxidation catalyst (DOC) or other device then oxidizes
the fuel in the exhaust stream, providing the heat required for DPF regeneration and
increasing the fuel consumption of the vehicle. The other method is to use NO2, called
passive regeneration, to directly react with soot at much lower exhaust temperature than
active regeneration. Use of advanced thermal management could be made in production to
eliminate active regeneration, thus significantly improve fuel economy. Volvo has announced
in 2009 that their 2010 DPF+SCR system has eliminated active regeneration for on-highway
vehicles. All other manufacturers are working in the same direction, minimizing or
eliminating active regeneration, thus improving fuel economy at least by 1 percent, providing
efficiency improvements in the real world which are not reflected in the proposed HD engine
test procedure
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Regulatory Impact Analysis
Higher SCRNOX conversion efficiency will allow higher engine-out NOX emissions,
and therefore, will give more room for engine system optimization, while maintaining the
same or even less diesel engine fluid (DBF) consumption. Advanced model based control on
DEF usage and slip can further improve DEF consumption, thus fuel economy. For those
manufacturers that use SCR as their NOX reduction devices, properly integrated DPF and
SCR system is essential, which is not only able to improve emissions reductions, but also to
improve fuel economy through more advancing canning design, thus minimizing pressure
drop across the system. Improvements in aftertreatment system efficiency should be
technology cost neutral, requiring no increases in precious metal loading or manufacturing
expense, and only require additional development costs.
The agencies have estimated the cost of this technology at $25 for each percentage
improvement in fuel consumption. This estimate is based on the agencies' belief that this
technology is, in fact, a very cost effective approach to improving fuel consumption. As such,
$25 per percent improvement is considered a reasonable cost. This cost would cover the
engineering and test cell related costs necessary to develop and implement the improved
control strategies that would allow for the improvements in fuel consumption. Importantly,
the engineering work involved would be expected to result in cost savings to the
aftertreatment and control hardware (lower platinum group metal (PGM) loadings, lower
reductant dosing rates, etc.). Those savings are considered to be included in the $25 per
percent estimate described here. Given the 4 percent expected improvement in fuel
consumption results in an estimated cost of $111 (2008$) for a 2014MY vehicle. This
estimate includes a low complexity ICM of 1.11 and time based learning from 2014 forward.
Note that this cost is applied only to light-heavy HD diesel engines. The cost for this
technology is considered separately for medium and heavy HD diesel engines since the cost is
considered largely one of research and development which probably results in lower actual
part cost.
2.4.2.7 Electrification
Many accessories that are traditionally gear or belt driven by a vehicle's engine can be
decoupled with the engine speed, so that those accessories can be tailored to a specific engine
speed, thus better efficiency. Examples include the engine water pump, oil pump, fuel
injection pump, air compressor, power-steering pump, cooling fans, and the vehicle's air-
conditioning system. The most tangible development toward production in 2017 time frame
would be electric water and oil pumps. It is expected that about 0.5 to 1.0 percent thermal
efficiency improvement could be achieved with electrification of these two pumps.
Costs for electrification are considered as part of the costs for improved water and oil
pumps discussed in Section 2.4.2.4.
2.4.2.8 Waste Heat Recovery
Waste heat recovery uses exhaust gas or other heat sources (such as EGR or coolant)
from the primary engine to develop additional power. Waste heat recovery systems have other
names such as bottoming cycle or Rankine cycle. As described in the 2010 NAS report, a
typical system consists of the following components: a feed pump to drive the working fluid
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
Effectiveness
from the condenser to the evaporator (or boiler); the evaporator, which transfers waste heat
energy from the primary engine to the working fluid; an expander, which takes energy from
the working fluid to make mechanical power; and a condenser that rejects unused heat energy
from the bottoming cycle working fluid before starting a new cycle. The costs of
implementing a Waste Heat Recovery system are significant, estimated at $1700. Such costs
include necessary power extraction unit and gearbox, heat exchangers and compressor. The
2010 NAS report cited two studies related to waste heat recovery, as listed below.
30
• Cummins has shown a projected increase of thermal efficiency from 49.1 to
52.9 percent (7.2 percent decrease in fuel consumption) using an organic
Rankine cycle.31 Cummins reports recovering 2.5 thermal efficiency points
from the exhaust and 1.3 thermal efficiency points from the coolant and EGR
stream.
• The NESCCAF/ICCT report showed the effect of a steam bottoming cycle to
reduce fuel consumption by up to 10 percent.
The agencies' assessment of this technology indicates that it currently exists only in
the research phase, and therefore should not be included in proposing the standard for 2017
model year.
2.4.2.9 2014 Model Year HHD Diesel Engine Package
The agencies assessed the impact of technologies over each of the SET modes to
project an overall improvement in the 2014 model year. The agencies considered
improvements in parasitic and friction losses through piston designs to reduce friction,
improved lubrication, and improved water pump and oil pump designs to reduce parasitic
losses. The aftertreatment improvements are available through lower backpressure of the
systems and optimization of the engine-out NOx levels. Improvements to the EGR system
and air flow through the intake and exhaust systems, along with turbochargers can also
produce engine efficiency improvements. Lastly, an increase in combustion pressures and
controls can reduce fuel consumption of the engine. The projected impact of each set of these
technologies is included in Table 2-5. Based on the improvements listed in the table, the
overall weighted reduction based on the SET mode weightings is projected at 3 percent
Table 2-5: Projected Percent CO2 Impact for SET Modes in 2014 Model Year
SET
Mode
1
2
o
J
4
5
6
7
8
Speed,
percent
Load
Idle
A, 100
B, 50
B,75
A, 50
A, 75
A, 25
B, 100
Parasitic,
Friction
0.0
-0.9
-0.9
-1.1
-0.4
-0.7
-0.2
-1.3
Aftertreatment
Improvement
0.0
-1.1
-1.1
-1.3
-0.7
-0.9
-0.4
-1.3
Air Handling
0.0
-1.1
-1.1
-1.3
-1.1
-1.3
-0.9
-1.3
Combustion,
Control
-0.4
-0.9
-1.1
-1.3
-0.9
-1.1
-0.4
-0.9
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Regulatory Impact Analysis
9
10
11
12
13
B, 25
C, 100
C, 25
C, 75
C, 50
-0.7
-1.7
-0.9
-1.3
-1.1
-0.9
-1.5
-0.9
-1.3
-1.1
-0.9
-1.3
-0.9
-1.1
-0.9
-0.4
-0.9
-0.2
-0.4
-0.7
The agencies derived the HHD diesel engine FTP technology effectiveness for the
2014 model year based on a similar approach. Using the same technologies as discussed for
the HHD diesel engine SET above, the agencies project the reductions at 3 percent. It should
be pointed out that individual technology improvement is not additive to each other due to the
interaction of technology to technology.
2-6.
The cost estimates for the complete HHD diesel engine packages are shown in Table
Table 2-6 Technology and Package Costs for HHD Diesel Engines (2008$)
Technology
Cylinder Head
Turbo efficiency
EGR cooler
Water pump
Oil pump
Fuel pump
Fuel rail
Fuel injector
Piston
Turbo -compounding (engines placed in combination tractors only)
HHDD Total (vocational truck engines)
HHDD Total (combination tractors)
2014
$6
$17
$3
$87
$4
$4
$10
$10
$3
$0
$145
$145
2015
$6
$17
$3
$84
$4
$4
$9
$10
$3
$0
$140
$140
2016
$6
$16
$3
$82
$4
$4
$9
$10
$2
$0
$136
$136
2017
$6
$16
$3
$79
$4
$4
$9
$9
$2
$823
$132
$955
2.4.2.10 2014 Model Year LHD/MHD Diesel Engine Package
The agencies considered the same 2014 model year technology package developed for
the HHD diesel engines for the LHD diesel and MHD diesel engines. The package includes
parasitic and friction reduction, improved lubrication, aftertreatment improvements, EGR
system and air flow improvements, and combustion pressure increase and controls to reduce
fuel consumption of the engine. The agencies project that these improvements will produce a
5 percent reduction in fuel consumption and
The cost estimates for the complete MHD diesel engines are shown in Table 2-7. The
cost estimates for the complete LHD diesel engines are shown in Table 2-8.
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
Effectiveness
Table 2-7 Technology and Package Costs for MHD Diesel Engines (2008$)
Technology
Cylinder Head
Turbo efficiency
EGR cooler
Water pump
Oil pump
Fuel pump
Fuel rail
Fuel injector
Piston
Valve train friction reduction
Turbo-compounding (engines placed in combination tractors only)
MHDD Total (vocational truck engines)
MHDD Total (combination tractors)
2014
$6
$17
$3
$87
$4
$4
$10
$10
$o
3
$78
$0
$223
$223
2015
$6
$17
$3
$84
$4
$4
$9
$10
$3
$76
$0
$216
$216
2016
$6
$16
$3
$82
$4
$4
$9
$10
$2
$73
$0
$210
$210
2017
$6
$16
$3
$79
$4
$4
$9
$9
$2
$71
$823
$203
$1,027
Table 2-8 Technology and Package Costs for LHD Diesel Engines (2008$)
Technology
Aftertreatment improvements
Cylinder Head
Turbo efficiency
EGR cooler
Water pump
Oil pump
Fuel pump
Fuel rail
Fuel injector
Piston
Valve train friction reduction
LHDD Total
2014
$111
$10
$17
$3
$87
$4
$4
$11
$14
$o
3
$104
$369
2015
$108
$10
$17
$3
$84
$4
$4
$11
$13
$o
3
$101
$358
2016
$104
$10
$16
$3
$82
$4
$4
$11
$13
$2
$98
$348
2017
$101
$9
$16
$3
$79
$4
$4
$10
$13
$2
$95
$337
2.4.2.11 2014 Model Year Diesel Engine Standards
The agencies applied the 5 percent reduction for the LHDD/MHDD engines and the 3
percent reduction for the HHD diesel engines based on the projected technology package
improvements in 2014 model year to the 2010 model year baseline performance included in
Table 2-4. The results are the proposed 2014 model year standards, as shown in Table 2-9.
Table 2-9: 2014 Model Year Proposed Standards (g CO2/bhp-hr)
ILHDD - FTP
600
MHDD - FTP
600
HHDD - FTP
567
MHDD - SET
502
HHDD - SET
475
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Regulatory Impact Analysis
2.4.2.12 2017 Model Year HHDD Engine Package
The agencies assessed the impact of technologies over each of the SET modes to
project an overall improvement in the 2017 model year. The agencies considered additional
improvements in the technologies included in the 2014 model year package in addition to
turbocompounding. The projected impact of each set of these technologies is included in
Table 2-10. Based on the improvements listed in the table, the overall weighted reduction
based on the SET mode weightings is projected at 6 percent.
Costs for 2017 are shown in Table 2-6.
Table 2-10: Projected CO2 Improvements for SET Modes in 2017 Model Year
SET
Mode
1
2
o
J
4
5
6
7
8
9
10
11
12
13
Speed,
Percent
Load
Idle
A, 100
B, 50
B, 75
A, 50
A, 75
A, 25
B, 100
B, 25
C, 100
C, 25
C,75
C, 50
Turbo-
compounding
0.2
-4.50
-2.50
-4.50
-1.50
-4.00
0.20
-5.50
0.30
-5.00
0.50
-3.50
-2.00
Parasitic,
Friction
0.00
-1.00
-1.00
-1.25
-0.50
-0.75
-0.25
-1.50
-0.75
-2.00
-1.00
-1.50
-1.25
Aftertreatment
Improvement
0.00
-1.25
-1.25
-1.50
-0.75
-1.00
-0.50
-1.50
-1.00
-1.75
-1.00
-1.50
-1.25
Air
handling
0.00
- .25
- .25
- .50
- .25
- .50
- .00
- .50
- .00
- .50
- .00
- .25
- .00
Combustion,
Control
-0.50
-1.00
-1.25
-1.50
-1.00
-1.25
-0.50
-1.00
-0.50
-1.00
-0.25
-0.50
-0.75
The agencies derived the HHDD FTP technology package effectiveness for the 2017
model year based on a similar approach. However, the addition of turbocompounding shows
a greater effectiveness on the SET cycle than the FTP cycle because of the steady state nature
and amount of time spent at higher speeds and loads during the SET. Using the same
technologies as discussed for the HHDD SET above, the agencies project the reductions at 5
percent for the FTP. It is noticed that there is a small penalty on CO2 using
turbocompounding at low loads from Table 2-5, since no mechanism to disengage
turbocompounding and engine crankshaft is proposed in this table. This means that an
introduction of a clutch to disengage turbocompound and engine whenever the
turbocompounding does not provide positive work will further improve CC>2 reduction.
Similar to Table 2-3, individual technology in Table 2-5 is not additive to each other due to
the interaction of technology to technology.
2.4.2.13 2017 Model Year LHD/MHD Diesel Engine Package
The agencies developed the 2017 model year LHD/MHD diesel engine package based
on additional improvements in the technologies included in the 2014 model year package.
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
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The projected impact of these technologies provides an overall reduction of 9 percent over the
2010 model year baseline.
Costs for the 2017 model year are shown in Table 2-7 (MHD) and Table 2-8 (LHD).
2.4.2.14 2017 Model Year Diesel Engine Standards
The agencies applied the 8.6 percent reduction for the LHD/MHD diesel engines and
the 5 percent reduction for the HHD diesel engines using the FTP and a 6.1 percent reduction
for HHD diesel engines using the SET based on the projected technology package
improvements in 2017 model year to the 2010 model year baseline performance included in
Table 2-4. The results are the proposed 2014 model year standards, as shown in Table 2-11.
Table 2-11 2017 Model Year Proposed Standards (g CO2/bhp-hr)
ILHDD - FTP
576
MHDD - FTP
576
HHDD - FTP
555
MHDD - SET
487
HHDD - SET
460
2.5 Class 7/8 Day Cabs and Sleeper Cabs
The proposed regulatory category for Class 7 and 8 day and sleeper cabs involves
seven regulatory subcategories.
Class 7 Day Cab with Low/Mid Roof
Class 7 Day Cab with High Roof
Class 8 Day Cab with Low/Mid Roof
Class 8 Day Cab with High Roof
Class 8 Sleeper Cab with Low Roof
Class 8 Sleeper Cab with Mid Roof
Class 8 Sleeper Cab with High Roof
The regulatory subcategories are being proposed to differentiate between tractor
usages through using characteristics of the truck. The technologies being proposed to reduce
fuel consumption and CC>2 emissions from tractors can be developed for all seven
subcategories. However, the typical usage pattern may limit the penetration rate of the
technology. For example, aerodynamic improvements can reduce the fuel consumption and
CC>2 emissions of a tractor at high speeds. However, this technology could be a detriment to
fuel consumption if applied to a tractor travelling at low speeds. The agencies discuss
technologies, penetration rates, and costs for each regulatory subcategory in the sections
below.
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Regulatory Impact Analysis
2.5.1 Aerodynamics
Up to 25 percent of the fuel consumed by a line-haul truck traveling at highway speeds
is used to overcome aerodynamic drag forces, making aerodynamic drag a significant
contributor to a Class 7 or 8 tractor's GHG emissions and fuel consumption.32 Because
aerodynamic drag varies by the square of the vehicle speed, small changes in the tractor
aerodynamics can have significant impacts on GHG emissions and fuel efficiency of that
vehicle. With much of their driving at highway speed, the benefits of reduced aerodynamic
drag for Class 7 or 8 tractors are significant.33
The common measure of aerodynamic efficiency is the coefficient of drag (Cd). The
aerodynamic drag force (i.e., the force the vehicle must overcome due to air) is a function the
Cd, the area presented to the wind (i.e., the projected area perpendicular to the direction of
travel or frontal area), and the cube of the vehicle speed. Cds for today's fleet typically range
from greater than 0.80 for a "classic" body tractor to approximately 0.58 for tractors that
incorporate a full package of widely, commercially available aerodynamic features.
2.5.1.1 Challenges of Tractor Aerodynamics
The aerodynamic efficiency of heavy-duty vehicles has gained increasing interest in
recent years as fuel prices, competitive freight markets, and overall environmental awareness
has focused owners and operators on getting as much useful work out of every gallon of
diesel fuel as possible. While designers of heavy-duty vehicles and aftermarket products try
to aerodynamically streamline heavy-duty vehicles, there are some challenges. Foremost is
balancing the need to maximize the amount of freight that can be transported. For a tractor,
this often means pulling a trailer that is as tall and as wide as motor safety laws permit,
thereby presenting a large, drag-inducing area perpendicular to the wind (i.e., projected
frontal area). As a result, the tractor must also present a relatively large projected frontal area
to smoothly manage the flow of air along the cab and transition it to trailer. In instances
where the height of the cab is not properly matched with that of trailer, aerodynamic drag can
be significantly increased by creating large wakes (when the trailer is much shorter than the
cab) or presenting a large non-aerodynamic surface (when the trailer is taller than the cab).
Aerodynamic design must also meet practical and safety needs such as providing for physical
access and visual inspections of vehicle equipment. Because weight added to the vehicle
impacts its overall fuel efficiency and GHG emissions and, in some circumstances the amount
of freight the vehicle can carry, aerodynamic design and devices will sacrifice some benefit to
overcoming their contribution to the vehicle weight. Aerodynamic designs and devices also
must balance being as light and streamlined as possible with being durable enough to
withstand the rigors a working, freight vehicle encounters while traveling or loading and
unloading. Durability can be a significant concern for cabs designed for specialty
applications, such as "severe duty" cabs that may operate on unimproved roads. In addition,
absent mandatory requirements, aerodynamic features for heavy-duty vehicles must appeal to
the owners and operators. Finally, because the behavior of airflow across the cab (and cab
and trailer combination) is dependent upon the entire system, it isn't possible to make
inferences about the vehicles aerodynamic performance based upon the performance of
individual components. This can make it difficult to assess the benefit of adding (or
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subtracting) individual aerodynamic features and can discourage owners and operators from
adopting aerodynamic technologies.
2.5.1.2 Technology to Reduce Aerodynamic Drag
Addressing aerodynamic drag in Class 7 and tractors requires considering the entire
vehicle as a system to include the tractor and trailer. The overall shape can be optimized to
minimize aerodynamic drag and, in fact, the tractor body must have at least a moderately
aerodynamic shape (and its relatively smooth flow) to benefit from add-on aerodynamic
components. Whether integrated into the shape of the tractor body or as an add-on
component to a generally aerodynamic tractor, there is a wide range of technologies available
for Class 7 and 8 tractors. Table 2-12 describes several of these potential aerodynamic
features and components.
Table 2-12: Technologies to Address Aerodynamic Drag
LOCATION
ON CAB
Front
Side
Top
Rear
Undercarriage
Accessories
General
General
TECHNOLOGY
TYPE
Bumper, grill, hood,
windshield
Fuel tank fairings
Roof fairings
(integrated) and wind
visors (attached)
Side extending gap
reducers
Underbelly treatment
Mirrors, signal horns,
exhaust
Active air management
Advanced, passive air
management
DESIGNED EFFECT
Minimize pressure created by front of vehicle moving
ambient air to make way for truck
Reduce surface area perpendicular to wind, minimize
opportunity to trap airflow, and smooth surface
Transition air to flow smoothly over trailer and
minimize surface area perpendicular to the wind (for
tractor and trailer)
Transition air to flow smoothly over trailer and reduce
entrapment of air in gap between tractor and trailer
Manage flow of air underneath tractor to reduce
eddies and smoothly transition flow to trailer
Reducing surface area perpendicular to travel and
minimizing complex shapes that may induce drag
Manage airflow by actively directing or blowing air
into reduce pressure drag
Manage airflow through passive aerodynamic shapes
or devices that keep flow attached to the vehicle
(tractor and trailer)
2.5.1.3 Aerodynamics in the Current Fleet
Aerodynamics in the Class 7 and 8 tractors fleet currently on the road ranges from
trucks with few modern aerodynamic features to those that address the major areas of
aerodynamic drag to tractors applying more advanced techniques. Because they operate at
highway speeds less of the time, Class 7 and 8 tractors configured as day cabs (i.e., dedicated
to regional routes) tend to have fewer aerodynamic features than cabs designed for line-haul
applications. For tractors, it's useful to consider aerodynamics in the current fleet as in three
packages: the "classic" truck body; the "conventional" truck body; and the "SmartWay" truck
body.
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"Classic" truck body: At the lower end of aerodynamic performance are tractors that
have a "classic" truck body. These truck bodies prioritize looks or special duty capabilities
(e.g., clearance, durability on unimproved roads, and visual access to key vehicle
components) and have remained relatively unchanged since the 1970's. Typical applications
are logging, waste hauling, and some agricultural related uses. These trucks incorporate few,
if any, aerodynamic features and several that detract from aerodynamics including equipment
such as bug deflectors, custom sunshades, air cleaners, b-pillar exhaust stacks, additional
horns, lights and mirrors may constitute a conventional vehicle.
"Conventional" truck body: The conventional, modern truck capitalizes on a
generally aerodynamic shape and avoids classic features that increase drag. The conventional,
modern truck body has removed extra equipment (e.g., bug deflectors, custom sunshades,
additional signal horns, decorative lights), moved essential equipment out of the airflow (e.g.,
b-pillar exhaust stacks and air cleaners), and streamlined fixed-position, essential equipment
(e.g., mirrors, steps, and safety lights).
"SmartWay" truck body: The SmartWay aerodynamic package builds off of the
aerodynamic package required for a Class 8 sleeper cab high roof tractor to meet the
SmartWay design specifications and represents the top aerodynamic package widely,
commercially available. The SmartWay package is a fully aerodynamic truck package which
has an overall streamlined shape, removes drag inducing features (i.e., those removed or
moved in conventional, modern truck body), and adds components to reduce drag in the most
significant areas on the tractor. This includes aerodynamic features at the front to the tractor
(e.g., streamlined bumper, grill, and hood), sides (i.e., fuel tank fairings and streamlined
mirrors), top (i.e., roof fairings), and rear (i.e., side extending gap reducers). Regional and
line-haul applications often employ different approaches, such as removable, rooftop wind
visors and fully integrated, enclosed roof fairings, respectively, based upon their intended
operation.
More advanced aerodynamic features are possible and are the focus of product
development, pilot and testing projects, and, in some cases, product lines that have seen
limited fleet adoption. Advanced aerodynamic designs can further optimize the overall shape
of the tractor and may add other advanced aerodynamic features (e.g., underbody airflow
treatment, down exhaust, and lowered ride height). Some advanced aerodynamic features,
including those listed above, show promise but will likely need ongoing refinement as these
technologies are tailored to specific applications and payback periods are reduced. Fleets
with whose line-haul operations permit are currently testing and using some advanced
aerodynamic technologies.
2.5.1.4 Aerodynamic Bins
The agencies have characterized the typical aerodynamic performance (expressed as
Cd) and cost for select applications. To do so, it was necessary to represent the wide variety
of tractor aerodynamic shapes - which are a collection of the shapes of the multitude of
component parts - by developing aerodynamic packages. These are the "classic,"
"conventional," "SmartWay," "Advanced SmartWay," and the "Advanced SmartWay II."
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"Classic" aerodynamic package: As described in section 2.4.1.3, these trucks
incorporate few, if any, aerodynamic features and several that detract from aerodynamics
including equipment such as bug deflectors, custom sunshades, air cleaners, b-pillar exhaust
stacks, additional horns, lights and mirrors may constitute a conventional vehicle. No cost for
aerodynamics is assumed for the classic package.
"Conventional" package: As described in section 2.4.13, the conventional, modern
truck capitalizes on a generally aerodynamic shape and avoids classic features that increase
drag. No cost for aerodynamics is assumed for the conventional package since there has been
no addition of additional body work and these moderate modifications to the tractor shape
would not likely require the redesign of other components.
"SmartWay" package: Based upon the design requirements of EPA's SmartWay
Certified Tractors, this package has an overall streamlined shape, removes drag inducing
features, and adds components (i.e., aerodynamic mirrors, side fairings, aerodynamic
bumpers, and side extending gap reducers) to reduce drag in the most significant areas on the
tractor. The SmartWay aerodynamics package does add some incremental cost above the
classic and conventional packages.
"Advanced SmartWay" and "Advanced SmartWay II" packages: These packages
include components similar to that found in the SmartWay package but with additional
aerodynamic refinement. This can be a combination of more sophisticated shape and
increased coverage of drag inducing elements. Where the Advanced SmartWay package
represents a tractor using the most advanced aerodynamics available today, the Advanced
SmartWay II package is designed to represent aerodynamics expected to be available in the
near future. With more attention paid to aerodynamic performance than the conventional
package, the Advanced SmartWay package is estimated to be slightly more expensive. As a
representation of the future aerodynamics, the Advanced SmartWay II package is estimated as
being 50 percent more expensive than the Advanced SmartWay package.
The agencies developed the typical coefficient of drag (Cd) values for the truck
categories based on coastdown testing conducted by EPA and from literature surveys. If the
Cd values found in literature were described with a frontal area, then they were converted to a
Cd value that represents the frontal area being proposed by the agencies for each subcategory.
In addition to the absolute values, the agencies used the results of a wind tunnel evaluation of
aerodynamic components. SAE 2006-01-3456 evaluated aerodynamic components on a Class
8 high roof tractor and found that side extenders provide a Cd reduction of 0.04 and tank and
cab skirts provide a Cd reduction of 0.03.34
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Regulatory Impact Analysis
Table 2-13: Tractor Cd Values
Truck
Expected Bin
Source
Frontal
Area (m2)
Cd
Class 8 Sleeper Cab High Roof
International ProStar
MAS - Improved Tractor
SmartWay Tractor
Best Aero Truck
Full Aero
Roof Deflector
International 92001 #1
International 9200I #2
CE-CERT
No Aero Feature
Baseline Truck
SmartWay -
Adv.
SmartWay
Adv.
SmartWay
SmartWay
SmartWay
SmartWay
Conventional
Conventional
Conventional
Conventional
Classic
Classic
ATDSJD
2010 MAS Report
2010 MAS Report
DDC Spec Manager
EPA PERE &
MOVES Model
EPA PERE &
MOVES Model
TRC
NVFEL
EPA PERE &
MOVES Model
DDC Spec Manager
McCallen, 1999
9.8
unknown
unknown
9.8
9.8
9.8
9.8
9.8
9.8
9.8
9.8
0.54-0.56
0.55-0.56
0.59-0.60
0.61
0.59
0.65
0.71
0.70
0.74
0.77
0.77
Class 8 Day Cab High Roof
International ProStar
Aero Features
Roof Fairing Only
SmartWay
SmartWay
Conventional
ATDS
SAE 2005-01 -351 2
SAE 2005-01 -351 2
9.8
9.8
9.8
0.58
0.61
0.66
Class 8 Day Cab Low Roof
International ProStar
Conventional
- SmartWay
ATDS
6.0
0.78
Based on the testing and literature information, the agencies developed the Cd value
for each aerodynamic bin and tractor subcategory, as shown in Table 2-14.
Table 2-14: Coefficient of Drag Performance of the Aerodynamic Bins
Class 7
Day Cab
Low
Roof
High
Roof
Class 8
Day Cab
Low Roof
High
Roof
Sleeper Cab
Low
Roof
Mid
Roof
High
Roof
Aerodynamics (Cd)
Frontal Area (m^)
Classic
Conventional
SmartWay
Advanced SmartWay
Advanced SmartWay
II
6.0
0.85
0.80
0.75
0.70
0.65
9.8
0.75
0.68
0.60
0.55
0.50
6.0
0.85
0.80
0.75
0.70
0.65
9.8
0.75
0.68
0.60
0.55
0.50
6.0
0.85
0.80
0.75
0.70
0.65
7.7
0.80
0.75
0.70
0.65
0.60
9.8
0.75
0.68
0.60
0.55
0.50
The agencies estimated the cost of the aerodynamic packages based on ICF's price
estimates.36 The agencies applied a 15 percent reduction to the prices to reflect a large
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volume discount which would be applicable to the tractor manufacturers. Although
technologies such as roof fairings may already be in widespread use today, the ICF study
researched retail prices that a consumer would pay for the purchase of a single item in
addition to researching possible discounts based on a large volume sale, therefore this 15
percent discount was applied to reflect bulk purchases on these items. In addition, the
agencies removed an RPE of 1.36 to obtain the direct manufacturer cost and then applied a
low complexity ICM of 1.14 or a medium complexity ICM of 1.26 (for Advanced SmartWay
II) to obtain the overall technology costs included in Table 2-15 and Table 2-16. In Table
2-17 and Table 2-18 the costs are shown including the expected penetration rates which range
between 20 percent and 50 percent for most technologies shown.
Table 2-15 Estimated Aerodynamic Technology Costs for Class 7 & 8 Day Cabs for the 2014MY (2008$)
Classic
Conventional
SmartWay
Advanced SmartWay
Advanced SmartWay II
CLASS 7 DAYCAB
Low Roof
$0
$0
$1,079
$2,179
$3,070
High Roof
$0
$0
$1,107
$2,207
$3,111
CLASS 8 DAYCAB
Low Roof
$0
$0
$1,079
$2,179
$3,070
High Roof
$0
$0
$1,107
$2,207
$3,111
Table 2-16 Estimated Aerodynamic Technology Costs for Class 8 Sleeper Cabs for the 2014My (2008$)
Classic
Conventional
SmartWay
Advanced SmartWay
Advanced SmartWay II
LOW ROOF
$0
$0
$1,317
$2,492
$3,512
MID ROOF
$0
$0
$1,345
$2,492
$3,512
HIGH ROOF
$0
$0
$1,495
$2,564
$3,613
Table 2-17 Estimated Aerodynamic Technology Costs for Class 7 & 8 Day Cabs for the 2014MY Inclusive
of Penetration Rates (2008$)
SmartWay
Advanced SmartWay
CLASS 7 DAYCAB
Low Roof
$539
$436
High Roof
$775
$441
CLASS 8 DAYCAB
Low Roof
$647
$0
High Roof
$332
$883
Table 2-18 Estimated Aerodynamic Technology Costs for Class 8 Sleeper Cabs for the 2014MY Inclusive
of Penetration Rates (2008$)
SmartWay
Advanced SmartWay
LOW ROOF
$527
$498
MID ROOF
$404
$748
HIGH ROOF
$1,271
$256
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Regulatory Impact Analysis
2.5.2 Tires
Tire rolling resistance is defined as the energy consumed by the tire per unit of
distance traveled. Energy is consumed mainly by the deformation of the tires, known as
hysteresis, but smaller losses are due to aerodynamic drag and other friction forces between
the tire and road surface and tire and wheel rim. About 90 percent of a tire's rolling resistance
comes from hysteresis. Collectively the forces that result in energy loss from the tires are
referred to as rolling resistance. The share of truck energy required to overcome rolling
resistance is estimated at nearly 13 percent for Class 8 trucks3 . Reducing a tire's rolling
resistance will reduce fuel consumption and lower emissions of CC>2 and other greenhouse
gases. Low rolling resistance tires are commercially available from most tire manufacturers.
The EPA SmartWay program identified test methods and established criteria to designate
certain tires as "low rolling resistance" for use in the program's emissions tracking system,
verification program, and SmartWay vehicle specifications. Below is a discussion of EPA's
approach to quantifying tire rolling resistance and the emission reductions associated with
reduced rolling resistance, and a discussion of single wide tires, retread tires, and replacement
tires.
To measure a tire's efficiency the vertical load supported by the tire must be factored
because rolling resistance is a function of the load on a tire. EPA uses a tire's rolling
resistance coefficient (RRC), which is measured as the rolling resistance force over vertical
load (kg/metric ton). The RRC baseline for today's fleet is 7.8 kg/metric ton for the steer tire
and 8.2 kg/metric ton for the drive tire, based on sales weighting of the top three
manufacturers based on market share. These values are based on new tires, since rolling
resistance decreases as the tread wears.
Beginning in 2007, EPA began designating certain Class 8 sleeper-cab configurations
as Certified SmartWay Tractors. In order for a tractor to be designated as Certified
SmartWay, the tractor must be equipped with verified low rolling resistance tires (either dual
or single wide), among other criteria. In order to be verified as a low rolling resistance tire, a
steer tire must have a RRC less than 6.6 kg/metric ton and a drive tire must have a RRC less
than 7.0 kg/metric ton. SmartWay-verified low rolling resistance tires are the best performing
tires available based on fuel efficiency. The SmartWay program expects to decrease the
maximum allowable rolling resistance coefficient by 10 percent between 2010 and 2014. As
more low rolling resistance tires are sold, the baseline rolling resistance coefficient value will
improve.
Research indicates the contribution to overall vehicle fuel efficiency by tires is
approximately equal to the proportion of the vehicle weight on them38. On a fully loaded
typical Class 8 long-haul truck (tractor and trailer), about 12.5 percent of the total tire energy
loss attributed to rolling resistance is from the steer tires and about 42.5 percent is from the
drive tires. When evaluating just the tractor, the proportionate amount of energy loss would
be about 24 percent from the steer tires and 76 percent from the drive tires.
A tire's rolling resistance is a factor considered in the design of the tire. It is a result
of the tread compound material, the architect of the casing, tread design and the tire
manufacturing process. Differences in rolling resistance of up to 50 percent have been
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identified for tires designed to equip the same vehicle39. It is estimated that 35 percent to 50
percent of a tire's rolling resistance is from the tread and the other 50 to 65 percent is from the
casing. Tires with increased RRC values are likely designed for treadwear and not fuel
efficiency.
Research and testing have shown a 5 percent reduction of rolling resistance provides a
fuel consumption reduction of 1 percent while maintaining similar traction and handling
characteristics. Bridgestone found a 5 percent improvement in rolling resistance will produce
a 1.3 to 1.7 percent improvement in fuel economy. Assuming a truck achieves 6 miles per
gallon and is driven 100,000 miles annually, a 1.5 percent improvement in fuel economy
results in a fuel consumption reduction of 1.48 percent, which is in line with EPA's study.
According to Bridgestone, use of a fuel-efficient tire will result in approximately a 12 percent
improvement in fuel economy compared to a non-fuel efficient tire at 55 mph, and 9 percent
improvement in fuel economy at 65 mph.
To further demonstrate the correlation between rolling resistance and fuel economy,
Michelin modeled vehicle fuel consumption using two drive cycles and various rolling
resistance values. One drive cycle incorporated several instances of stop and start that
replicated driving a vehicle on a secondary road; the other drive cycle replicated driving on a
highway at nearly uniform speed but with several elevation changes. Simulations were
performed using a base case and for rolling resistance reductions of 10 percent and 20 percent
for both the secondary roadway and highway drive cycles. The simulation modeling for the
secondary road drive cycle predicts a 1.8 percent and a 3.6 percent improvement in fuel
economy as a result of the 10 percent and 20 percent reduction in rolling resistance,
respectively40. The simulation modeling for the highway drive cycle predicts a 2.6 percent
and a 4.9 percent improvement in fuel economy as a result of the 10 percent and 20 percent
reduction in rolling resistance, respectively. The modeling demonstrates less of a benefit
from reduced rolling resistance when a vehicle is operated on secondary roadways. The
modeling predicts an improvement in fuel economy from a reduction in rolling resistance
comparable to what Bridgestone demonstrated. A 5 percent reduction in rolling resistance
results in a 1 percent improvement in fuel economy.
Proper tire inflation is critical to maintaining proper stress distribution in the tire,
which reduces heat loss and rolling resistance. Tires with reduced inflation pressure exhibit
more sidewall bending and tread shearing, therefore, have greater rolling resistance than a tire
operating at its optimal inflation pressure. Bridgestone tested the effect of inflation pressure
and found a 2 percent variation in fuel consumption over a 40 psi range. Generally, a 10 psi
reduction in overall tire inflation results in about a 1 percent reduction in fuel economy41. To
achieve the intended fuel economy benefits of low rolling resistance tires, it is critical that
tires are properly maintained.
Tire rolling resistance is only one of several performance criteria that affect tire
selection. The characteristics of a tire also influence durability, traction control, vehicle
handling and comfort. A single performance parameter can easily be enhanced, but an
optimal balance of all the criteria must be maintained. Tire design requires balancing
performance, since changes in design may change different performance characteristics in
opposing direction42. Truck tires are most often axle-specific in relation to these different
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Regulatory Impact Analysis
performance criteria43. The same tire on different axles or used in different applications can a
have different rolling resistance value. Any changes to a tire would generally be accompanied
with additional changes to suspension tuning and/or suspension design.
The Center for Transportation Research at Argonne National Laboratory analyzed
technology options to support energy use projections. The Center estimated the incremental
cost of low rolling resistance tires of $15 - $20 per tire. The ICF report estimated the cost of
low rolling resistance steer and drive tires to be $20 and $43 per tire, respectively. The NAS
panel estimated $30 per tire. EPA and NHTSA project a cost of $65 (2008$) for low rolling
resistance steer tires (2 per truck) for both Class 7 and 8 tractors including a low complexity
ICM of 1.14. For low rolling resistance drive tires, the agencies estimate truck-based costs of
$60 (2008$) and $121(2008$) for Class 7 and 8 tractors, respectively, including a low
complexity ICM of 1.14. The higher Class 8 reflects the assumption of one drive axle for
Class 7 tractors and two drive axles for Class 8 tractors. All costs are considered valid for the
2014MY and time based learning would be considered appropriate for this technology.
2.5.2.1 Single Wide Tires
Low rolling resistance tires are offered for dual assembly and as single wide tires.
They are typically only used on the drive axle of a tractor. A single wide tire is a larger tire
with a lower profile. The common single wide sizes include: 385/65R22.5, 425/65R22.5,
445/65R22.5, 435/50R22.5 and 445/50R22.5. Generally, a single wide tire has less sidewall
flexing compared to a dual assembly and therefore less hysteresis occurs. Compared to a dual
tire assembly, single wide tires also produce less aerodynamic resistance or drag. Single wide
tires can contribute to improving a vehicle's fuel efficiency through design as a low rolling
resistance tire and/or through vehicle weight reduction.
The use of fuel efficient single wide tires can reduce rolling resistance by 3.7 to 4.9
percent compared to the most equivalent dual tire44. An EPA study demonstrated an
improvement in fuel economy of 6 percent at 55 mph on the highway, 13 percent at 65 mph
on the highway and 10 percent on a suburban loop45 using single wide tires on the drive and
trailer axles. EPA attributed the fuel economy improvement to the reduction in rolling
resistance and vehicle weight reduction from using single wide tires. In 2008 the Department
of Energy (DOE) compared the effect of different combinations of tires on the fuel efficiency
of Class-8 trucks. The data collected based on field testing indicates that trucks with tractors
equipped with single wide tires on the drive axle experience better fuel economy than trucks
with tractors equipped with dual tires, independent of the type of tire on the trailer46. This
study in particular indicated a 6.2 percent improvement in fuel economy from single wide
tires.
There is also a weight savings associated with single wide tires compared to dual tires.
Single wide tires can reduce a tractor and trailer's weight by as much as 1,000 Ibs. when
combined with aluminum wheels. Bulk haulers of gasoline and other liquids recognize the
immediate advantage in carrying capacity provided by the reduction in the weight of tires and
have led the transportation industry in retrofitting their tractors and trailers47.
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New generation single wide tires, which were first introduced in 2000, are designed to
replace a set of dual tires on the drive and/or trailer positions. They are designed to be
,10
interchangeable with the dual tires without any change to the vehicle . If the vehicle does
not have hub-piloted wheels, there may be a need to retrofit axle components. In addition to
consideration of hub / bearing / axle, other axle-end components may be affected by use of
single wide tires. To assure successful operation, suitable components should be fitted as
recommended by the vehicle manufacturer49.
Current, single wide tires are wider than earlier models and legal in all 50 states for a
5-axle, 80,000 GVW truck. Single wide tires meet the "inch-width" requirements nationwide,
but are restricted in certain states up to 17,500 Ibs. on a single axle at 500 Ibs/inch width limit,
and are not allowed on single axle positions on certain double and triple combination vehicles.
An inch-width law regulates the maximum load that a tire can carry as a function of the tire
width. Typically single wide tires are optimized for highway operation and not city or on/off
highway operation. However, newer single wide tires are being designed for better scrub
resistance, which will allow an expansion of their use. The current market share of single
wide tires in combination tractor applications is 5 percent and the potential market is all
combination tractors.. New generation single wide tires represent an estimated 0.5 percent of
the 17.5 million tires sold each year in the U.S..
The Center for Transportation Research at Argonne National Laboratory estimated
incremental capital cost of single wide tires is $30 - $40 per tire. ICF estimates the
incremental price of low rolling resistance tires at $20 for drive tires and $43 for steer tires.50
With 4 single wide tires replacing 8 dual tires on the drive axle of a tractor, the incremental
cost would be between $120 and $160.
2.5.2.2 Replacement Tires
Original equipment (OE) tires are designed and marketed for specific applications and
vehicles. Their characteristics are optimized for the specific application and vehicle. Because
they are not sold as OE, replacement tires are generally designed for a variety of applications
and vehicle types that require different handling characteristics. The tires marketed to the
replacement tire market tend to place greater emphasis on tread wear, and therefore often have
higher rolling resistance than OE tires.
The market for replacement tires is individual vehicle owners and fleet owners and not
the vehicle manufacturers. Many fleets report that the cost of fuel as opposed to driver pay is
its number one cost. This has resulted in a greater demand for low rolling resistance
replacement tires. Both heavy-duty and medium-duty truck fleets are looking for ways to
reduce operational costs.
In 2007, EPA's SmartWay Transport Partnership introduced a means to distinguish
tires based on their rolling resistance. Since 2007 the number of low rolling resistance tires
available to vehicle owners and vehicle fleets has increased greatly, which is an indicator of
an increase in demand. EPA expects this trend to continue. In addition, effective January 1,
2010, California Air Resource Board requires that all tractor-trailers hauling dry van trailers
on any California road be equipped with SmartWay verified low rolling resistance tires; other
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Regulatory Impact Analysis
states may adopt this requirement. EPA expects this requirement will drive the demand for
low rolling resistance tires even further.
2.5.2.3 Retreaded Tires
The tread life of a tire is a measure of durability and some tires are designed
specifically for greater durability. Commercial truck tires are designed to be retreaded, a
process in which a new tread compound is adhered to the tire casing. The original tread of a
tire will last anywhere from 100,000 miles to over 300,000 miles, depending on vehicle
operation, original tread depth, tire axle position, and proper tire maintenance. Retreading can
extend the tire's useful life by 100,000 miles or more.51 In 2005, the Tire Industry
Association estimated that approximately 17.6 million retreaded truck tires were sold in North
America52.
To maintain the quality of the casing and increase the likelihood of retreading, a tire
should be retreaded before the tread depth is reduced to its legal limit. At any time, a steer
tire must have a tread depth of at least 4/32 of an inch and a drive tire must have a tread depth
of at least 2/32 of an inch (49 CFR. § 393.75). To protect the casing, a steer tire is generally
retreaded once the tread is worn down to 6/32 of an inch and a drive tire is retreaded once the
tread is worn down to 8/32 of an inch.53 Tires used on Class 8 vehicles are retreaded as many
as three times.
Both the casing and the tread contribute to a tire's rolling resistance. It is estimated
that 35 percent to 50 percent of a tire's rolling resistance is the result of the tread. Differences
in drive tire rolling resistance of up to 50 percent for the same casing with various tread
compounds have been demonstrated. For example, a fuel efficient tread compound (as
defined by the manufacturer) was added to two different casings resulting in an average
increase in rolling resistance of 48 percent. When a nonfuel efficient tread compound (also
defined by the manufacturer) was added to the same casings, the rolling resistance increased
by 125 percent on average. This characterizes the effect of the tread on the rolling resistance
of a tire.
Because tires can be retreaded multiple times, changes in the casing due to wear,
damage and material aging may impact rolling resistance to a greater degree than would occur
in an original tire. Additionally, as evidenced above, if a tread compound different than the
original tread is used, a retreaded tire can have higher or lower rolling resistance than the
original tire.
There is a cost savings associated with retread tires. A new retread costs between
$150 and $200, compared to a new tire which costs typically around $400. Since retreads are
not typically used on the steer axle position, this represents a savings of $1,600 to $2,000 per
tractor.
2.5.2.4 Tire Rolling Resistance
The agencies are projecting the following tire rolling resistance performance for
setting the proposed tractor standards, as shown in Table 2-19.
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Table 2-19 Tire Rolling Resistance
Class 7
Day Cab
Low/
Mid
Roof
High
Roof
Class 8
Day Cab
Low/Mid
Roof
High
Roof
Sleeper Cab
Low
Roof
Mid
Roof
High
Roof
Steer Tires (Crr kg/metric ton)
Baseline
SmartWay
Advanced SmartWay
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
Drive Tires (Crr kg/metric ton)
Baseline
SmartWay
Advanced SmartWay
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
2.5.3 Weight Reduction
Mass reduction encompasses a variety of techniques ranging from improved design
and better component integration to application of lighter and higher-strength materials. Mass
reduction can be further compounded by reductions in engine power and ancillary systems
(transmission, steering, brakes, suspension, etc.). Although common on light-duty passenger
vehicles for fuel economy and performance increases, mass reduction on heavy-duty vehicles
is more complex due to the size and duty cycle of the vehicles.
Reducing a vehicle's mass decreases fuel consumption and GHG output by reducing
the energy demand needed to overcome forces resisting motion, and rolling resistance.
Passenger vehicle manufacturers employ a systematic approach to mass reduction, where the
net mass reduction is the addition of a direct component or system mass reduction plus the
additional mass reduction taken from indirect ancillary systems and components, effectively
compounding or obtaining a secondary mass reduction from a primary mass reduction. For
example, use of a smaller, lighter engine with lower torque-output subsequently allows the
use of a smaller, lighter-weight transmission and drive line components. Likewise, the
compounded weight reductions of the body, engine and drivetrain reduce stresses on the
suspension components, steering components, wheels, tires and brakes, allowing further
reductions in the mass of these subsystems. The reductions in unsprung masses such as
brakes, control arms, wheels and tires further reduce stresses in the suspension mounting
points. This produces a compounding effect of ripple effect of possible mass reductions.
A fully loaded tractor-trailer combination can weigh up to 80,000 pounds. Reduction
in overall vehicle weight could enable an increase in freight delivered on a ton-mile basis.
Practically, this enables more freight to be delivered per truck and improves freight
transportation efficiency. In certain applications, heavy trucks are weight-limited (i.e. bulk
cargo carriers), and reduced tractor and trailer weight allows direct increases in the quantity of
material that can be carried.
Mass reduction can be accomplished by proven methods such as:
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• Smart Design: Computer aided engineering (CAE) tools can be used to better
optimize load paths within structures by reducing stresses and bending moments
applied to structures. This allows better optimization of the sectional thicknesses of
structural components to reduce mass while maintaining or improving the function of
the component. Smart designs also integrate separate parts in a manner that reduces
mass by combining functions or the reduced use of separate fasteners.
• Material Substitution: Substitution of lower density and/or higher strength materials
into a design in a manner that preserves or improves the function of the component.
This includes substitution of high-strength steels, aluminum, magnesium or composite
materials for components currently fabricated from mild steel. Mass reduction
through material substitution is currently broadly applied across in both light and
heavy-duty applications in all vehicle subsystems such as aluminum engine block,
aluminum transmission housing, high-strength steel body structure, etc.
• Reduced Powertrain Requirements: Reducing vehicle weight sufficiently can allows
for the use of a smaller, lighter and more efficient engine while maintaining or
increasing work or cargo requirements. The subsequent reduced rotating mass (e.g.,
transmission, driveshafts/halfshafts, wheels and tires) via weight and/or size reduction
of components are made possible by reduced torque output requirements.
Reduced mass in heavy-duty vehicles can benefit fuel efficiency and CO2emissions in
two ways. If a truck is running at its gross vehicle weight limit with high density freight, more
freight can be carried on each trip, increasing the trucks ton-miles per gallon. If the truck is
carrying lower density freight and is below the GVW limit, the total vehicle mass is
decreased, reducing rolling resistance and the power required to accelerate or climb grades.
Mass reduction can be achieved by making components with lighter materials (high
strength steel, aluminum, composites) or by eliminating components from the truck. A
common component-elimination example is to use single wide tires and aluminum rims to
replace traditional dual tires and rims, eliminating eight steel rims and eight tires. Although
many gains have been made to reduce truck mass, many of the features being added to
modern trucks to benefit fuel economy, such as additional aerodynamic features or idle
reduction systems, have the effect of increasing truck weight causing mass to stay relatively
constant. Material and manufacturing technologies can also play a significant role in vehicle
safety by reducing vehicle weight, and in the improved performance of vehicle passive and
active safety systems. Although new vehicle systems, such as hybrid power trains, fuel cells
and auxiliary power will present complex packaging and weight issues, this will further
increase the need for reductions in the weight of the body, chassis, and power train
components in order to maintain vehicle functionality.
EPA's SmartWay transport web page discusses how the truck fuel consumption
increases with the weight of the vehicle. Many truck components are typically made of
heavier material, such as steel. Heavier trucks require more fuel to accelerate and to climb
hills, and may reduce the amount of cargo that can be carried.54 Every 10 percent drop in
truck weight reduces fuel use about 5 percent. Generally, an empty truck makes up about one-
third of the total weight of the truck. Using aluminum, metal alloys, metal matrix composites,
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
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and other lightweight components where appropriate can reduce empty truck weight (known
as "tare weight"), improve fuel efficiency, and reduce greenhouse gas emissions. As an
example, trimming 3,000 pounds from a heavy truck (about 4 percent of its loaded weight)
with lighter-weight components could improve fuel economy by up to 3 percent and trucks
that employ more weight saving options would save more. In addition, in weight-sensitive
applications, lightweight components can allow more cargo and increased productivity.
Another report by the National Commission on Energy Policy estimates that a fuel economy
gain of 5.0 percent on certain applications could be achieved by vehicle mass reduction
further illustrating the fuel economy gains possible on heavy-duty applications55. A third
report, estimated potential reductions in modal GHG emissions are 4.6 percent, however also
states current light-weight materials are costly and are application and vehicle specific with
further research and development for advanced materials are needed.
In support of the overall goal to cost-effectively enable trucks and other heavy
vehicles to be more energy efficient and to use alternative fuels while reducing emissions, the
21st Century Truck Partnership seeks to reduce parasitic energy losses due to the weight of
heavy vehicles without reducing vehicle functionality, durability, reliability, or safety, and to
do so cost-effectively. Aggressive weight reduction goals vary according to the weight class
of the vehicle with targets between 10 and 33 percent. The weight targets for each vehicle
class depend on the performance requirements and duty cycle. It is important to note that
materials or technologies developed for a particular vehicle class are not necessarily limited to
that class. For example, materials developed for lightweight frames for pickup trucks, vans, or
SUVs will eventually be used in Class 3-5 vehicles, and materials developed to meet the
demanding performance requirements for Class 7 and 8 trucks will find application in smaller
vehicles. Weight reduction must not in any way sacrifice the durability, reliability, and
performance of the vehicle. Attaining these goals by reducing inertial loading will yield
substantial benefits such as increased fuel efficiency with concomitant reductions in
emissions, increased available payload capacity for some vehicles, reduced rolling resistance,
and optimized safety structures and aerodynamic drag reduction systems.
A 2009 NESCAFE report evaluated the potential to reduce fuel consumption and CO2
emissions by reducing weight from the baseline weight of 80,000 pounds. For the purpose of
this calculation, the weight reduction could come either from carrying lighter freight or from a
reduction in the empty weight of the truck. If the vehicle mass is reduced to 65,000 pounds,
the fuel economy improves to 5.9 MPG from 5.4 MPG. The fuel savings and CC^reduction on
the baseline vehicle amount to about 0.5 percent per 1,000 pounds of mass reduction. This
result suggests that efforts to reduce the empty vehicle mass will have only a modest benefit
on fuel economy, for long haul routes.
Argonne has also attempted to simulate the effect of mass reduction on the fuel
economy of heavy trucks through the National Renewable Energy Laboratory's Advanced
Vehicle Simulator Model, ADVISOR. The Argonne simulations relied on a few driving
schedules developed by the West Virginia University (WVU) because there are no established
driving schedules for heavy trucks,. While simulating a Class 8 truck on the WVU Intercity
Driving Schedule, a fuel economy gain of 0.6 percent was observed for each 1 percent mass
reduction from 65,000 Ib to 58,000 lb56. The maximum speed during the simulation was 61
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Regulatory Impact Analysis
mph, and the average running speed (excluding stops) was 37.5 mph although most intercity
Class 8 trucks average a much higher speed than 37.5 mph. Argonne assumed a 0.66 percent
increase in fuel economy for each 1 percent weight reduction and total possible estimated fuel
economy increases of 5-10 percent. While simulating a Class 6 truck on a WVU Suburban
Driving Schedule, a fuel economy gain of 0.48 percent was observed for each 1 percent mass
reduction from 22,600 Ib to 21,800 Ib. The maximum speed during the simulation was 44.8
mph, and the average running speed was 21.5 mph. The potential fuel economy gains for
medium trucks, both heavy- and light-, were capped at 5 percent since they are less likely to
be weight or volume limited, and so the use of expensive lightweight material would not be
cost-effective.
The principal barriers to overcome in reducing the weight of heavy vehicles are
associated with the cost of lightweight materials, the difficulties in forming and
manufacturing lightweight materials and structures, the cost of tooling for use in the
manufacture of relatively low-volume vehicles (when compared to automotive production
volumes), and ultimately, the extreme durability requirements of heavy vehicles. While light-
duty vehicles may have a life span requirement of several hundred thousand miles, typical
heavy-duty commercial vehicles must last over 1 million miles with minimum maintenance,
and often are used in secondary applications for many more years. This requires high strength,
lightweight materials that provide resistance to fatigue, corrosion, and can be economically
repaired. Additionally, because of the limited production volumes and the high levels of
customization in the heavy-duty market, tooling and manufacturing technologies that are used
by the automotive industry are often uneconomical for heavy vehicle manufacturers.
Lightweight materials such as aluminum, titanium and carbon fiber composites provide the
opportunity for significant weight reductions, but their material cost and difficult forming and
manufacturing requirements make it difficult for them to compete with low-cost steels. In
addition, although mass reduction is currently occurring on both vocational and line haul
trucks, the addition of other systems for fuel economy, performance or comfort increases the
truck mass offsetting the mass reduction that has already occurred, thus is not captured in the
overall truck mass measurement.
Most truck manufacturers offer lightweight tractor models that are 1,000 or more pounds
lighter than comparable models. Lighter-weight models combine different weight-saving options that
may include:5?
• Cast aluminum alloy wheels can save 40 pounds each for total savings of 400 pounds
• Aluminum axle hubs can save over 120 pounds compared to ductile iron or steel
• Centrifuse brake drums can save nearly 100 pounds compared to standard brake drums
• Aluminum clutch housing can save 50 pounds compared to iron clutch housing
• Composite front axle leaf springs can save 70 pounds compared to steel springs
• Aluminum cab frames can save hundreds of pounds compared to standard steel frames
• Downsizing to a smaller, lighter-weight engine can save over 700 pounds58
2.5.3.1 Derivation of Weight Technology Packages
The agencies see many opportunities for weight reduction in tractors. However, the
empty curb weight of tractors varies significantly today. Items as common as fuel tanks can
vary between 50 and 300 gallons each for a given truck model. Information provided by truck
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
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manufacturers indicates that there may be as much as a 5,000 to 17,000 pound difference in
curb weight between the lightest and heaviest tractors within a regulatory subcategory (such
as Class 8 sleeper cab with a high roof). Because there is such a large variation in the
baseline weight among trucks that perform roughly similar functions with roughly similar
configurations, there is not an effective way to quantify the exact CO2 and fuel consumption
benefit of mass reduction using GEM because of the difficulty in establishing a baseline.
However, if the weight reduction is limited to tires and wheels, then both the baseline and
weight differentials for these are readily quantifiable and well-understood. Therefore, the
agencies are proposing that the mass reduction that would be simulated be limited only to
reductions in wheel and tire weight. The agencies still encourage each OEM to reduce tractor
curb weight in as many other ways as possible, which would reduce emission and fuel
consumption independent of the degree to which such improvements are recognized for fuel
consumption and CC>2 compliance purposes. In the context of this heavy-duty vehicle
program with only changes to tires and wheels, the agencies do not foresee any related impact
on safety.
EPA and NHTSA are proposing to specify the baseline vehicle weight for each
regulatory category (including the tires and wheels), but allow manufacturers to quantify
weight reductions based on the wheel material selection and single wide versus dual tires per
Table 2-20. The agencies assume the baseline wheel and tire configuration contains dual tires
with steel wheels. The proposed weight reduction due to the wheels and tires would be
reflected in the payload tons by increasing the specified payload by the weight reduction
amount discounted by two thirds to recognize that approximately one third of the truck miles
are travelled at maximum payload.
Table 2-20: Proposed Weight Reductions
Single Wide Tire (per tire)
High strength steel dual wheel (per wheel)
Aluminum dual wheel (per wheel)
Light weight aluminum dual wheel (per wheel)
Steel single wide wheel (per wheel)
Aluminum single wide wheel (per wheel)
Light weight aluminum single wide wheel (per wheel)
Weight Reduction (Ib)
57
8
21
30
27
82
90
The agencies have estimated costs for these technologies. Those costs are shown in
Table 2-21. The costs shown include a low complexity ICM of 1.14 and time based learning
would be considered appropriate for these technologies.
Table 2-21 Estimated Weight Reduction Technology Costs for Class 7 & 8 Tractors for the 2014MY
(2008$)
Single Wide Tire (per tire)
Aluminum Steer Wheel
Aluminum Wheels - dual
Aluminum Wheel - Single wide
CLASS 7 TRACTORS
$322
$523
$1,569
$627
CLASS 8 TRACTORS
$644
$523
$2,615
$1,254
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2.5.4 Extended Idle
Class 8 heavy-duty diesel truck extended engine idling wastes significant amounts of
fuel in the United States. Department of Transportation regulations require a certain amount
of rest for a corresponding period of driving hours. Extended idle occurs when Class 8 long
haul drivers rest in the sleeper/cab compartment during rest periods as drivers find it more
convenient and economical to rest in the truck cab itself. In many cases it is the only option
available. During this rest period a driver will idle the truck in order to provide heating or
cooling or run on-board appliances. During rest periods the truck's main propulsion engine is
running but not engaged in gear and it remains in a stationary position. In some cases the
engine can idle in excess of 10 hours. During this period of time, fuel consumption will
generally average 0.8 gallons per hour. Average overnight fuel usage would exceed 8 gallons
in this example. When multiplied by the number of long haul trucks without idle control
technology that operate on national highways on a daily basis the number of gallons
consumed by extended idling would exceed 3 million gallons per day. Fortunately, a number
of alternatives (idling reduction technologies) are available to alleviate this situation.
2.5.4.1 Idle Control Technologies
Idle reduction technologies in general utilize an alternative energy source in place of
operating the main engine. By using these devices the truck driver can obtain needed power
for services and appliances without running the engine. A number of these devices attach to
the truck providing heat, air conditioning, or electrical power for microwave oven, televisions,
etc.
The idle control technologies available today include the following:59
• Auxiliary Power Unit (APU) which powers the truck's heating, cooling, and
electrical system. The fuel use of an APU is typically 0.2 gallons per hour
• Fuel Operated Heater (FOH) provides heating services to the truck through
small diesel fired heaters. The fuel use is typically 0.04 gallons per hour.
• Battery Air Conditioning Systems (BAG) provides cooling to the truck.
• Thermal Storage Systems provide cooling to trucks.
Another alternative involves electrified parking spaces (EPS) with or without
modification to the truck. An EPS system operates independently of the truck's engine and
allows the truck engine to be turned off as the EPS system supplies heating, cooling, and
electrical power. The EPS system provides off-board electrical power to operate either:
1. A single system electrification requires no on-board equipment by providing an
independent heating, cooling, and electrical power system, or
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2. A dual system which allows driver to plug in on-board equipment
In the first case power is provided to stationary equipment that is temporarily attached
to the truck. In the second, the truck is modified to accept power from the electrical grid to
operate on board truck equipment. The retail price of idle reduction systems varies depending
on the level of sophistication, for example, on-board technologies such as APUs can retail for
over $7,000 while options such as EPS require negligible up-front costs for equipment for the
truck itself, but will accrue fees with usage.
2.5.4.2 CO2 g/ton-mile Idle Reduction Benefit
CC>2 emissions during extended idling are a significant contributor to Class 8 sleeper
cabs. The federal test procedure does evaluate idle emissions as part of the drive cycle and
related emissions measurement. However, long duration extended idle emissions are not fully
represented during the prescribed test cycle. Consequently, there is an opportunity to
recognize the CC>2 reductions attributed to idle control systems by employing a credit
mechanism for manufacturers who provide for idle control devices in the original truck/
tractor build or in the case of EPS provide a pre-purchase plan for EPS facility use and install
all necessary equipment on the tractor. The credit would allow truck manufacturers additional
flexibility in product design and performance capabilities as the CC>2 requirements are put in
place.
Truck owners can obtain verified idle reduction technologies on a new truck at the
time of purchase from the manufacturer or retrofit with verified technology after purchase
provided a retrofit agreement is in place prior to introduction into commerce. For a
manufacturer to qualify for the reduction, the agencies are proposing that a truck have an
automatic engine shut-off system that shuts off the engine after five minutes of idling when it
is in a parked position. This approach allows for operational strategies such as electrified
parking spaces, team drivers, and overnights spent in hotels to achieve and idle reduction
while still being tied back to a verifiable technology (i.e., engine shutoff).
Idle reduction credits would be based on the GHG emission and fuel consumption
reduction from the technology when compared to main engine idling, as shown in Table 2-22.
The main engine consumes approximately 0.8 gallons per hour during idling.60 Using a factor
of 10,180 grams of CC>2 per gallon of diesel fuel, the CO2 emissions from the main engine at
idle is 8,144 g per hour. The agencies assumed the average Class 8 sleeper cab spends 1,800
hours in extended idle per year to determine the idling emissions per year.61 The agencies
then assumed the average Class 8 sleeper cab travels 125,000 miles per year (500 miles per
day and 250 days per year) and carries 19 tons of payload (the standardized payload proposed
for Class 8 tractors) to calculate the baseline emissions as 6.2 grams of CC>2 per ton-mile.
The engine used to power the APU consumes an approximately 0.2 gallons of diesel
fuel per hour.6 The CC>2 emissions from the APU equate to 1.5 grams per ton-mile.
Therefore, the agencies are proposing an idle reduction credit 5 g CO2 per ton-mile which
represents the difference in emissions between the main engine idling and idling with an
APU. Credits as proposed are based on the requirement that all Class 8 sleeper cabs shall be
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Regulatory Impact Analysis
equipped with and automatic engine shut-off. The credit reflects a technology's fuel
consumption in conjunction with a shut-off
Table 2-22: Idle Credit Calculation
Baseline
Idle
Reduction
Technology
Idle Fuel
Consumption
(gal/hour)
0.8
0.2
Idle CO2
emissions
per hour
8,144
2,036
Idle
Hours
per
Year
1,800
1,800
Idle CO2
Emission
per year
(grams)
14,659,20
0
3,664,800
Miles
Per
Year
125,000
125,000
Payload
(tons)
19
19
GHG
Emissions
due to Idling
(g/ton-mile)
6.2
1.5
GHG
Reduction
(g/ton-
mile)
5
Fuel
Consumption
Reduction
(gal/100 ton-
mile)
0.05
2.5.5 Vehicle Speed Limiters
As discussed above, the power required to move a vehicle increases as the vehicle
speed increases. Travelling at lower speeds provides additional efficiency to the vehicle
performance. Most vehicles today have the ability to electronically control the maximum
vehicle speed through the engine controller. This feature is used today by fleets and owners
to provide increased safety and fuel economy. Currently, these features are able to be
changed by the owner and/or dealer.
The impact of this feature is dependent on the difference between the governed speed
and the speed that would have been travelled, which is dependent on road type, state speed
limits, traffic congestion, and other factors. EPA will be assessing the benefit of a vehicle
speed limiter by reducing the maximum drive cycle speed on the 65 mph Cruise mode of the
cycle. The maximum speed of the drive cycle is 65 mph, therefore any vehicle speed limit
with a setting greater than this will show no benefit for regulations, but may still show benefit
in the real world in states where the interstate truck speed limit is greater than the national
average of 65.5 mph.
The benefits of this simple technology are widely recognized. The American
Trucking Association (ATA) developed six recommendations to reduce carbon emissions
from trucks in the United States. Their first recommendation is to enact a national truck speed
limit of 65 mph and require that trucks manufactured after 1992 have speed governors set at
not greater than 65 mph.63 The SmartWay program includes speed management as one of
their key Clean Freight Strategies and provides information to the public regarding the benefit
of lower highway speeds.64
Some countries have enacted regulations to reduce truck speeds. For example, the
United Kingdom introduced regulations in 2005 which require new trucks used for goods
movement to have a vehicle speed limiter not to exceed 90 kph (56 mph).65 The Canadian
Provinces of Ontario and Quebec developed regulations which took effect in January 2009
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that requires on-highway commercial heavy-duty trucks to have speed limiters which limit the
truck's speed to 105 km/h.66
Many truck fleets consider speed limiter application a good business practice in their
operations. A Canadian assessment of heavy-duty truck speed limiters estimated that 60
percent of heavy truck fleets in North America use speed limiters.67 Con Way Freight, Con
Way Truckload, and Wal-Mart currently govern the speeds of their fleets between 62 and 65
mph.68
A potential disbenefit of this technology is the additional time required for goods
movement, or loss of productivity. The elasticity between speed reduction and productivity
loss has not been well defined in industry. The Canadian assessment of speed limiters found
that the fuel savings due to the lower operating speeds outweigh any productivity losses. A
general consensus among the OEMs is that a one percent decrease in speed might lower
productivity by approximately 0.2 percent.69
There is no additional capital cost associated with a vehicle speed limiter. There are
no hardware requirements for this feature, only software control strategies. Nearly all heavy-
duty engines today are electronically controlled and are capable of being programmed for a
maximum vehicle speed. The only new requirement for truck manufacturers is to offer a
vehicle speed limiter which is protected from tampering and cannot be changed by the fleet or
truck owner. This technology is required to be used for the full useful life of the vehicle to
obtain the GHG emissions reduction.
The vehicle speed limiter is applicable to all truck classes which operate at high
speeds. However, due to the structure of the first phase of the Heavy-Duty truck program, it
is only applicable to the Class 7-8 tractors. The benefits of the vehicle speed limiter are
assessed through the use of alternate High Speed Cruise cycles. The baseline cycle contains a
constant 65 mph cruise.
2.5.6 Automated Manual Transmission
Most heavy-duty trucks use manual transmissions with 8 to 18 ratios available. The
most common transmissions for line haul applications have 10 ratios with an overdrive top
gear. Torque-converter automatic transmissions, similar to those used in passenger cars, are
used in some stop/go truck applications but are more expensive do not have an efficiency
advantage in line-haul applications. Automated manual transmissions have been available on
the market for over 10 years now and are increasing in market share. Automated manuals
have a computer to decide when to shift and use pneumatic or hydraulic mechanisms to
actuate the clutch and hidden shift levers. An automated manual can shift as quickly as the
best driver, and the shift schedule can be tailored to match the characteristics of the engine
and vehicle. This reduces variability of fuel consumption and CO2 emissions between drivers,
with all drivers achieving results closer to those of the best drivers. In application, there
would be a fuel economy improvement proportional to the number of non-fuel-conscious
drivers in a fleet. [Reducing Heavy-Duty Long Haul Combination Truck Fuel Consumption
and CO2 Emissions, NESCCAF/ICCT Final Report, October, 2009]
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Regulatory Impact Analysis
2.5.7 Class 7-8 Tractor Baseline Assessment
The agencies developed the baseline tractor for each subcategory to represent an
average 2010 model year tractor. The approach taken by the agencies was to define the
individual inputs to GEM. For example, the agencies evaluated the industry's tractor
offerings and conclude that the average tractor contains a generally aerodynamic shape (such
as roof fairings) and avoid classic features such as exhaust stacks at the b-pillar which
increase drag. The agencies consider a baseline truck as having "conventional"
aerodynamics. The baseline rolling resistance coefficient for today's fleet is 7.8 kg/metric ton
for the steer tire and 8.2 kg/metric ton for the drive tire, based on sales weighting of the top
three manufacturers based on market share.70 However, today there is a large spread in
aerodynamics in the new tractor fleet. Trucks are sold that reflect classic styling, or are sold
with conventional or SmartWay aerodynamic packages.
Table 2-23 Class 7 and 9 Baseline Attributes
Class 7
Day Cab
Low/Mid
Roof
High Roof
Class 8
Day Cab
Low/Mid
Roof
High Roof
Sleeper Cab
Low Roof
Mid Roof
High Roof
Aerodynamics (Cd)
Frontal Area (m^)
Baseline
6.0
0.81
9.8
0.69
6.0
0.81
9.8
0.69
6.0
0.81
7.7
0.76
9.8
0.69
Steer Tires (Crr kg/metric ton)
Baseline
7.8
7.8
7.8
7.8
7.8
7.8
7.8
Drive Tires (Crr kg/metric ton)
Baseline
8.2
8.2
8.2
8.2
8.2
8.2
8.2
Weight Reduction (Ibs.)
Baseline
0
0
0
0
0
0
0
Extended Idle Reduction (gram CO2/ton-mile reduction)
Baseline
N/A
N/A
N/A
N/A
0
0
0
Vehicle Speed Limiter
Baseline
-
-
-
-
-
-
-
2.5.8 Class 7-8 Tractor Standards Derivation
EPA and NHTSA project that CC>2 emissions and fuel consumption reductions can be
achieved through the increased penetration of aerodynamic technologies, low rolling
resistance tires, weight reduction, extended idle reduction technologies, and vehicle speed
limiters. The agencies believe that hybrid powertrains in line haul applications will not be
cost effective in the time frame of the rule. The agencies also are proposing to not include
drivetrain technologies in the standard setting process, as discussed in Section II, instead are
choosing to allow the continuation of the current truck specifying process that is working well
today.
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The agencies started with a goal of essentially forcing SmartWay technologies
(aerodynamics, tires, and extended idle) into 100 percent of Class 7 and Class 8 tractors.
However, as discussed below, the agencies realize that there are some restrictions which
prevent 100 percent penetration. Therefore, the agencies took the approach of evaluating each
technology and proposing what we deem as the maximum feasible penetration into each
tractor regulatory category. The next sections describe the effectiveness of the individual
technologies, the costs of the technologies, the proposed penetration rates of the technologies
into the regulatory categories, and finally the derivation of the proposed standards.
2.5.8.1 Technology Effectiveness
The agencies' assessment of the proposed technology effectiveness was developed
through the use of the GEM Model in coordination with chassis testing of three SmartWay
certified Class 8 sleeper cabs. The agencies are projecting the following tire rolling resistance
performance for setting the proposed tractor standards, as shows in Table 2-19. Table 2-24
describes the proposed model inputs for the range of Class 7 and 8 tractor technologies.
Table 2-24: GEM Inputs
Class 7
Day Cab
Low Roof
High Roof
Class 8
Day Cab
Low Roof
High Roof
Sleeper Cab
Low Roof
Mid Roof
High Roof
Aerodynamics (Cd)
Frontal Area (m^)
Classic
Conventional
SmartWay
Advanced SmartWay
Advanced SmartWay II
6.0
0.85
0.80
0.75
0.70
0.65
9.8
0.75
0.68
0.60
0.55
0.50
6.0
0.85
0.80
0.75
0.70
0.65
9.8
0.75
0.68
0.60
0.55
0.50
6.0
0.85
0.80
0.75
0.70
0.65
7.7
0.80
0.75
0.70
0.65
0.60
9.8
0.75
0.68
0.60
0.55
0.50
Steer Tires (Crr kg/metric ton)
Baseline
SmartWay
Advanced SmartWay
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
7.8
6.6
5.7
Drive Tires (Crr kg/metric ton)
Baseline
SmartWay
Advanced SmartWay
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
8.2
7.0
6.0
Weight Reduction (Ibs.)
Control
400
400
400
400
400
400
400
Extended Idle Reduction (gram CO2/ton-mile reduction)
Control
N/A
N/A
N/A
N/A
5
5
5
Vehicle Speed Limiter
Control
N/A
N/A
N/A
N/A
N/A
N/A
N/A
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Regulatory Impact Analysis
2.5.8.2 Class 7-8 Tractor Application Rates
Vehicle manufacturers often introduce major product changes together, as a package.
In this manner the manufacturers can optimize their available resources, including
engineering, development, manufacturing and marketing activities to create a product with
multiple new features. In addition, manufacturers recognize that an engine and truck will
need to remain competitive over its intended life and meet future regulatory requirements. In
some limited cases, manufacturers may implement an individual technology outside of a
vehicle's redesign cycle. In following with these industry practices, the agencies have created
a set of vehicle technology packages for each regulatory subcategory.
With respect to the level of technology required to meet the standards, NHTSA and
EPA established technology application caps. The first type of cap was established based on
the application of common fuel consumption and CC>2 emission reduction technologies into
the different types of tractors. For example, idle reduction technologies are limited to Class 8
sleeper cabs using the assumption that day cabs are not used for overnight hoteling. A second
type of constraint was applied to most other technologies and limited their penetration based
on factors such as market demands.
The impact of aerodynamics on a truck's efficiency increases with vehicle speed.
Therefore, the usage pattern of the truck will determine the benefit of various aerodynamic
technologies. Sleeper cabs are often used in line haul applications and drive the majority of
their miles on the highway travelling at speeds greater than 55 mph. The industry has focused
aerodynamic technology development, including SmartWay certified tractors, on these types
of trucks. Therefore the agencies are proposing the most aggressive aerodynamic technology
penetration in this regulatory subcategory. All of the major manufacturers today offer at least
one truck model that is SmartWay certified. The National Academy of Sciences report on
heavy-duty truck found that manufacturers indicated that aerodynamic improvements which
yield 3 to 4 percent fuel consumption reduction or 6 to 8 percent reduction in Cd values,
beyond technologies used in today's SmartWay trucks are achievable.71 EPA and NHTSA
are proposing that the aerodynamic penetration rate for Class 8 sleeper cab high roof cabs to
consist of 20 percent of advanced SmartWay, 70 percent SmartWay, and 10 percent
conventional. The small percentage of conventional truck aerodynamics is for applications
such as refuse haulers which spend a portion of their time off-road at the land fill. Features
such as chassis skirts are prone to damage in off-road applications; therefore we are not
proposing to require that all trucks have chassis skirts.
The aerodynamic penetration for the other tractor regulatory subcategories is less
aggressive than for the Class 8 sleeper cab high roof. The agencies acknowledge that there
are truck applications which require on/off-road capability and other truck functions which
restrict the type of aerodynamic equipment applicable. We also recognize that these types of
trucks spend less time at highway speeds where aerodynamics have the greatest benefit. The
2002 Vehicle Inventory and Use Survey (VIUS) data ranks trucks by major use.72 The heavy
trucks usage indicates that up to 35 percent of the trucks may be used in on/off-road
applications or heavier applications. The uses include construction (16 percent), agriculture
(12 percent), waste management (5 percent), and mining (2 percent). Therefore the agencies
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analyzed the technologies to evaluate the potential restrictions that would prevent 100 percent
penetration of SmartWay technologies for all of the tractor regulatory subcategories.
Trucks designed for on/off-road application may be restricted in the ability to improve
the aerodynamic design of the bumper, chassis skirts, air cleaners, and other aspects of the
truck. First, off-road applications may require the use of steel bumpers which tend to be less
aerodynamic than plastic designs. Second, ground clearance may be an issue for some off
road applications due to poor road surface quality. This may pose a greater likelihood those
items such as chassis skirts incur damage in use and therefore would not be a technology
desirable in these applications. Third, the trucks used in off-road applications may also
experience dust which requires an additional air cleaner to manage the dirt. Fourth, some
trucks are used in applications which require heavier load capacity, such as those with gross
combined weights of greater than 80,000 pounds, which is today's federal highway limit.
Often these trucks are configured with different axle combinations than those traditionally
used on-road. These trucks may contain either a lift axle or spread axle which allows for
greater carrying capability. Both of these configurations limit the design and effectiveness of
chassis skirts. Lastly, some work trucks require the use of power take off (PTO) operation or
access to equipment which may limit the application of side extenders and chassis skirts.
NHTSA and EPA have considered these potential restrictions while developing the
proposed maximum penetration rate of each of the aerodynamic bins for the Class 7 and 8
tractors. The high roof applications are designed for more highway driving and pulling box
trailers. Therefore, they have the greatest penetration rates. However, truck buyers will
typically purchase low roof cabs to handle the on/off-road or heavier applications. Therefore,
the penetration rates are lower for these segments.
Tire rolling resistance is only one of several performance criteria that affect tire
selection. The characteristics of a tire also influence durability, traction control, vehicle
handling and comfort. A single performance parameter can easily be enhanced, but an
optimal balance of all the criteria must be maintained. Tire design requires balancing
performance, since changes in design may change different performance characteristics in
opposing direction. Similar to the discussion regarding lesser aerodynamic technology
penetration in tractor segments other than sleeper cab high roof, the agencies believe that low
rolling resistance tires should not be applied to 100 percent of all tractor segments. The
agencies are proposing application rates that vary by subcategory to reflect the on/off-road
application of some tractors which require a different balancing of traction versus rolling
resistance.
Weight reductions can be achieved through single wide tires replacing dual tires and
lighter weight wheel material. Single wide tires can reduce weight by over 160 pounds per
axle. Aluminum wheels used in lieu of steel wheels will reduce weight by over 80 pounds for
a dual wheel axle. Light weight aluminum steer wheels and aluminum single wide drive
wheels and tires package will provide a 670 pound weight reduction over the baseline steel
steer and dual drive wheels. The agencies are proposing 100 percent penetration of a
technology package which reduces vehicle weight by 400 pounds.
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Idle reduction technologies provide significant reductions in fuel consumption and
CC>2 emissions. There are several different technologies available to reduce idling. Auxiliary
power units, diesel fired heaters, and battery powered units. Each of these technologies has a
different level of fuel consumption and CO 2 emissions. Therefore, the emissions reduction
value varies by technology. Also, our discussions with manufacturers indicate that idle
technologies are sometimes installed in the factory, but it is also a common practice to have
the units installed after the sale of the truck. Therefore, we would like to continue to
incentivize this practice while providing some certainty that the overnight idle operations will
be eliminated. Therefore, we are allowing the installation of only an automatic engine
shutoff, without override capability, to qualify for idle emission reductions. We are proposing
a 100 percent penetration rate for this technology and have estimated that 30 percent of the
current fleet already employs this technology meaning that 70 percent are estimated to add
this technology.
Vehicle speed limiters will be used as a technology to meet the standard, but was not
used to set the standard. The agencies do not want to create the perception of setting a
national speed limit for trucks. While we believe this is a simple, easy to implement, and
inexpensive technology, we want to leave the use up to the truck purchaser. Since truck fleets
purchase trucks today with this option, we believe the trend will continue. However, we
cannot predict the impact of this technology on the resale value of the truck and the decreased
productivity, therefore we leave it to the purchasers to optimize the use of speed limiters
based on the fuel savings relative to impact on business operations and resale value.
Table 2-25 provides the proposed application rates for each technology by regulatory
sub category.
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Table 2-25: Proposed Application Rates
Class 7
Day Cab
Low/Mid
Roof
High Roof
Class 8
Day Cab
Low/Mid
Roof
High Roof
Sleeper Cab
Low Roof
Mid Roof
High Roof
Aerodynamics (Cd)
Classic
Conventional
SmartWay
Advanced
SmartWay
Advanced
SmartWay II
0%
40%
50%
10%
0%
0%
30%
60%
10%
0%
0%
40%
50%
10%
0%
0%
30%
60%
10%
0%
0%
30%
60%
10%
0%
10%
20%
60%
10%
0%
0%
10%
70%
20%
0%
Steer Tires (Crr kg/metric ton)
Baseline
SmartWay
Advanced
SmartWay
40%
50%
10%
30%
60%
10%
40%
50%
10%
30%
60%
10%
30%
60%
10%
30%
60%
10%
10%
70%
20%
Drive Tires (Crr kg/metric ton)
Baseline
SmartWay
Advanced
SmartWay
40%
50%
10%
30%
60%
10%
40%
50%
10%
30%
60%
10%
30%
60%
10%
30%
60%
10%
10%
70%
20%
Weight Reduction (Ibs.)
Control
100%
100%
100%
100%
100%
100%
100%
Extended Idle Reduction (gram CO2/ton-mile reduction)
Control
Not
Applicable
Not
Applicable
Not
Applicable
Not
Applicable
100%
100%
100%
Vehicle Speed Limiter
Control
-
-
-
-
-
-
-
The agencies used the technology inputs and proposed technology application rates in
GEM to develop the fuel consumption and CO2 emissions standards for each subcategory of
Class 7/8 combination tractors. The agencies derived a scenario truck for each subcategory
by weighting the individual GEM input parameters included in Table 2-24 by the application
rates in Table 2-25. For example, the Cd value for a Class 8 Sleeper Cab High Roof scenario
case was derived as 10 percent times 0.68 plus 70 percent times 0.60 plus 20 percent times
0.55, which is equal to a Cd of 0.60. Similar calculations were done for tire rolling resistance,
weight reduction, idle reduction, and vehicle speed limiters. To account for the two proposed
engine standards, EPA is proposing the use of a 2014 model year fuel consumption map in
GEM to derive the 2014 model year tractor standard and a 2017 model year fuel consumption
map to derive the 2017 model year tractor standard.73 The agencies then ran GEM with a
single set of vehicle inputs, as shown in Table 2-26, to derive the proposed standards for each
subcategory. The proposed standards and percent reductions are included in Table 2-27.
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Table 2-26 Inputs to the GEM model for Class 7/8 Standard Setting
Aerodynamics (Cd)
Steer Tire CRR
(kg/metric ton)
Drive Tire CRR
(kg/metric ton)
Weight Reduction (Ibs.)
Extended Idle Reduction
(g/ton-mile)
Vehicle Speed Limiter
Class 7
Day Cab
Low/Mid
Roof
0.77
6.99
7.38
400
—
-
High Roof
0.62
6.87
7.26
400
—
-
Class 8
Day Cab
Low/Mid
Roof
0.77
6.99
7.38
400
~
-
High Roof
0.62
6.87
7.26
400
~
-
Sleeper Cab
Low Roof
0.76
6.87
7.26
400
5
-
Mid Roof
0.72
6.87
7.26
400
5
-
High Roof
0.60
6.54
6.92
400
5
-
2014 MY Proposed Standard
Engine
201 4 MY
11L
201 4 MY
11L
201 4 MY
15L
201 4 MY
15L
201 4 MY
15L
201 4 MY
15L
201 4 MY
15L
2017 MY Proposed Standard
Engine
201 7 MY
11L
201 7 MY
11L
201 7 MY
15L
201 7 MY
15L
201 7 MY
15L
201 7 MY
15L
201 7 MY
15L
Table 2-27 Proposed Tractor Standards and Percent Reductions
Class 7
Day Cab
Low/Mid
Roof
High Roof
Class 8
Day Cab
Low/Mid
Roof
High Roof
Sleeper Cab
Low Roof
Mid Roof
High Roof
201 4 Model Year
201 4 MY Voluntary Fuel
Consumption Standard
(gallon/1 000 ton-mile)
201 4 MY C02 Standard
(grams CO2/ton-mile)
Percent Reduction
10.3
104
6%
11.6
118
9%
7.8
79
6%
8.6
87
9%
6.3
65
15%
6.9
70
14%
7.1
73
18%
201 7 Model Year
201 7 MY Fuel
Consumption Standard
(gallon/1 000 ton-mile)
201 7 MY C02 Standard
(grams CO2/ton-mile)
Percent Reduction
10.1
103
7%
11.4
116
11%
7.7
78
7%
8.5
86
10%
6.3
64
16%
6.8
69
15%
7.0
71
20%
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2.5.9 Class 7-8 Tractor Technology Costs
The technology costs associated with the tractor defined in Table 2-26 for each of the
tractor subcategories are listed in Table 2-28.
Table 2-28 Estimated Class 7-8 Tractor Technology Costs, Inclusive of Markups and Penetration Rates,
Applicable in the 2014MY (2008 dollars)
Class 7
Day Cab
Low Roof
High Roof
Class 8
Day Cab
Low Roof
High Roof
Sleeper Cab
Low Roof
Mid Roof
High Roof
Aerodynamics
SmartWay & Advanced
SmartWay
$975
$1,216
$647
$1,215
$1,025
$1,152
$1,527
Steer Tires
Low Rolling Resistance
$65
$65
$65
$65
$65
$65
$65
Drive Tires
Low Rolling Resistance
$60
$60
$121
$121
$121
$121
$121
Weight Reduction
Control
$1,472
$1,472
$2,421
$2,421
$2,421
$2,421
$2,421
Extended Idle Reduction
Auxiliary Power Unit
N/A
N/A
N/A
N/A
$3,660
$3,660
$3,660
Vehicle Speed Limiter
Control
N/A
N/A
N/A
N/A
N/A
N/A
N/A
2.6 Class 2b-8 Vocational Vehicles
2.6.1 Tires
The range of rolling resistance of tires used on vocational vehicles (Class 2b - 8)
today is large. The competitive pressure to improve rolling resistance of these tires has been
less than that found in the Class 8 line haul tire market. Due to the drive cycles typical for
these applications, tire traction and durability are weighed more heavily in a purchaser's
decision than rolling resistance. Therefore, EPA believes that a regulatory program that
incentivizes the optimization of tire rolling resistance, traction and durability can bring about
GHG emission reductions from this segment. It is estimated that low rolling resistance tires
used on Class 3-6 trucks would improve fuel economy by 2.5 percent56 relative to tires not
designed for fuel efficiency.
Tires used on vocational vehicles (Class 2b - 8) typically carry less load than a Class 8
line haul vehicle. They are also designed for instances of high scrubbing. Because they carry
less load and high scrubbing, tires used on vocational vehicles are can retreaded as many as
five times.
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The baseline tire rolling resistance for this segment of vehicles was derived for the
proposal based on the current baseline tractor74 and passenger car tires.75 The baseline tractor
drive tire has a rolling resistance of 8.2 kg/metric ton. The average passenger car has a tire
rolling resistance of 9.75 kg/metric ton. EPA and NHTSA derived the vocational vehicle tire
baseline rolling resistance from the average of these two values. EPA is conducting an
extensive tire rolling resistance evaluation during 2010 and anticipates that the baseline value
will be updated for the final rulemaking based on the results.
The agencies have estimated the costs of low rolling resistance tires as shown in Table
2-29. These costs include a low complexity ICM of 1.14 and time based learning would be
considered appropriate for these technologies.
Table 2-29 Estimated Costs for Low Rolling Resistance Tires on Vocational Vehicles in the 2014MY
(2008$)
Low rolling resistance steer tires
Low rolling resistance drive tires
LIGHT-HEAVY &
MEDIUM-HEAVY
$65
$91
HEAVY-HEAVY
$65
$121
2.6.2 Other Evaluated Technologies
2.6.2.1 Aerodynamics
Aerodynamic drag is an important aspect of the power requirements for Class 2b
through 8 vocational vehicles. Because aerodynamic drag is a function of the cube of vehicle
speed, small changes in the aerodynamics of a vocational vehicle reduces drag, fuel
consumption, and GHG emissions. The great variety of applications for vocational vehicles
result in a wide range of operational speed profiles (i.e., in-use drive cycles) with many
weighted toward lower speeds where aerodynamic improvement benefits are less pronounced.
In addition, vocational vehicles have a wide variety of configurations (e.g., utility trucks with
aerial devices, transit buses, and pick-up and delivery trucks) and functional needs (e.g.,
ground clearance, towing, and all weather capability). This specialization can make the
implementation of aerodynamic features impractical and, where specialty markets are limited,
make it unlikely that per-unit costs will lower with sales volume.
This technology is not expected as a result of the proposed standards.
2.6.2.2 Hybrid Powertrains
A hybrid electric vehicle (HEV) is a vehicle that combines two or more sources of
propulsion energy, where one uses a consumable fuel (i.e. gasoline or diesel), and one is
rechargeable (during operation, or by another energy source). Hybrid technology is
established in the U.S. market and more manufacturers are adding hybrid models to their
lineups. Hybrids reduce fuel consumption through three major mechanisms:
• Powertrain control strategy can be developed to operate the engine at or near its
most efficient point most of the time.
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• The internal combustion engine can be optimized through downsizing or
modifying the operating cycle. Power loss from engine downsizing can be
mitigated by employing power assist from the secondary power source.
• Some of the energy normally lost as heat while braking can be captured and stored
in the energy storage system for later use.
• The engine is turned off when it is not needed, such as when the vehicle is coasting
or stopped, such as extending idle conditions.
Hybrid vehicles utilize some combination of the three above mechanisms to reduce
fuel consumption and CC>2 emissions. A fourth mechanism to reduce fuel consumption,
available only to plug-in hybrids, is by substituting the petroleum fuel energy with energy
from another source, such as the electric grid. Plug-in hybrids may be suitable for some
applications which travel short distances such as local pickup and delivery.
The effectiveness of fuel consumption and CO2 reduction depends on the utilization of
the above mechanisms and how aggressively they are pursued. One area where this variation
is particularly prevalent is in the choice of engine size and its effect on balancing fuel
economy and performance. Some manufacturers choose not to downsize the engine when
applying hybrid technologies depending on the power from the hybrid system components. In
these cases, performance is improved, while fuel efficiency improves significantly less than if
the engine was downsized to maintain the same performance as the conventional version.
While this approach has been used in passenger cars it is more likely to be used for trucks
where towing, hauling and/or cargo capacity is an integral part of their performance
requirements. In these cases, if the engine is downsized, the battery can be quickly drained
during a long hill climb with a heavy load, leaving only a downsized engine to carry the entire
load. Because cargo capability is critical truck attribute, manufacturers are hesitant to offer a
truck with downsized engine which can lead to a significantly diminished towing performance
with a low battery, and therefore engines are traditionally not significantly downsized for
these vehicles.
In addition to the purely hybrid technologies, which decreases the proportion of
propulsion energy coming from the fuel by increasing the proportion of that energy coming
from electricity, there are other steps that can be taken to improve the efficiency of auxiliary
functions (e.g., power-assisted steering or air-conditioning) which also reduce CC>2 emissions
and fuel consumption. Optimization of the auxiliary functions, together with the hybrid
technologies, is collectively referred to as vehicle or accessory load electrification because
they generally use electricity instead of engine power. Fuel efficiency gains achieved only
electrification is considered in a separate section although may be combined with the hybrid
system.
A hybrid drive unit is complex and consists of discrete components such as the electric
traction motor, transmission, generator, inverter, controller and cooling devices. Certain types
of drive units may work better than others for specific vehicle applications or performance
requirements. Several types of motors and generators have been proposed for hybrid-electric
drive systems, many of which merit further evaluation and development on specific
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Regulatory Impact Analysis
applications. Series HEVs typically have larger motors with higher power ratings because the
motor alone propels the vehicle, which may be applicable to Class 3-5 applications. In parallel
hybrids, the power plant and the motor combine to propel the vehicle. Motor and engine
torque are usually blended through couplings, planetary gear sets and clutch/brake units. The
same mechanical components that make parallel heavy-duty hybrid drive units possible can
be designed into series hybrid drive units to decrease the size of the electric motor(s) and
power electronics.
An electrical energy storage system is needed to capture energy from the generator, to
store energy captured during vehicle braking events, and to return energy when the driver
demands power. This technology has seen a tremendous amount of improvement over the last
decade and recent years. Advanced battery technologies and other types of energy storage are
emerging to give the vehicle its needed performance and efficiency gains while still providing
a product with long life. The focus on the more promising energy storage technologies such as
nickel metal-hydride (NiMH) and lithium technology batteries along with ultra capacitors for
the heavy-duty fleet should yield interesting results after further research and applications in
the light-duty fleet.
Heavy-duty hybrid vehicles also use regenerative braking for improved fuel economy,
emissions, brake heat, and wear. A conventional heavy vehicle relies on friction brakes at the
wheels, sometimes combined with an optional engine retarder or driveline retarder to reduce
vehicle speed. During normal braking, the vehicle's kinetic energy is wasted when it is
converted to heat by the friction brakes. The conventional brake configuration has large
components, heavy brake heat sinks, and high temperatures at the wheels during braking,
audible brake squeal, and consumable components requiring maintenance and replacement.
Hybrid electric systems recover some of the vehicle's kinetic energy through regenerative
braking, where kinetic energy is captured and directed to the energy storage system. The
remaining kinetic energy is dissipated through conventional wheel brakes or in a driveline or
transmission retarder. Regenerative braking in a hybrid electric vehicle can require integration
with the vehicle's foundation (friction) braking system to maximize performance and safety.
Today's systems function by simultaneously using the regenerative features and the friction
braking system, allowing only some of the kinetic energy to be saved for later use. Optimizing
the integration of the regenerative braking system with the foundation brakes will increase the
benefits and is a focus for continued work. This type of hybrid regenerative braking system
improves fuel economy, GHG emissions, brake heat, and wear.
In addition to electric hybrid systems, EPA is experimenting with a Class 6 hydraulic
hybrid that achieves a fuel economy increase superior to that of an electric hybrid.76 In this
type of system, deceleration energy is taken from the drivetrain by an inline hydraulic
pump/motor unit by pumping hydraulic fluid into high pressure cylinders. The fluid, while not
compressible, pushes against a membrane in the cylinder that compresses an inert gas to 5,000
PSI or more when fully charged. Upon acceleration, the energy stored in the pressurized tank
pushes hydraulic fluid back into the drivetrain pump/motor unit, allowing it to motor into the
drivetrain and assist the vehicle's engine with the acceleration event. This heavy-duty truck
hybrid approach has been demonstrated successfully, producing good results on a number of
commercial and military trucks.
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Considering the diversity of the heavy-duty fleet along with the various types of
hybridization, the results are diverse as well. The percentage savings that can be expected
from hybridization is very sensitive to duty cycle. For this reason, analyses and efforts to
promote hybrids often focus on narrow categories of vehicles. For vocational vehicles other
than tractor-trailers, hybrid technologies are promising, because a large fraction of miles
driven by these trucks are local and under stop-and-go conditions. One study claims
hybridization could almost double fuel economy for Class 3-5 trucks and raise Class 6-7 fuel
economy by 71 percent in city driving, at costs that will decline rapidly in the coming years
with the incremental cost of the hybrid vehicles depending on the choice of technology and
the year, the later being a surrogate for progress towards economies of scale and experience
with the technology55. Another Argonne National Lab study considering only truck Classes 2
and 3 indicates possible fuel efficiency gains of 40 percent56. The Hybrid Truck Users Forum
has published a selection of four types as good candidates for hybridization; Class 4-8
Specialty Trucks, including utility and fire trucks; Class 4-6 urban delivery trucks, including
package and beverage delivery; Class 7 and 8 refuse collection; and Class 7 and 8 less-than-
load urban delivery trucks. The average fuel economy increase over the five cycles is 93
percent for the Class 3-4 truck and 71 percent for the Class 6-7 vehicle.
Stop-and-go truck driving includes a fraction of idling conditions during which the
truck base engine consumes fuel but produces no economically useful output (e.g., movement
of goods, or repositioning of the truck to a new location). Hybrid propulsion systems, shut off
the engine under idling conditions or situations of low engine power demand. Trucks that
have high fractions of stop-and-go freight transport activities within their driving cycles, such
as medium-duty package and beverage delivery trucks, are appropriate candidates for
hybridization. Long-haul trucks have a lower proportion of short-term idling or low engine
power demand in their duty cycles because of traffic conditions or frequency stops compared
to medium-duty trucks in local services. Based on the results of hybridization effects
modeling, medium-duty trucks in local service (e.g., delivery) can reduce energy use by 41.5
percent7 . Another 2009 report states that a 10 percent fuel consumption decrease could be
achieved if idle reduction benefits were realized and a 5 percent improvement considering for
on-road only 78.
In heavy-duty hybrid research, the industry role will be represented by the heavy-
hybrid team members (e.g. Allison Transmission, Arvin-Meritor, BAE Systems, and Eaton
Corporation). The Department of Energy is pursuing heavy hybrid research through the
Freedom CAR and Vehicle Technologies Program. The Department of Transportation
(Federal Transit Administration) is playing a role in demonstration of these vehicles for the
transit bus market. The Department of Defense is working with heavy hybrid equipment
suppliers to develop and demonstrate hybrid vehicles for military applications, and has
already made significant investments in hybrid technology to reduce fuel consumption and
improve their ability to travel silently in combat situations. The Environmental Protection
Agency has participated in the heavy hybrid arena through its work on mechanical hybrids for
certain applications as discussed previously. The U.S. Department of Energy's 21st Century
Truck Partnership (21CTP) has established challenging goals for improving fuel economy and
pollutant emissions from heavy-duty vehicles including a diverse set of vehicles ranging from
approximately 8,500 Ib GVW to 100,000+ Ib GVW.
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Regulatory Impact Analysis
In summary, many technologies that apply to cars do not apply to heavy-duty trucks
and there is a common perception that investments in passenger car (light-duty vehicle)
technology can easily benefit heavy-duty trucks. This group of vehicles is very diverse and
includes tractor-trailers, refuse and dump trucks, package delivery vehicles and buses. The
life expectancy and duty cycles for heavy-duty vehicles are about ten times more demanding
than those for light-duty vehicles, technologies and solutions for the fleet must be more
durable and reliable. Although a new generation of components is being developed for
commercial and military HEVs, more research and testing are required.
There are no simple solutions applicable for each heavy-duty hybrid application due to
the large fleet variation. A choice must be made relative to the requirements and priorities for
the application. Challenges in motor subsystems such as gear reductions and cooling systems
must be considered when comparing the specific power, power density, and cost of the motor
assemblies. High speed motors can significantly reduce weight and size, but they require
speed reduction gear sets that can offset some of the weight savings, reduce reliability and add
cost and complexity. Air-cooled motors are simpler and generally less expensive than liquid-
cooled motors, but they will be larger and heavier, and they require access to ambient air,
which can carry dirt, water, and other contaminants. Liquid-cooled motors are generally
smaller and lighter for a given power rating, but they may require more complex cooling
systems that can be avoided with air-cooled versions. Various coolant options, including
water, water-glycol, and oil, are available for liquid-cooled motors but must be further
researched for long term durability. Electric motors, power electronics, electrical safety,
regenerative braking, and power-plant control optimization have been identified as the most
critical technologies requiring further research to enable the development of higher efficiency
hybrid electric propulsion systems.
In addition, because manufacturers will incur expenses in bringing hybrids to market,
and because buyers do not purchase vehicles on the basis of net lifetime savings, the cost-
effectiveness of hybrids may not in itself translate into market success, and measures to
promote hybrids are needed until costs come down. Vocational vehicles have diverse duty
cycles, and they are used to a far greater extent for local trips. Some of the technologies are
much less effective for trucks that generally drive at low speeds and therefore have limited
applicability. Conversely, these trucks are the best candidates for hybrid technology, because
local trips typically involve a large amount of stop-and-go driving, which permits extensive
capture of braking and deceleration energy.
Due to the complexity of the heavy-duty fleet, the variation of hybrid system reported
fuel efficiency gains and the growing research and testing - vehicle hybridization is not
mandated nor included in the model for calculation of truck fuel efficiency and GHG output.
Vehicle hybridization is feasible on both tractor and vocational applications but must be tested
on an individual basis to an applicable baseline to realize the system benefits and net fuel
usage and GHG reductions.
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2.6.2.3 EPA Testing of a Hybrid Transit Bus
EPA conducted a hybrid transit bus test to gather experience in testing hybrids and
evaluate the GHG emissions and fuel consumption benefits. This section provides an
overview of the study and its results.
Following coastdown testing, in-use emissions testing was conducted on each bus
using portable emissions measurement systems meeting subpart J of 40 CFR 1065. Each bus
was operated over two routes, which were meant to simulate normal transit bus operation. The
first route was comprised entirely of typical urban stop/go driving, with a number of bus stops
along the 4.75 mile route. The second route was comprised of roughly half urban driving and
half highway operation, reaching a maximum speed of approximately 60 MPH. This route
was approximately 5.75 miles in length.
Fuel economy could be calculated using two methods: through integration of the
instantaneous fuel rate broadcast by the ECU (ECU method) or through a carbon balance of
the exhaust gases (Carbon Balance Method). Both methods provided repeatable results,
however the ECU method tended to consistently yield approximately 5 percent lower fuel
consumption on both vehicles. This bias appears to be due to small differences in predicted
fuel flow versus measured exhaust carbon, particularly during deceleration where the ECU
predicts a complete fuel cut-off. Since the carbon balance method yields more conservative
results, all fuel consumption data presented has been calculating using this method.
Figure 2-1 presents a comparison of the fuel economy of both buses over the two test
routes. Each vehicle was tested at least 3 times over each route, and in several cases up to 10
repeats of each route were conducted. The error bars represent the standard deviation over the
replicates of each route. Over both routes, the hybrid showed a significant fuel economy
benefit over the conventional bus. Over route 1 (urban only), this benefit was greatest and
approached 37 percent. Over route 2 (mixed urban/highway), fuel economy was still
improved by over 25 percent. Much of this benefit is likely attributable to the regenerative
braking and launch assist capability of the hybrid system since there is no idle shut-off of the
engine. A secondary benefit to the regenerative braking system is a significant increase in
brake service intervals, which was highlighted in discussions with a bus fleet operator.
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Figure 2-1 Hybrid and Conventional Bus Fuel Economy (mpg)
Fuel Economy vs Route DConventional
OQ DHvbrid
CD
Q.
O
o 40-
o
LU
P 30
2 0 -
nn -
7.04
T
5.15
r-\—
1
1
5.52
T
1
6.95
rh
Route 1
Route 2
Figure 2-2 presents the CC>2 emissions over each route on a work-specific basis. For
comparison, Figure 2-3, presents CC>2 normalized by the mileage travelled. Characterizing the
CO2 reduction due to the hybrid system, both methods show significant decreases in
emissions. The work-specific basis may provide a more accurate comparison in this case,
since environmental effects are better accounted for (i.e. driver aggressiveness, traffic, etc).
This is evident when comparing the variation over the course of testing, represented by the
standard deviation. The variability on a work-specific basis is nearly half that of using the
distance-based metric.
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Figure 2-2 Hybrid and Conventional Bus CO2 Emission Rates (g/bhp-hr)
CO2 Emissions vs Route
700 -i
.c
S
CM
n -
624
T
1
396
^
602
T
1
nrv
• Hy
410
E 1
nventional
brid
Route 1
Route 2
Figure 2-3 Hybrid and Conventional Bus CO2 Emission Rates (g/mile)
CO2 Emissions vs Route
2500
Route 1
Route 2
Figure 2-4 (a-d) compares the CO2 emissions rate (in g/s) during typical launch
(starting from a stop) events in both buses. Both vehicles showed a spike in CC>2 emissions
when starting from a stop. However, this spike was much more attenuated with the hybrid
bus, which demonstrates the ability of the launch assist system to reduce CC>2 emissions. The
magnitude of this attenuation varied depending on the exact event, however reductions of
over 50 percent were not uncommon. Also worth noting is that near the 0.35 mile mark on
Figure 2-4-d (lower-right), the CC>2 emissions are near zero, suggesting that the vehicle is
maintaining a speed of approximately 15 MPH solely on electric power.
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Figure 2-4 Hybrid and Conventional Bus CO2 Emission Rates (g/s)
0.4
0.3
Distance (miles)
d
Other observations through this testing suggest significant complexity in the
calibration of the hybrid powertrain, presumably with the intent of reducing fuel consumption.
One example is the set of engine speed-torque points over a give route (see Figure 2-5). The
calibration of the hybrid powertrain (red) shows distinct patterns for where the engine
operates. First, the engine is less frequently loaded at, or near idle speed. Second, the engine
frequently operates at 1200 RPM, which is the lowest speed at which peak torque is available.
Third, when more power is required (beyond 100 percent torque at 1200 RPM), the engine
tends to operate along the maximum torque curve as RPM is increased. Keeping engine
speed as low as possible reduces frictional losses, thus increasing efficiency. In contrast, the
speed-torque points of the conventional bus show a much more random distribution and
propensity for operating at lower engine loads.
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Figure 2-5 Hybrid and Conventional Bus Operating Map Comparison
120
100
80
T3
ro
o
_i
CD
C
'cn
500
1000 1500 2000
Engine Speed (RPM)
2500
In summary, the hybrid powertrain has demonstrated significant opportunity for
reduction of fuel consumption and CO2 emissions in transit bus applications. Testing over
typical bus routes showed up to a 37 percent reduction in both fuel consumption and CO2
emissions. A summary of these finding is presented in Table 2-30. These reductions can be
attributed to three features of the hybrid powertrain. First, electric launch assist facilitated
through regenerative braking. Second, calibration of the engine to operate in the most efficient
regions of the speed-torque map. Third, electric-only drive at lower speeds was witnessed
occasionally.
Table 2-30 Hybrid Powertrain Benefit
Route 1
Route 2
MPG
C02 (g/mile)
CO2 (g/bhp-hr)
MPG
CO2 (g/mile)
CO2 (g/bhp-hr)
Conventional
Avg
5.15
1995
624
5.52
1859
602
CoV
8.2%
8.0%
3.7%
8.0%
7.9%
4.0%
Hybrid
Avg
7.04
1442
396
6.95
1467
410
CoV
5.5%
5.5%
5.3%
5.3%
5.5%
1.7%
Benefit
mpg or
g/mile
1.89
553
228
1.43
392
192
percent
37%
28%
37%
26%
21%
32%
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2.6.2.4 Transmission and Driveline
This technology is not expected to change as a result of the proposed standards.
2.7 Air Conditioning
Air conditioning (A/C) systems contribute to GHG emissions in two ways - direct
emissions through refrigerant leakage and indirect exhaust emissions due to the extra load on
the vehicle's engine to provide power to the air conditioning system. Hydrofluorocarbon
(HFC) refrigerants, which are powerful GHG pollutants, can leak from the A/C system. This
includes the direct leakage of refrigerant as well as the subsequent leakage associate with
maintenance and servicing, and with disposal at the end of the vehicle's life. No other vehicle
system has associated GHG leakage.79 The current refrigerant - R134a, has a high global
warming potential (GWP) of 1430.80 Due to the high GWP of this HFC, a small leakage of
the refrigerant has a much greater global warming impact than a similar amount of emissions
of CC>2 or other mobile source GHGs.
Heavy-duty air conditioning systems today are similar to those used in light-duty
applications. However, differences may exist in terms of cooling capacity (such as sleeper
cabs have larger cabin volumes than day cabs), system layout (such as the number of
evaporators), and the durability requirements due to longer truck life. However, the
component technologies and costs to reduce direct HFC emissions are similar between the
two types of vehicles.
The quantity of indirect GHG emissions from A/C use in heavy-duty trucks relative to
the CC>2 emissions from driving the vehicle and moving freight is very small. Therefore, a
credit approach for improved A/C system efficiency is not appropriate for this segment of
vehicles because the value of the credit is too small to provide sufficient incentive to utilize
feasible and cost-effective air conditioning leakage improvements. For the same reason,
including air conditioning leakage improvements within the main standard would in many
instances result in lost control opportunities. Therefore, EPA is proposing that truck
manufacturers be required to meet a low leakage requirement for all air conditioning systems
installed in 2014 model year and later trucks, with one exception. The agencies are not
proposing leakage standards for Class 2b-8 Vocational Vehicles at this time due to the
complexity in the build process and the potential for different entities besides the chassis
manufacturer to be involved in the air conditioning system production and installation, with
consequent difficulties in developing a regulatory system.
2.7.1 Refrigerant Leakage
Based on measurements from 300 European light-duty vehicles (collected in 2002 and
2003), Schwarz and Harnisch estimate that the average HFC direct leakage rate from modern
A/C systems was estimated to be 53 g/yr.81 This corresponds to a leakage rate of 6.9 percent
per year. This was estimated by extracting the refrigerant from recruited vehicles and
comparing the amount extracted to the amount originally filled (as per the vehicle
specifications). The fleet and size of vehicles differs from Europe and the United States,
therefore it is conceivable that vehicles in the United States could have a different leakage
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rate. The authors measured the average charge of refrigerant at initial fill to be about 747
grams (it is somewhat higher in the U.S. at 770g), and that the smaller cars (684 gram charge)
emitted less than the higher charge vehicles (883 gram charge). Moreover, due to the climate
differences, the A/C usage patterns also vary between the two continents, which may
influence leakage rates.
Vincent et al., from the California Air Resources Board estimated the in-use
oa
refrigerant leakage rate to be 80 g/yr. This is based on consumption of refrigerant in
commercial fleets, surveys of vehicle owners and technicians. The study assumed an average
A/C charge size of 950 grams and a recharge rate of 1 in 16 years (lifetime). The recharges
occurred when the system was 52 percent empty and the fraction recovered at end-of-life was
8.5 percent.
Since the A/C systems are similar in design and operation between light- and heavy-
duty vehicles, and emissions due to direct refrigerant leakage are significant in all vehicle
types, EPA is proposing a leakage standard which is a "percent refrigerant leakage per year"
to assure that high-quality, low-leakage components are used in each air conditioning system
design. The agency believes that a single "gram of refrigerant leakage per year" would not
fairly address the variety of air conditioning system designs and layouts found in the heavy-
duty truck sector. EPA is proposing a standard of 1.50 percent leakage per year for Heavy-
Duty Pickup Trucks and Vans and Class 7/8 Tractors. The proposed standard was derived
from the vehicles with the largest system refrigerant capacity based on the Minnesota GHG
Reporting database.83 As shown in Figure 2-6, the average percent leakage per year of the
2010 model year vehicles in the upper quartile in terms of refrigerant capacity was 1.60
percent (for reference, in the 2010 Light-Duty GHG rule, the average was estimated to be 2.7
percent, based on a leakage rate of 20.7 g/yr and a system capacity of 770 g).
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0 1200
|
D"
OJ
LL.
Median = 1.44 %/yr
A verage = 1. SO %/yr
1
-Annual Percentage Loss = Yearly Leak Rate/ Refriger
- 53 vehic es in data set (2010 model year only)
-System refrigerant capacity ranges from 810 gfChev
to 1531 g (Ford E-Series w/dua evaporators)
-Yearly % leak rate ranges from 0.78%/yr (Chevrolet E
2.77%/yr (Toyota Land Cruiser w/dual evaporator an
ant Capacity
xpress)to
d cool box)
I
I
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 2.10 2.20 2.30 2.40 2.50 2.60 2.70 2.80 2.90 3.00
Annual Percentage Refrigerant Loss (%/yr)
Figure 2-6 Distribution of Percentage Refrigerant Loss Per Year - Vehicles in Upper Quartile of A/C
System Refrigerant Capacity (from 2010 Minnesota Reporting Data).
By requiring that all heavy-duty trucks achieve the proposed leakage level of 1.50
percent per year, roughly half of the vehicles in the 2010 data sample would need to reduce
their leakage rates, and an emissions reduction roughly comparable to that necessary to
generate direct emission credits under the light-duty vehicle program would result. See 75 FR
at 25426-247. We believe that a yearly system leakage approach will assure that high-quality,
low-leakage, components are used in each A/C system design, and we expect that
manufacturers will reduce A/C leakage emissions by utilizing improved, leak-tight
components. Some of the improved components available to manufacturers are low-
permeation flexible hoses, multiple o-ring or seal washer connections, and multiple-lip
compressor shaft seals. The availability of low leakage components is being driven by the air
conditioning credit program in the light-duty GHG rule (which applies to 2012 model year
and later vehicles). EPA believes that reducing A/C system leakage is both highly cost-
effective and technologically feasible. The cooperative industry and government Improved
Mobile Air Conditioning (EVIAC) program has demonstrated that new-vehicle leakage
emissions can be reduced by 50 percent by reducing the number and improving the quality of
QA
the components, fittings, seals, and hoses of the A/C system. All of these technologies are
already in commercial use and exist on some of today's systems.
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EPA proposes that manufacturers demonstrate improvements in their A/C system
designs and components through a design-based method. The proposed method for
calculating A/C Leakage is based closely on an industry-consensus leakage scoring method,
described below. This leakage scoring method is correlated to experimentally-measured
leakage rates from a number of vehicles using the different available A/C components. Under
the proposed approach, manufacturers would choose from a menu of A/C equipment and
components used in their vehicles in order to establish leakage scores, which would
characterize their A/C system leakage performance and calculate the percent leakage per year
as this score divided by the system refrigerant capacity.
Consistent with the Light-Duty Vehicle Greenhouse Gas Emissions rulemaking, EPA
is proposing that a manufacturer would compare the components of its A/C system with a set
of leakage-reduction technologies and actions that is based closely on that being developed
through EVIAC and the Society of Automotive Engineers (as SAE Surface Vehicle Standard
J2727, August 2008 version). See generally 75 FR at 25426. The SAE J2727 approach was
developed from laboratory testing of a variety of A/C related components, and EPA believes
that the J2727 leakage scoring system generally represents a reasonable correlation with
average real-world leakage in new vehicles. Like the EVIAC approach, our proposed approach
would associate each component with a specific leakage rate in grams per year identical to the
values in J2727 and then sum together the component leakage values to develop the total A/C
system leakage. However, in the heavy-duty truck program, the total A/C leakage score is
then divided the value by the total refrigerant system capacity to develop a percent leakage
per year value.
2.7.2 System Efficiency
The agencies can also develop a program that includes efficiency improvements.
CO2-equivalent emissions are also associated with air conditioner efficiency, since air
conditioners create load on the engine. See 74 FR at 49529. However, EPA is not proposing
to set air conditioning efficiency standards for heavy-duty trucks, as the CC>2 emissions due to
air conditioning systems in heavy-duty trucks are minimal (compared to their overall
emissions of CC>2). For example, EPA conducted modeling of a Class 8 sleeper cab using
GEM to evaluate the impact of air conditioning and found that it leads to approximately 1
gram of CC>2/ton- mile. Therefore, a projected 24 percent improvement of the air
conditioning system (the level projected in the light-duty GHG rulemaking), would only
reduce CO2 emissions by less than 0.3 g CC^/ton-mile, or approximately 0.3 percent of the
baseline Class 8 sleeper cab CC>2 emissions.
2.8 Trailers and GHG Emission Reduction Opportunities
Trailers for use with HD tractors are an important aspect of the GHG emission
performance of combination tractors and are estimated to be responsible for 11 to 12 percent
of fuel consumed by Class 8 combination tractors. Optimizing the tractor and trailer as a
system allows designers to take full advantage of the GHG emission reduction opportunities
and, in some cases (e.g., aerodynamic drag reduction), the performance of emission reduction
approach is dependent upon the tractor and trailer working in concert. For example, when
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designing a tractor's roofline it is important to understand the type and physical characteristics
of the trailer for which it is intended for use. If the roofline of the tractor and trailer are
mismatched, it can result in a large, post-tractor wake (i.e., the tractors roofline is taller than
that of the trailer) or present a large, drag inducing surface (i.e., the trailer front is taller than
the top of the tractor). Even though trailers are an integral part of a combination tractor's
ultimate GHG emissions and fuel consumption, trailer design has remained relatively
unchanged when compared to the progress made in tractors. The impacts of incorporating
improved GHG emission and fuel saving performance into trailers can have long lasting
impacts since trailers are often kept in service for longer periods than tractors.
2.8.1 Current Trailer Fleet
There are approximately 5.6 million HD trailers on the roads today86. In general, it is
common to have roughly 3 trailers for every tractor to facilitate efficiency in loading and
unloading operations. Serving a wide range of needs, this trailer fleet is necessarily
comprised of a wide range of trailer types including box van (including refrigerated units),
shipping container (e.g., 20 and 40 foot ocean-going container) chassis, flat bed (including
drop deck units), dump, tanker, and specialty (e.g., grain, livestock, auto-carriers). Types of
trailers can be further subdivided by their length and height. The vast majority of HD trailers
on the road are box van trailers that are 53 feet long. Table 2-31 presents the current market
share of major types of trailers.87
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Table 2-31: Composition of Current Heavy-Duty Trailer Fleet
TRAILER TYPE
Box, van (53')
Box, van (40 - 52')
Box, van (24 - 39')
Box, van (refrigerated)
Container chassis
Dump
Flatbed
Flatbed (drop deck)
Grain
Tagalong
Tagalong (enclosed)
Other
MARKET SHARE1
(PERCENT)
45
6
9
5
7
3
8
2
2
4
2
9
Diversity in the trailer fleet is not limited to the types of trailers on the road but also
extends to the owners and operators of trailers. Trailers are owned and operated by individual
fleets, logistics companies that move goods for others, and government entities.
While approximately 10 companies manufacture approximately 80 percent of the
trailers sold, the entire trailer market includes a large number of trailer producers.88 Only 14
manufacturers have an annual sales volume of greater than 3,000 trailers with many
specializing in a type of trailer (e.g., grain, dump, tanker).
2.8.2 Trailer Technologies to Reduce GHG Emissions
Technologies for use on trailers that reduce GHG emissions and fuel consumption are
commercially available. These include aerodynamic devices, low rolling resistance tires, and
weight reduction. Trailer systems that allow a tractor to move more goods such as double
trailer configurations (e.g., Rocky Mountain Doubles with 28 or 48 foot trailers) can also be
considered as trailer strategies to reduce GHG emissions. Of these technologies, trailer
aerodynamics and low rolling resistance tires have gained wide acceptance and are discussed
in detail below.
2.8.2.1 Trailer Aerodynamics
Trailer aerodynamic technologies have focused on the box, van trailers - the largest
segment of the trailer fleet. This focus on box, van trailers may also be partially attributed to
the complexity of the shape of the non-box, van trailers which, in many cases, transport cargo
that is in the windstream (e.g., flatbeds that carry heavy equipment, car carriers, and loggers).
For non-box, van trailers you could have a different aerodynamic shape with every load.
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While some technologies exist to address aerodynamic drag for non-box, van trailers, it has
been either experimental or not widely commercially available.
Current trailer aerodynamic technologies for box, van trailers are estimated to provide
approximately 7 percent GHG emission reductions when used as a package. For box, van
trailers, trailer aerodynamic technologies have addressed drag at the front of the trailer (i.e.,
vortex traps, leading edge fairings), underneath the trailer (i.e., side skirts, wheel fairings) and
the trailer rear (i.e., afterbodies). These technologies are commercially available and have
seen moderate adoption rates. Table 2-32 shows technologies that have generally been
accepted for use on box, van trailers. In general, the performance of these technologies is
dependent upon the smooth transition of airflow from the tractor to the trailer. True for both
tractor and trailer aerodynamic drag reduction, the overall shape can be optimized to
minimize aerodynamic drag and, in fact, the trailer body must have at least a moderately
aerodynamic shape (and its relatively smooth flow) to benefit from add-on aerodynamic
components.
Table 2-32: Trailer Technologies to Address Aerodynamic Drag
LOCATION ON
TRAILER
Front
Front
Rear
Undercarriage
Undercarriage
Accessories
General
TECHNOLOGY TYPE
Vortex trap
Front fairings
Afterbody (boat tail and
rear fairings)
Side skirts
Underbelly treatment
General
Advanced, passive air
management
DESIGNED EFFECT
Reduce drag induced by cross-flow through
gap between tractor and trailer
Smoothly transition air to flow from tractor
to the trailer
Reduce pressure drag induced by the trailer
wake
Manage flow of air underneath tractor to
reduce eddies and wake
Manage flow of air underneath tractor to
reduce eddies and wake
Reducing surface area perpendicular to
travel and minimizing complex shapes that
may induce drag
Manage airflow through passive
aerodynamic shapes or devices that keep
flow attached to the vehicle (tractor and
trailer)
Table 2-33 Trailer Technologies Incremental Costs
TECHNOLOGY
Trailer Side Skirts
Gap Fairing
Trailer Aerocone
Boat Tails
Air Tabs
COST ESTIMATE
$1300-1600
$850
$1000
$1960
$180
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2.8.2.2 Tires - Single Wide and Low Rolling Resistance
Beginning in 2007, EPA began designating certain new dry freight box van trailers for
on the road use of 53 feet or greater length Certified SmartWay Trailers. Older or pre-owned
trailers could also be certified if properly retrofitted. In order for a trailer to be designated as
Certified SmartWay, the trailer must be equipped with verified low rolling resistance trailer
tires (either dual or single-wide), among other things.
The RRC baseline for today's fleet is 6.5 kg/metric ton for the trailer tire, based on
sales weighting of the top three manufacturers based on market share. This value is based on
new trailer tires, since rolling resistance decreases as the tread wears. To achieve the intended
emissions benefit, SmartWay established the maximum allowable RRC for the trailer tire 15
percent below the baseline or 5.5 kg/metric ton.
Research indicates the contribution to overall vehicle fuel efficiency by tires is
approximately equal to the proportion of the vehicle weight on them. On a fully loaded
typical Class 8 long-haul tractor and trailer, 42.5 percent of the total tire energy loss attributed
to rolling resistance is from the trailer tires.
The Center for Transportation Research at Argonne National Laboratory analyzed
technology options to support energy use projections. EPA agrees with their assumed
incremental cost of low rolling resistance tires of $15 - $20 per tire. With 8 tires replaced on
a trailer, the incremental cost would be between $120 and $160. Often the steer tire is
retreaded and placed on the trailer axle. There is a cost savings associated with retread tires.
A new retread costs between $150 and $200, compared to a new tire which costs typically
around $400. This represents a savings of $1,200 to $1,600 per trailer.
Single wide tires are also used on trailers. The Center for Transportation Research
estimated incremental capital cost of single wide tires is $30 - $40 per tire. With 4 single
wide tires replacing 8 dual tires on the trailer, the incremental cost would be between $120
and $160.
OQ
Based on the ICF report, EPA and NHTSA estimate the incremental retail cost for
low rolling resistance tires as $78 per tire. The agencies also estimate that the incremental
cost to replace a pair of dual tires with a single wide based tire is $216, however, the cost can
be reduced when the wheel replacement cost is considered.
2.8.2.3 Trailer Weight Reduction
Weight reduction opportunities in trailers exist in both the structural components and
in the wheels and tires. Material substitution (replacing steel with aluminum) is feasible for
components such as roof posts, bows, side posts, cross members, floor joists, and floors.
Similar material substitution is feasible for wheels. Weight reduction opportunities also exist
through the use of single wide based tires replacing two dual tires.
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The agencies' assessment of the ICF report indicates that the expected incremental
retail prices of the lightweighted components are as included in Table 2-34 Trailer
Lightweighting Incremental Costs.
Table 2-34 Trailer Lightweighting Incremental Costs
COMPONENT
Roof Posts/Bows
Side Posts
Cross Members/Floor Joists
Floor
Wheels
COST
$120
$525
$400
$1,500
$1,500
2.8.2.4 Opportunities in Refrigerated Trailers
Refrigeration units are used in van trailers to transport temperature sensitive products.
A traditional trailer refrigeration unit (TRU) is powered by a nonroad diesel engine. There
are GHG reduction opportunities in refrigerated trailers through the use of electrical trailer
refrigeration units and highly reflective trailer coatings.
Highly reflective materials, such as reflective paints or translucent white fiberglass
roofs, can reflect the solar radiation and decrease the cooling demands on the trailer's
refrigeration unit. A reflective composite roof can cost approximately $800, the addition of
reflective tape to a trailer roof would cost approximately $450.
Hybrid TRUs utilize a diesel engine which drives a generator which in turn powers the
compressor and fans. The cost of this unit is approximately $4,000.
All-electric TRUs, needing no diesel engine to power the unit, are being tested in U.S.
refrigerated fleets. There is no market price for these units at this time.
2.9 Other Fuel Consumption and GHG Reducing Strategies
There are several other types of strategies available to reduce fuel consumption and
GHG emissions from trucks. EPA and NHTSA identify several of these technologies and
strategies below, but acknowledge that they are outside the proposed regulatory framework
currently identified.
2.9.1 Auxiliaries
The accessories on a truck engine, including the alternator, coolant and oil pumps are
traditionally mechanically gear or belt driven by the base engine. In general, the effect of
accessory power consumption in trucks is much less than in cars but the mechanical
auxiliaries operate whenever base engines are running, which can waste energy when the
auxiliaries are not needed. The replacement of mechanical auxiliaries by electrically driven
systems can decouple mechanical loads from the base engine and reduce energy use. Since
the average engine loads from mechanical auxiliaries are higher than those from a small
generator that supplies electricity to electric auxiliaries, base engine fuel can be reduced. A
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reduction in CC>2 emissions and fuel consumption can be realized by driving them electrically
and only when needed ("on-demand"). The heavy and medium trucks have several auxiliary
systems:
• Air compressor,
• Hydraulic pumps,
• Coolant pump,
• Engine oil and fuel pumps,
• Fans, and
• Air conditioning compressor.
The systems listed above, although not inclusive, can be optimized by various
methods reducing fuel consumption and GHG emissions;
• Electric power steering (EPS) - is an electrically-assisted steering system that has
advantages over traditional hydraulic power steering because it replaces a
continuously operated hydraulic pump, thereby reducing parasitic losses from the
accessory drive.
• Electric water pumps and electric fans - can provide better control of engine cooling.
For example, coolant flow from an electric water pump can be reduced and the
radiator fan can be shut off during engine warm-up or cold ambient temperature
conditions which will reduce warm-up time, reduce warm-up fuel enrichment, and
reduce parasitic losses. Indirect benefit may be obtained by reducing the flow from the
water pump electrically during the engine warm-up period, allowing the engine to heat
more rapidly and thereby reducing the fuel enrichment needed during cold starting of
the engine.
• High efficiency alternators - provide greater electrical power and efficiency at road
speed or at idle than conventional original equipment replacement alternators that
typically operate at 55 percent efficiency.
• If electric power is not available - there are still some technologies that can be applied
to reduce the parasitic power consumption of accessories. Increased component
efficiency is one approach, and clutches can be used to disengage the alternator and air
compressor when they are not required. Many MD/HD engines incorporate clutched
cooling fans which can be shut off during engine warm-up thereby not requiring
electric cooling fans. Air compressors that are rotating but not creating pressure
absorb about half the power of a pumping compressor, and compressors normally only
pump a small percentage of the time in long-haul trucks.
Several studies have documented the GHG reductions from electrification and/or
optimization of truck auxiliaries. One study, based on a full-scaled test of a prototype truck
that used a small generator to produce electricity, full electrification of auxiliaries reduces fuel
use by 2 percent including extended idle and estimated potential reductions in modal GHG
emissions are 1.4 percent. Another study recently completed by Ricardo discussed the
advantages of electrification of engine accessories along with the potential to increase fuel
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Regulatory Impact Analysis
on
economy citing examples such as variable flow water pumps and oil pumps . Potential gains
may be realized in the range of 1 to 3 percent but are highly dependent on truck type, size and
duty cycle. In a NESCAFE study, the accessory power demand of a baseline truck was
modeled as a steady state power draw of 5 kW, and 3 kW for more electrical accessories in
individual vehicle configurations that included electric turbo compounding. The 2 kW savings
versus average engine power of 100 to 200kW over a drive cycle nets roughly 1 to 2 percent
savings compared to a baseline vehicle.
Accurate data providing power consumption values for each discrete accessory over a
range of operating conditions was not available due to the variation of the truck fleet. Based
on research and industry feedback, a simplified assumption for modeling was made that the
average power demand for mechanically driven accessories is 5 kW, and the average power
demand for electrically driven accessories is 3 kW. This provides a 2 kW advantage for the
electrically driven accessories over the entire drive cycle represent and is estimated to provide
a 1.5 percent improvement in efficiency and reduction in CO2 emissions. As a comparison,
the average load on a car engine over a drive cycle may be in the 10 to 20 kW range. At this
level, a 2 kW reduction in accessory loads of a passenger vehicle makes a significant
difference (approximately 10 percent). Given the higher loads experienced by truck engines,
accessory demand is a much smaller share of overall fuel consumption. Accessory power
demand determined by discrete components will be not be included in the model at this time
and a power draw of 5 kW for standard accessories and 3 kW for electrical accessories will be
used. There is opportunity for additional research to improve upon this simple modeling
approach by using actual measured data to improve the modeling assumptions.
2.9.2 Driver training
Driver training that targets fuel efficiency can help drivers recognize and change
driving habits that waste fuel and increase harmful emissions. Even highly experienced truck
drivers can boost their skills and enhance driving performance through driver training
programs.91
Driving habits that commonly waste fuel are high speed driving, driving at
unnecessarily high rpm, excessive idling, improper shifting, too-rapid acceleration,
unnecessarily frequent stops and starts, and poor route planning. Well-trained drivers can
reduce fuel consumption by applying simple techniques to address vehicle and engine speed,
shifting patterns, acceleration and braking habits, idling, and use of accessories.92 Some
techniques include starting out in a gear that does not require using the throttle when releasing
the clutch, progressive shifting (upshifting at the lowest possible rpm), anticipating traffic
flow to reduce starts and stops, use of block shifting where possible (e.g., shifting from 2nd to
5th gear), using cruise control as appropriate, and coasting down or using the engine brake to
slow the vehicle, instead of gearing down or using the brake pedal.
As discussed elsewhere in this chapter, idling can be eliminated by the use of auxiliary
power units or other idle reduction solutions that provide power or heating and cooling to the
cab at a much lower rate of energy consumption.
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
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Better route planning that reduces unnecessary mileage and the frequency of empty
backhauls, and takes into account factors like daily congestion patterns is another facet of a
comprehensive driver training program. Such planning can be assisted through the use of
logistics companies, which specialize in such efficiencies.
In its report, Technologies and Approaches to Reducing the Fuel Consumption of
Medium and Heavy-Duty Vehicles, the National Research Council cited studies that found, on
average, a five percent improvement in vehicle fuel efficiency due to driver training.93 EPA's
SmartWay Transport Partnership has documented the success of dozens of trucking
companies' use of driver training programs. One company reported saving an average of 42
gallons per student, or 335,000 gallons of fuel per year; and, saving 837,000 gallons of fuel in
the four years it has had its training program in place.94 Trucking fleets can provide
additional motivation to reward drivers for improved performance with incentive programs,
which may be monetary or provide other forms of benefits and recognition. Sometimes
negative measures are employed to urge compliance with company expectations, up to and
including termination of employment. Successful programs are those that perform ongoing
reviews of driver techniques, and provide assistance to improve and/or retrain drivers.
While EPA and NHTSA recognize the potential opportunity to reduce fuel
consumption and greenhouse gas emissions by encouraging fuel-efficient driver habits,
mandating driver training for all of the nation's truck drivers is beyond the scope of this
proposed regulation. However, in developing this proposal, the agencies did consider
technologies that can provide some of the benefits typically addressed through driver training.
Examples include automatic engine shutdown to reduce idling, automated or automated
manual transmissions to optimize shifting, and speed limiters to reduce high speed operation.
EPA will continue to promote fuel-efficient driving through its SmartWay program. In
addition to providing fact sheets on fuel efficient driving,95 SmartWay is collaborating with
Natural Resources Canada's FleetSmart program to develop a web-enabled "fuel efficient
driver" training course for commercial truck drivers. Once the course is developed, it will
complement the agencies regulatory program by making fuel efficient driver training
strategies available to any commercial truck driver.
2.9.3 Automatic Tire inflation and Tire Pressure Monitoring System
Underinflation of tires has the potential to reduce fuel economy by as much as two to
three percent96. Although most truck fleets understand the importance of keeping tires
properly inflated, it is likely that a substantial proportion of trucks on the road have one or
more underinflated tires. An industry survey conducted in 2002 at two truck stops found that
fewer than half of the tires checked were within five pounds of their recommended inflation
pressure. Twenty-two percent of the vehicles checked had at least one tire underinflated by at
least twenty pounds per square inch (psi), and four percent of the vehicles were running with
at least one flat tire, defined as a tire underinflated by fifty psi or more. The survey also found
mismatches in tire pressure exceeding five percent for dual tires on axle ends.97
Proper tire inflation pressure can be maintained with a rigorous tire inspection and
maintenance program or with the use of tire pressure and inflation systems. These systems
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Regulatory Impact Analysis
monitor tire pressure; some also automatically keep tires inflated to a specific level.
However, while the agencies recognize that such devices could have a beneficial effect on
fuel economy, their use is not included in the regulatory framework. Notwithstanding the
cited survey, the level of underinflation of tires in the American truck fleet is not known,98
which means that neither a baseline value nor an estimate of the fuel savings from the use of
automatic tire inflation systems can be quantified with certainty. Through its SmartWay
program, however, EPA does provide information on proper tire inflation pressure and on tire
inflation and tire inflation pressure monitoring systems."
2.9.4 Engine Features
Previous sections 2.3.2.2 through 2.3.2.8 describe the technologies that can be tested
in an engine test cell for certification purpose and could be potentially implemented in
production before the time frame of 2017. Some other technologies that cannot be easily
tested in an engine test cell, but can improve engine fuel economy, should be worthwhile
mentioning. Examples include these technologies, such as driver rewards, load based speed
control, gear down protection, and fan control offered by Cummins's PowerSpec.
The driver reward developed by Cummins monitors and averages the driver trip fuel
economy and trip idle percent time at regular intervals, seeking to modify driver behavior by
offering incentives to use less fuel. Desirable driving habits, such as low percentage of idle
time, and high MPG, are rewarded with higher limits on the road speed governor, cruise
control or both. The load based speed control or other similar programs are designed to
improve fuel economy, lower vehicle noise, and improve driver satisfaction by managing
engine speed (rpm) based on real time operating conditions. During high power requirements,
this type of technology enhances engine performance by providing the driver with an
extended operating range. In addition to the fuel economy benefits from operating the engine
at lower speeds, vehicle noise is lowered.
Gear down protection offered by Cummins is to promote increased fuel economy by
encouraging the vehicle driver to operate as much as effectively possible in top gear where
fuel consumption is lower. This can be done by limiting vehicle speed in lower gears.
Maximizing time in top gear means the engine runs in a lower rpm range, where fuel
economy is best with improved durability and without compromising performance. Difference
between top gear and one gear down can be as much as 16 percent in fuel economy. More
detailed descriptions of many technologies including those mentioned here can be viewed at
Cummins's website of http://www.powerspec.cummins.com/site/home/index.html.
Although these technologies mentioned in this section are not able to be tested in an
engine test cell environment, thus being unable to be directly used for benefits of certification
purpose, the agency encourages manufacturers to continue improving the current and
developing new technologies, thereby reducing green house gases in a broader way.
2.9.5 Logistics
Logistics encompasses a number of interrelated, mostly operational factors that affect
how efficiently the overall freight transport system works. These factors include choice of
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
Effectiveness
mode, carrier and equipment; packaging type and amount; delivery time; points of origin and
destination; route choice, including locations of ports and distribution hubs; and transportation
tracking systems. These factors are controlled by the organizations that ship and receive
goods. Due to the specialized nature of logistics management, organizations increasingly rely
upon internal or outsourced business units to handle this function; many transportation
providers offer logistics management services to their freight customers.
Because optimizing logistics is specific to each individual freight move, neither EPA
nor NHTSA believed it is feasible to manage logistics through this proposed regulation.
However, implementing certain system-wide logistics enhancements on a national level could
provide benefits. As described in the National Research Council's recent report,100 a broader
national approach could include enhanced telematics and intelligent transportation systems;
changes to existing infrastructure to optimize modal choice; and increased truck capacity
through changes to current truck weight and size limits. While such a broad transformation of
our freight system is worthwhile to consider, implementing such system-wide changes falls
outside the scope of this proposed regulation. As the National Research Council noted,101 due
to its complex nature, logistics management is not readily or effectively addressed through
any single approach or regulation; a number of complementary measures and alternatives are
needed. Such measures can include initiatives that enable companies to better understand,
measure and track the benefits of logistics optimization from an environmental and economic
standpoint. The SmartWay program provides uniform tools and methodologies that
companies can use to assess and optimize transportation supply chains, and can complement
any future regulatory and nonregulatory approaches.
2.9.6 Longer Combination Vehicles, Weight Increase
Longer combination vehicles (LCVs) are tractor-trailer combinations that tow more
than one trailer, where at least one of the trailers exceeds the "pup" size (typically 24-28 feet).
Because LCVs are capable of hauling more freight than a typical tractor-trailer combination,
using LCVs reduces the number of truck trips needed to carry the same amount of freight. On
a fleetwide basis, this saves fuel, reduces greenhouse gas emissions, and reduces per-fleet
shipping costs. A typical non-LCV may tow a single trailer up to 53 feet in length, or tow two
pup trailers, or even be a straight truck with a pup trailer connected via a draw bar. In
contrast, the typical LCV may consist of a tractor towing two trailers of 45-48 feet, and
occasionally 53 feet in length (a "turnpike double"), or one of that size and one pup (a "Rocky
Mountain double"), or may tow three pups (a "triple").
Trucks consisting of a two-axle tractor combined with two one-axle trailers up to 28.5
feet are permitted on all highways in the U.S. National Network, which consists of the
interstate highway system and certain other roads. Individual states may permit longer LCVs
to operate on roads that are not part of the National Network. They are allowed in 16 western
states, but only on turnpikes in the five states east of the Mississippi that allow them; no new
states were granted permitting authority for LCVs after 1991.102 Regulations vary among
states; some allow LCVs with more than three trailers, but only by permit. Longer length
turnpike doubles are typically restricted to tolled turnpikes. Such restrictions are based on
considerations of the difficulty of operation and on expected weather conditions. Other
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Regulatory Impact Analysis
regulations on the types of LCVs allowed are seen in other countries; in Australia, "road
trains" of up to four trailers, usually with three axles per trailer, are permitted.
Some proponents of liberalized size and weight regulations project substantial
benefits, estimating that highway freight productivity could be doubled and costs reduced.
Despite the potential benefits of LCVs, as the National Research Council noted in its recent
report, there are considerations that may make LCVs less cost effective and less safe. For
example, if infrastructure (e.g., bridges with sufficient capacity; roadways with adequate lane
width and curb radii for turning to accommodate an LCV safely) are not available without
traveling far from a more efficient route, or if there is insufficient opportunity for the LCV to
make the most of the available volume in multiple trailers, then LCVs would not be cost
effective.
The increased vehicular weight of LCVs is both a safety issue and a road maintenance
issue (see discussion below on increasing vehicle weight and legal load limits). The
additional weight of extra trailers increases braking and stopping distance, and adds difficulty
in maintaining speed in grade situations.
With additional regard to safety, LCVs might have trouble with offtracking (when the
truck's front and rear wheels do not follow the same path, which can result in departing the
lane boundaries—a particular problem with longer LCVs), and could increase the challenge of
merging with and maneuvering in traffic. Lateral stability is a greater problem in LCVs, and
leads to a greater chance of rollover, particularly when the individual trailers are shorter.
Also, when a vehicle is passing a LCV on a two-lane road, the period of time spent in the
opposing lane (up to 2-3 seconds) poses another safety problem.103 Such safety
considerations impact decisions regarding restrictions on the use of LCVs, even when they
may otherwise be a cost effective freight choice.
Moves to increase commercial vehicle weight limits concern not only relaxing
limitations on the use of LCVs, but also increasing gross vehicle weight limits for single unit
trucks and conventional tractor-trailer combinations, as well as increasing axle load limits and
trailer lengths. Some analysts cite scenarios in which such relaxations result in increased
highway freight productivity, while yielding significant reductions in shipping costs,
congestion, and total vehicle miles traveled. Increasing the weight limits allows commercial
freight vehicles to carry heavier loads, reducing the number of trucks required to transport
freight, potentially resulting in overall emissions reductions.
Federal law limits gross vehicle weight for commercial vehicles operating in the
Interstate Highway System to a maximum of 80,000 Ibs. (maximum 20,000 Ibs. per single
axle, 34,000 Ibs. per tandem axle), with permits available for certain oversize or overweight
loads and exceptions allowing 400 Ibs. more for tractors with idle reduction devices.
Additional vehicle weight limitations have been set by state and local regulations. These
limitations arise from considerations of infrastructure characteristics, traffic densities,
economic activities, freight movement, mode options, and approach to transportation design.
In some cases, state limits are higher than federal limits.104 While these parameters are
changeable, federal weight limits on vehicles have not changed since 1982, and limits set by
states have been frozen since 1991.
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
Effectiveness
In response to input from the freight transportation sector and other interested
parties, the Department of Transportation, the Transportation Research Board, the General
Accounting Office, and others have conducted studies examining the impacts of proposals
related to liberalized weight limits. However, regardless of the potential benefits of such
action, the analyses predict premature degradation of infrastructure (e.g., bridges, pavement,
grades) as a consequence. Increased costs required to maintain and upgrade the highway
system would impose high burdens on already-strained public resources, raising serious
questions on the desirability of relaxing weight limits, and on whether such expenditures
provide adequate public good to justify them. Safety issues similar to those cited for LCVs
enter into this debate, as do concerns with the effect on the efficiency of automotive travel,
impacts on and net productivity of other shipping modes (particularly rail), and potential
environmental and social costs.
The National Research Council in its recent report105 recognized the complexities
and potential trade-offs involved in increasing vehicle size and weight limits. While is worthy
to discuss the potential emission and energy benefits of heavier and longer trucks, the far-
reaching policy ramifications extend far beyond the scope of this proposal.
2.9.7 Traffic Congestion Mitigation
There are a wide range of strategies to reduce traffic congestion. Many of them are
aimed at eliminating light-duty vehicle trips such as mass transit improvements, commute trip
reduction programs, ridesharing programs, implementation of high occupancy vehicle lanes,
parking pricing, and parking management programs. While focused on reducing light-duty
vehicle trips, these types of strategies would allow heavy- and medium-duty vehicles to travel
on less congested roads and thereby use less fuel and emit less CC>2.
A second group of strategies would directly impact CC>2 emissions and fuel
consumption from all types of vehicles. One example of these strategies is road pricing
including increasing the price of driving on certain roads or in certain areas during the most
congested periods of the day. A second example is reducing the speed limits on roads and
implementing measures to ensure that drivers obey the lower speed limits such as increased
enforcement or adding design features that discourage excessive speeds.
Some strategies would be designed to effect trips made by heavy- and medium-duty
trucks. These would include programs to shift deliveries in congested areas to off-peak hours.
Another example is to modify land use so that common destinations are closer together, which
reduces the amount of travel required for goods distribution.
These types of congestion relief strategies have been implemented in a number of
areas around the country. They are typically implemented either by state or local
governments or in some cases strategies to reduce commuting trips and scheduling off-peak
deliveries have been implemented by private companies or groups of companies.
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Regulatory Impact Analysis
2.10 Summary of Technology Costs Used in this Analysis
Table 2-35 shows the technology costs used throughout this analysis for heavy-duty
engines, vocational vehicles and combination tractors for the years 2014-2020. Table 2-36
shows the technology costs used throughout this analysis for Class 2b and 3 diesel and
gasoline trucks for the years 2014-2020. These tables reflect the impact of learning effects on
estimated technology costs. Refer to Table 2-1 for details on the ICMs applied to each
technology and Table 2-2 for the type of learning applied to each technology. The costs
shown in the tables do not include the penetration rates so do not always reflect the
technology's contribution to the resultant package costs. One final note of clarification is that
the terms "MHDDcomb" and "HHDDcomb" in the "Class" column refer specifically to
engines placed in combination tractors (Class 7 and 8 day cabs and sleeper cabs).
-------
Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and Effectiveness
Table 2-35 Technology Effectiveness and Costs, Inclusive of Markups, by Year for Heavy-duty DieselA and Gasoline Engines, Vocational Vehicles, and
Combination Tractors (2008$)
Technology
Aftertreatment
improvements
Turbo efficiency
improvements
Piston improvements
Optimized water pump
Optimized oil pump
Optimized fuel pump
Valve train friction
reductions
Optimized fuel rail
Optimized fuel injector
EGR cooler improvements
Cylinder head
improvements
2014 MY LHDD Engine
Package
Applied
to
Engine
Engine
Enaine
Enaine
Enaine
Enaine
Enaine
Enaine
Enaine
Enaine
Engine
Engine
Truck type
Class
LHDD
LHDD
LHDD
LHDD
LHDD
LHDD
LHDD
LHDD
LHDD
LHDD
LHDD
LHDD
CO2eq
Effectiveness
1-4%
1-2%
0.5-2%
2-7%
5%
2014
$111
$17
$3
$87
$4
$4
$104
$11
$14
$3
$10
$369
2015
$108
$17
$o
3
$84
$4
$4
$101
$11
$13
$3
$10
$358
2016
$104
$16
$2
$82
$4
$4
$98
$11
$13
$3
$10
$348
2017
$101
$16
$2
$79
$4
$4
$95
$10
$13
$3
$9
2018
$98
$17
$2
$77
$4
$4
$92
$10
$12
$3
$9
2019
$96
$17
$2
$75
$4
$4
$90
$10
$12
$3
$9
2020
$94
$16
$2
$74
$4
$4
$88
$10
$12
$3
$9
The costs included in the table represent technology costs. The engineering costs of $6,750,000 per diesel engine manufacturer per year for a five year period
are not included in the table.
2-89
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Regulatory Impact Analysis
Technology
20 17 MY LHDD Engine
Package
Applied
to
Engine
Truck type
Class
LHDD
CO2eq
Effectiveness
9%
2014
2015
2016
2017
$337
2018
$327
2019
$321
2020
$314
Aftertreatment
Improvements
Turbo efficiency
improvements
Piston improvements
Optimized water pump
Optimized oil pump
Optimized fuel pump
Valve train friction
reductions
Optimized fuel rail
Optimized fuel injector
EGR cooler improvements
Cylinder head
improvements
2014 MY MHDD Engine
Package
2017 MY MHDD Engine
Package
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
MHDD
MHDD
MHDD
MHDD
MHDD
MHDD
MHDD
MHDD
MHDD
MHDD
MHDD
MHDD
MHDD
1-4%
1-2%
0.5-2%
2-7%
5%
9%
InR&D
$17
$3
$87
$4
$4
$78
$10
$10
$3
$6
$223
InR&D
$17
$3
$84
$4
$4
$76
$9
$10
$3
$6
$216
InR&D
$16
$2
$82
$4
$4
$73
$9
$10
$3
$6
$210
InR&D
$16
$2
$79
$4
$4
$71
$9
$9
$3
$6
$203
InR&D
$15
$2
$77
$4
$4
$69
$8
$9
$3
$5
$197
InR&D
$15
$2
$75
$4
$4
$68
$8
$9
$3
$5
$193
InR&D
$15
$2
$74
$4
$4
$66
$8
$9
$3
$5
$189
Aftertreatment
Improvements
Turbo efficiency
improvements
Piston improvements
Optimized water pump
Optimized oil pump
Optimized fuel pump
Valve train friction
reductions
Optimized fuel rail
Optimized fuel injector
EGR cooler improvements
Cylinder head
improvements
Turbo mechanical-
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
MHDDcomb
MHDDcomb
MHDDcomb
MHDDcomb
MHDDcomb
MHDDcomb
MHDDcomb
MHDDcomb
MHDDcomb
MHDDcomb
MHDDcomb
MHDDcomb
1-4%
1-2%
0.5-2%
2-7%
2.5-5%
InR&D
$17
$3
$87
$4
$4
$78
$10
$10
$3
$6
-
InR&D
$17
$3
$84
$4
$4
$76
$9
$10
$3
$6
-
InR&D
$16
$2
$82
$4
$4
$73
$9
$10
$3
$6
-
InR&D
$16
$2
$79
$4
$4
$71
$9
$9
$3
$6
$823
InR&D
$15
$2
$77
$4
$4
$69
$8
$9
$3
$5
$798
InR&D
$15
$2
$75
$4
$4
$68
$8
$9
$3
$5
$782
InR&D
$15
$2
$74
$4
$4
$66
$8
$9
$3
$5
$767
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and Effectiveness
Technology
compounding
2014 MY MHDD Engine
Package
2017 MY MHDD Engine
Package
Applied
to
Engine
Engine
Truck type
Class
MHDDcomb
MHDDcomb
CO2eq
Effectiveness
3%
5%
2014
$223
2015
$216
2016
$210
2017
$1,027
2018
$996
2019
$976
2020
$956
Aftertreatment
Improvements
Turbo efficiency
improvements
Piston improvements
Optimized water pump
Optimized oil pump
Optimized fuel pump
Optimized fuel rail
Optimized fuel injector
Cylinder head
improvements
EGR cooler improvements
2014 MY HHDD Engine
Package
20 17 MY HHDD Engine
Package
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
HHDD
HHDD
HHDD
HHDD
HHDD
HHDD
HHDD
HHDD
HHDD
HHDD
HHDD
HHDD
1-4%
1-2%
0.5-2%
2-7%
5%
9%
InR&D
$17
$3
$87
$4
$4
$10
$10
$6
$3
$145
InR&D
$17
$3
$84
$4
$4
$9
$10
$6
$3
$140
InR&D
$16
$2
$82
$4
$4
$9
$10
$6
$3
$136
InR&D
$16
$2
$79
$4
$4
$9
$9
$6
$3
$132
InR&D
$15
$2
$77
$4
$4
$8
$9
$5
$3
$128
InR&D
$15
$2
$75
$4
$4
$8
$9
$5
$3
$126
InR&D
$15
$2
$74
$4
$4
$8
$9
$5
$3
$123
Aftertreatment
Improvements
Turbo efficiency
improvements
Piston improvements
Optimized water pump
Optimized oil pump
Optimized fuel pump
Optimized fuel rail
Optimized fuel injector
Cylinder head
improvements
EGR cooler improvements
Turbo mechanical-
compounding
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
Engine
HHDDcomb
HHDDcomb
HHDDcomb
HHDDcomb
HHDDcomb
HHDDcomb
HHDDcomb
HHDDcomb
HHDDcomb
HHDD
HHDDcomb
1-4%
1-2%
0.5-2%
2-7%
2.5-5%
InR&D
$17
$3
$87
$4
$4
$10
$10
$6
$3
-
InR&D
$17
$3
$84
$4
$4
$9
$10
$6
$3
-
InR&D
$16
$2
$82
$4
$4
$9
$10
$6
$3
-
InR&D
$16
$2
$79
$4
$4
$9
$9
$6
$3
$823
InR&D
$15
$2
$77
$4
$4
$8
$9
$5
$3
$798
InR&D
$15
$2
$75
$4
$4
$8
$9
$5
$3
$782
InR&D
$15
$2
$74
$4
$4
$8
$9
$5
$3
$767
2-91
-------
Regulatory Impact Analysis
Technology
2014 MY HHDD Engine
Package
2017 MY HHDD Engine
Package
Applied
to
Engine
Engine
Truck type
Class
HHDDcomb
HHDDcomb
CO2eq
Effectiveness
3%
5%
2014
$145
2015
$140
2016
$136
2017
$955
2018
$927
2019
$908
2020
$890
Engine friction reduction
Coupled valve timing
Stoich GDI-V8
HD Gasoline Engine
Package -20 16 MY
Engine
Engine
Engine
Engine
HDG
HDG
HDG
HDG
1-3%
1-4%
1-2%
5%
—
—
—
-
—
—
—
-
$88
$43
$372
$504
$88
$42
$361
$491
$88
$40
$350
$479
$88
$40
$343
$471
$88
$39
$336
$464
LRR steer tire 5. 7
LRR drive tire 7.0
2014MY Vehicle Package
Truck
Truck
Truck
Vocational
Vocational
Vocational
LH
LH
LH
2-3%
3%
$65
$91
$155
$65
$91
$155
$52
$72
$124
$52
$72
$124
$42
$58
$99
$40
$56
$96
$39
$55
$94
LRR steer tire 5. 7
LRR drive tire 7.0
2014MY Vehicle Package
Truck
Truck
Truck
Vocational
Vocational
Vocational
MH
MH
MH
2-3%
3%
$65
$91
$155
$65
$91
$155
$52
$72
$124
$52
$72
$124
$42
$58
$99
$40
$56
$96
$39
$55
$94
LRR steer tire 5. 7
LRR drive tire 7.0
2014MY Vehicle Package
Truck
Truck
Truck
Vocational
Vocational
Vocational
HH
HH
HH
2-3%
2%
$65
$121
$186
$65
$121
$186
$52
$97
$148
$52
$97
$148
$42
$77
$119
$40
$75
$115
$39
$73
$112
Aero-SmartWay
Aero-SmartWay Advance
LRR steer tire
LRR drive tire
Weight reduction: Single-
wide tire
Weight reduction:
Aluminum steer wheel
Weight reduction:
Aluminum single- wide
wheel
Air Conditioning Leakage
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Class7 DayCab
Class7 DayCab
Class7 DayCab
Class7 DayCab
Class7_DayCab
Class7_DayCab
Class7_DayCab
Class7 DayCab
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
1-2%
2-3%
1-3%
<1%
<1%
$1,079
$2,179
$65
$60
$322
$523
$627
$21
$1,046
$2,179
$63
$59
$312
$507
$608
$20
$1,015
$1,743
$61
$57
$303
$492
$590
$20
$985
$1,743
$59
$55
$294
$477
$572
$19
$955
$1,394
$57
$53
$285
$463
$555
$19
$936
$1,353
$56
$52
$279
$454
$544
$18
$917
$1,312
$55
$51
$274
$445
$533
$18
2-92
-------
Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and Effectiveness
Technology
20 14MY Vehicle
Package8
Applied
to
Truck
Truck type
Class7_DayCab
Class
LowRoof
CO2eq
Effectiveness
3-4%
2014
$2,593
2015
$2,529
2016
$2,379
2017
$2,318
2018
$2,189
2019
$2,142
2020
$2,097
Aero-SmartWay
Aero-SmartWay Advance
LRR steer tire
LRR drive tire
Weight reduction: Single-
wide tire
Weight reduction:
Aluminum steer wheel
Weight reduction:
Aluminum single- wide
wheel
Air Conditioning Leakage
2014MY Vehicle Package
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Class? DayCab
Class? DayCab
Class? DayCab
Class? DayCab
Class?_DayCab
Class?_DayCab
Class7_DayCab
Class? DayCab
Class? DayCab
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
2-4%
3-5%
1-3%
<1%
<1%
6-7%
$1,107
$2,207
$65
$60
$322
$523
$627
$21
$2,835
$1,074
$2,207
$63
$59
$312
$507
$608
$20
$2,763
$1,042
$1,766
$61
$57
$303
$492
$590
$20
$2,605
$1,011
$1,766
$59
$55
$294
$477
$572
$19
$2,537
$980
$1,413
$57
$53
$285
$463
$555
$19
$2,401
$961
$1,370
$56
$52
$279
$454
$544
$18
$2,350
$941
$1,329
$55
$51
$274
$445
$533
$18
$2,301
Aero-SmartWay
Aero-SmartWay Advance
LRR steer tire
LRR drive tire
Weight reduction: Single-
wide tire
Weight reduction:
Aluminum steer wheel
Weight reduction:
Aluminum single- wide
wheel
Air Conditioning Leakage
2014MY Vehicle Package
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
ClassS DayCab
Class 8 DayCab
ClassS DayCab
ClassS DayCab
Class8_DayCab
Class8_DayCab
Class8_DayCab
ClassS DayCab
Class8_DayCab
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
1-2%
2-3%
1-3%
<1%
<1%
3-4%
$1,079
$2,179
$65
$121
$644
$523
$1,254
$21
$3,275
$1,046
$2,179
$63
$117
$624
$507
$1,216
$20
$3,176
$1,015
$1,743
$61
$114
$606
$492
$1,180
$20
$3,081
$985
$1,743
$59
$110
$588
$477
$1,144
$19
$2,989
$955
$1,394
$57
$107
$570
$463
$1,110
$19
$2,899
$936
$1,353
$56
$105
$559
$454
$1,088
$18
$2,841
$917
$1,312
$55
$103
$547
$445
$1,066
$18
$2,784
Aero-SmartWay
Aero-SmartWay Advance
Truck
Truck
ClassS DayCab
Class8_DayCab
HighRoof
HighRoof
2-4%
3-5%
$1,107
$2,207
$1,074
$2,207
$1,042
$1,766
$1,011
$1,766
$980
$1,413
$961
$1,370
$941
$1,329
' All vehicle package costs in the table include the proposed application rates of the individual technologies used to establish the proposed standards.
2-93
-------
Regulatory Impact Analysis
Technology
LRR steer tire
LRR drive tire
Weight reduction: Single-
wide tire
Weight reduction:
Aluminum steer wheel
Weight reduction:
Aluminum single- wide
wheel
Air Conditioning Leakage
2014MY Vehicle Package
Applied
to
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck type
ClassS DayCab
ClassS DayCab
Class8_DayCab
Class8_DayCab
Class8_DayCab
ClassS DayCab
Class8_DayCab
Class
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
CO2eq
Effectiveness
1-3%
<1%
<1%
6-7%
2014
$65
$121
$644
$523
$1,254
$21
$3,842
2015
$63
$117
$624
$507
$1,216
$20
$3,754
2016
$61
$114
$606
$492
$1,180
$20
$3,491
2017
$59
$110
$588
$477
$1,144
$19
$3,407
2018
$57
$107
$570
$463
$1,110
$19
$3,185
2019
$56
$105
$559
$454
$1,088
$18
$3,116
2020
$55
$103
$547
$445
$1,066
$18
$3,048
Aero-SmartWay
Aero-SmartWay Advance
LRR steer tire
LRR drive tire
Weight reduction: Single-
wide tire
Weight reduction:
Aluminum steer wheel
Weight reduction:
Aluminum single- wide
wheel
Aux power unit (APU)
Air Conditioning Leakage
2014MY Vehicle Package
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
LowRoof
3-5%
4-7%
1-3%
<1%
5-6%
<1%
12-13%
$1,317
$2,492
$65
$121
$644
$523
$1,254
$5,228
$21
$7,312
$1,277
$2,492
$63
$117
$624
$507
$1,216
$5,071
$20
$7,108
$1,239
$1,994
$61
$114
$606
$492
$1,180
$4,919
$20
$6,810
$1,202
$1,994
$59
$110
$588
$477
$1,144
$4,772
$19
$6,617
$1,166
$1,595
$57
$107
$570
$463
$1,110
$4,628
$19
$6,351
$1,142
$1,547
$56
$105
$559
$454
$1,088
$4,536
$18
$6,221
$1,120
$1,501
$55
$103
$547
$445
$1,066
$4,445
$18
$6,093
Aero-SmartWay
Aero-SmartWay Advance
LRR steer tire
Truck
Truck
Truck
ClassS Sleeper
Cab
ClassS Sleeper
Cab
Class8_Sleeper
MidRoof
MidRoof
MidRoof
3-5%
4-7%
1-3%
$1,345
$2,492
$65
$1,305
$2,492
$63
$1,266
$1,994
$61
$1,228
$1,994
$59
$1,191
$1,595
$57
$1,167
$1,547
$56
$1,144
$1,501
$55
2-94
-------
Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and Effectiveness
Technology
LRR drive tire
Weight reduction: Single-
wide tire
Weight reduction:
Aluminum steer wheel
Weight reduction:
Aluminum single- wide
wheel
Aux power unit (APU)
Air Conditioning Leakage
2014MY Vehicle Package
Applied
to
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck type
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
Class
MidRoof
MidRoof
MidRoof
MidRoof
MidRoof
MidRoof
MidRoof
CO2eq
Effectiveness
<1%
5-6%
<1%
11-12%
2014
$121
$644
$523
$1,254
$5,228
$21
$7,438
2015
$117
$624
$507
$1,216
$5,071
$20
$7,238
2016
$114
$606
$492
$1,180
$4,919
$20
$6,893
2017
$110
$588
$477
$1,144
$4,772
$19
$6,704
2018
$107
$570
$463
$1,110
$4,628
$19
$6,402
2019
$105
$559
$454
$1,088
$4,536
$18
$6,269
2020
$103
$547
$445
$1,066
$4,445
$18
$6,139
Aero-SmartWay
Aero-SmartWay Advance
LRR steer tire
LRR drive tire
Weight reduction: Single-
wide tire
Weight reduction:
Aluminum steer wheel
Weight reduction:
Aluminum single- wide
wheel
Aux power unit (APU)
Air Conditioning Leakage
2014MY Vehicle Package
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
Truck
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
ClassS Sleeper
Cab
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
HighRoof
3-5%
4-7%
1-3%
<1%
5-6%
<1%
15-16%
$1,495
$2,564
$65
$121
$644
$523
$1,254
$5,228
$21
$7,814
$1,450
$2,564
$63
$117
$624
$507
$1,216
$5,071
$20
$7,587
$1,406
$2,051
$61
$114
$606
$492
$1,180
$4,919
$20
$7,316
$1,364
$2,051
$59
$110
$588
$477
$1,144
$4,772
$19
$7,103
$1,323
$1,641
$57
$107
$570
$463
$1,110
$4,628
$19
$6,855
$1,297
$1,591
$56
$105
$559
$454
$1,088
$4,536
$18
$6,716
$1,271
$1,544
$55
$103
$547
$445
$1,066
$4,445
$18
$6,580
2-95
-------
Regulatory Impact Analysis
Table 2-36 Technology Effectiveness and Costs, Inclusive of Markups, by Year for HD Diesel and Gasoline Pickup Trucks & Vans (2008$)
Technology
Low friction
lubricants
Engine friction
reduction
Coupled cam
phasing
Cylinder
deactivation
Stoich GDI V8
8sp AT (relative
to 6sp AT)
Low RR Tires
Aerol
Electric/Electro -
hydraulic Power
steering
DSL engine
improvements
DSL
aftertreatment
improvements
Improved
accessories
Mass Reduction
(5%)
Mass Reduction
(5%)
Mass Reduction
(5%)
Mass Reduction
(5%)
Air
Conditioning
Applied to
All
HD
Gasoline
HD
Gasoline
HD
Gasoline
HD
Gasoline
All
All
All
All
HD Diesel
HD Diesel
HD Diesel
2b
HDGasoline
2b
HDDiesel
o
J
HDGasoline
3 HDDiesel
All
CO2eq
Effectiveness
0-1%
1-3%
1-4%
3-4%
1-2%
1.7%
1-2%
1-2%
1-2%
4-6%
3-5%
1-2%
1.6%
1.6%
1.6%
1.6%
2%
2014
$4
$108
$46
$193
$395
$231
$6
$54
$108
$172
$110
$88
$462
$544
$513
$576
$21
2015
$4
$108
$44
$187
$384
$224
$6
$53
$104
$167
$107
$85
$448
$527
$498
$559
$20
2016
$4
$108
$43
$182
$372
$218
$6
$51
$101
$162
$104
$82
$435
$511
$483
$542
$20
2017
$4
$108
$43
$182
$372
$218
$6
$51
$101
$157
$104
$82
$435
$511
$483
$542
$19
2018
$4
$108
$43
$182
$372
$218
$6
$51
$101
$152
$104
$82
$435
$511
$483
$542
$19
2019
$4
$108
$43
$182
$372
$218
$6
$51
$101
$148
$104
$82
$435
$511
$483
$542
$18
2020
$4
$108
$43
$182
$372
$218
$6
$51
$101
$145
$104
$82
$435
$511
$483
$542
$18
2-96
-------
Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and Effectiveness
Leakage
Overall 20 18
MY Package
12-17%
$1,411
$1,406
$1,350
2-97
-------
Regulatory Impact Analysis
References
1 National Academy of Science. Technologies and Approaches to Reducing the Fuel Consumption of Medium-
and Heavy-Duty Vehicles. March 2010.
2 TIAX, LLC. Assessment of Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles. November
2009.
3 U.S. EPA. EPA Lumped Parameter Model HD Version 1.0.0.5, 2010. Docket #EPA-HQ-OAR-2010-0162.
4 NESCCAF, ICCT, Southwest Research Institute, and TIAX. Reducing Heavy-Duty Long Haul Combination
Truck Fuel Consumption and CO2 Emissions. October 2009.
5ICF International. Investigation of Costs for Strategies to Reduce Greenhouse Gas Emissions for Heavy-Duty
On-Road Vehicles. July 2010. Docket Identification Number EPA-HQ-OAR-2010-0162-0044.
6 Revenue = Direct Costs + Indirect Costs + Net Income
7 RTI International. Heavy Duty Truck Retail Price Equivalent and Indirect Cost Multipliers. July 2010.
8 See "Learning Curves in Manufacturing", L. Argote and D. Epple, Science, Volume 247; "Toward Cost Buy
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9 U.S. EPA and NHTSA, "Final Rulemaking to Establish Light-Duty Vehicle Greenhouse Gas Emission
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viewed on June 3, 2010 at http://www.epa.gov/otaq/climate/regulations/420rl0901.pdf
10 Note that throughout the cost estimates for this HD analysis, the agencies have used slightly higher markups
than those used in the 2010-2016 light-duty FRM. The new, slightly higher ICMs include return on capital of
roughly 6 percent, a factor that was not included in the light-duty analysis.
11 Note that the costs developed for low friction lubes for this analysis reflect the costs associated with any
engine changes that would be required as well as any durability testing that may be required.
12 U.S. EPA and NHTSA, "Final Rulemaking to Establish Light-Duty Vehicle Greenhouse Gas Emission
Standards and Corporate Average Fuel Economy Standards - Joint Technical Support Document," 2010. Last
viewed on June 3, 2010 at http://www.epa.gov/otaq/climate/regulations/420rl0901.pdf
13 Note that throughout the cost estimates for this HD analysis, the agencies have used slightly higher markups
than those used in the 2010-2016 light-duty FRM. The new, slightly higher ICMs include return on capital of
roughly 6 percent, a factor that was not included in the light-duty analysis.
14 Note that the costs developed for low friction lubes for this analysis reflect the costs associated with any
engine changes that would be required as well as any durability testing that may be required.
15 TIAX. Assessment of Fuel Economy Technologies for Medium- and Heavy- Duty Vehicles, Final Report,
Nov. 19,2009, pg4-15.
16 Stanton, Donald. "Enabling High Efficiency Clean Combustion." 2009 Semi-Mega Merit Review of the
Department of Energy. May 21, 2009. Last accessed on August 25, 2010 at
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df.
17 Stanton, Donald. "Enabling High Efficiency Clean Combustion." 2009 Semi-Mega Merit Review of the
Department of Energy. May 21, 2009. Last accessed on August 25, 2010 at
http://wwwl.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2009/advanced_combustion/ace_40_stanton.p
df.
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-------
Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
Effectiveness
18 "Tires and Passenger Vehicle Fuel Economy," Transportation Research Board Special Report 286, National
Research Council of the National Academies, 2006, Docket EPA-HQ-OAR-2009-0472-0146.
19 U.S. EPA and NHTSA, "Final Rulemaking to Establish Light-Duty Vehicle Greenhouse Gas Emission
Standards and Corporate Average Fuel Economy Standards - Joint Technical Support Document," 2010. Last
viewed on June 3, 2010 at http://www.epa.gov/otaq/climate/regulations/420rl0901.pdf
20 U.S.EPA, EPA Lumped Parameter Model HD Version 1.0.0.5, 2010. Docket #EPA-HQ-OAR-2010-0162.
21 Stanton, Donald. "Enabling High Efficiency Clean Combustion." 2009 Semi-Mega Merit Review of the
Department of Energy. May 21, 2009. Last accessed on August 25, 2010 at
http://wwwl.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2009/advanced_combustion/ace_40_stanton.p
df.
22 Zhang, H. Heavy Truck Engine Development & HECC. 2009 DOE Semi-Mega Merit Review, May 21, 2009.
Last accessed on August 25, 2010 at
http://wwwl.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2009/advanced_combustion/ace_42_zhang.pd
f
23 NAS Report. 2010. Pages 53-54.
24 NAS Report. 2010. Page 54.
25 TIAX Report. 2009. Page 3-5.
26 NAS Report. 2010. Page 54.
27 Vuk, C. "Electric Turbo Compounding... A Technology Who's Time Has Come." 2006 DEER Conference.
Last accessed on August 25, 2010 at
http://wwwl.eere.energy.gov/vehiclesandfuels/pdfs/deer_2006/session6/2006_deer_vuk.pdf
28 TIAX, Nov. 19, 2009, page 4-15.
29 Zhang, H. "High Efficiency Clean Combustion for Heavy-Duty Engine." August 6, 2008 presentation to
DEER Conference. Last accessed on August 25, 2010 at
http://wwwl.eere.energy.gov/vehiclesandfuels/pdfs/deer_2008/session5/deer08_zhang.pdf
30 NAS Report. 2010. Page 57.
31 NAS Report. 2010. Page 57.
32 Assumes travel on level road at 65 MPH. (21st Century Truck Partnership Roadmap and Technical White
Papers, December 2006. U.S. Department of Energy, Energy Efficiency and Renewable Energy Program.
21CTP-003. p. 36.)
33 Reducing Heavy-Duty Long Haul Combination Truck Fuel Consumption and CO2 Emissions, ICCT, October
2009
34
SAE 2006-01-3456
35 U.S. EPA. Heavy-Duty Coastdown Test Procedure Development. Docket # EPA-HQ-OAR-2010-0162-0144.
36ICF. Investigation of Costs for Strategies to Reduce Greenhouse Gas Emissions fro Heavy-Duty On-Road
Vehicles. July 2010. Docket Identification Number EPA-HQ-OAR-2010-0162-0044.
37 21st Century Truck Partnership, "Roadmap and technical White Papers", U.S. Department of Energy,
Technical paper: 21CTP-0003, December 2006.
2-99
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Regulatory Impact Analysis
38 "Tires & Truck Fuel Economy," A New Perspective. Bridgestone Firestone, North American Tire, LLC,
Special Edition Four, 2008.
39 "Michelin's Green Meters," Press Kit, October, 30, 2007. http://www.michelin-green-
meter.com/main.php?cLang=en (Complete Press File, Viewed March 6, 2010)
40 "Modeling of Fuel Consumption for Heavy-Duty Trucks and the Impact of Tire Rolling Resistance," Tim J.
LaClair, Russell Truemner, SAE International, 2005-01-3550, 2005.
41 "Factors Affecting Truck Fuel Economy," Goodyear, Radial Truck and Retread Service Manual. Accessed
February 16, 2010 at http://www.goodvear.com/truck/pdf/radialretserv/Retread_S9_V.pdf.
42 "Tire Rolling Resistance, Its Impact on Fuel Economy, and Measurement Standards," Presentation by Tim J.
LaClair of Michelin Americas Research & Development Corp. to the California Energy Commission, 2002.
43 "Technology Roadmap for the 21st Century Truck Program. A Government-Industry Partnership," U.S.
Department of Energy, 21CT-001, December 2000.
44 "Energy Efficiency Strategies for Freight Trucking: Potential Impact on Fuel Use and Greenhouse Gas
Emissions," J. Ang-Olson, W. Schroer, Transportation Research Record: Journal of the Transportation Research
Board, 2002(1815): 11-18.
45 "j7ffecj Of singie wide Tires and Trailer Aerodynamics on Fuel Economy and NOx Emissions of Class 8
Line-Haul Tractor-Trailer," J. Bachman, A. Erb, C. Bynum, U.S. Environmental Protection Agency, SAE
International, Paper Number 05CV-45, 2005.
46 "Class 8 Heavy Truck Duty Cycle Project Final Report," U.S. Department of Energy, Oak Ridge National
Laboratory, ORNL/TM-2008/122, p. 21, December 2008. Accessed January 19, 2010 at
http://cta.ornl.gov/cta/Publications/Reports/ORNL TM 2008-122.pdf.
47 "Are Ultra-Wide, Ultra-Low Aspect Ratio Tires the Next Big Thing?" K. Rohlwing, Today's Tire Industry,
Vol. 1, Issue 1, July/August, July 2003.
48 "New Generation Wide Base Single Tires," American Trucking Association, White paper presented at the
International Workshop on the use of wide tires sponsored by Federal Highway Administration, Turner-Fairbank
Highway Research Center, October 25-26, 2007, Revision 9, December 21, 2007, Accessed on February 3, 2010
athttp://www.arc.unr.edu/Workshops/Wide_Tires/Wide_Base_Summary-v9-ATA-whitepaper.pdf
49 "Recommended Practice: Guidelines for Outset Wide Base Wheels for Drive, Trailer and Auxiliary Axle
Applications (Draft)," Technology and Maintenance Council, Council of American Trucking Associations,
circulated September 28, 2009.
50ICF. Investigation of Costs for Strategies to Reduce Greenhouse Gas Emissions fro Heavy-Duty On-Road
Vehicles. July 2010. Docket Identification Number EPA-HQ-OAR-2010-0162-0044.
51 "Buses & Retread Tires," The Tire Retread & Repair Information Bureau, Pacific Grove, Ca., Accessed on
January 27, 2010 at http://www.retread.org/packet/index.cfm/ID/284.htm.
52 "What are Retreaders Doing to Improve Fuel Efficiency?" H. Inman, Tire Review, December 11, 2006,
Accessed on February 18, 2010 at
http://www.tirereview.com/Article/59777/what are retreaders doing to improve fuel efficiencv.aspx.
53 "Better Fuel Economy? Start with a Strong Tire Program," H. Inman, Fleet & Tire 2006, Tire Review,
December 11, 2006, Accessed on February 18, 2010 at
http://www.tirereview.com/Article/59776/better fuel economy start with a strong tire_program.aspx.
54 "SmartWay Transport Partnership: Innovative Carrier Strategies", February 2004, EPA420-F-04-005,
Accessed on the Internet on January 18, 2010 at: http://www.epa.gov/smartway/transport/what-smartway/carrier-
strategies.htm#weight.
2-100
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
Effectiveness
55 "Energy Savings through Increased Fuel Economy for Heavy Duty Trucks", Therese Langer, American
Council for an Energy-Efficient Economy prepared for the National Commission on Energy Policy, February 11,
2004.
56 "The Potential Effect of Future Energy-Efficiency and Emissions-Improving Technologies on Fuel
Consumption of Heavy Trucks", Argonne National Laboratory, Technical Report ANL/ESD/02-4, August 2002.
57 U. S. EPA. http ://www. epa. gov/smartway/documents/weightreduction.pdf
58 U.S. EPA. http://www.epa.gov/smartway/documents/weightreduction.pdf
59 Gaines, L. and D. Santini. Argonne National Laboratory, Economic Analysis of Commercial Idling Reduction
Technologies
60 Gaines, L., A. Vyas, J. Anderson. Estimation of Fuel Use by Idling Commercial Trucks. 2006. Page 9.
Gaines, L., A. Vyas, J. Anderson. Estimation of Fuel Use by Idling Commercial Trucks. 2006. Page 7.
62 NAS Study. 2010. Page 122 says the best in class APU consumes 0.18 gallon per hour.
63 American Trucking Association. Last viewed on January 29, 2010 at
http://www.trucksdeliver.org/recommendations/speed-limits.html
64 U.S. EPA SmartWay Transport Partnership. Last viewed on January 28, 2010 at
http://www.epa.gov/smartway/transport/documents/tech/reducedspeed.pdf
65 Department for Transport, Vehicle and Operator Services Agency. Last viewed on January 6, 2010 at
http://www.dft.gov.uk/vosa/newsandevents/pressreleases/2006pressreleases/28-12-06speedlimiterlegislation.htm
66 Transport Canada. Summary Report - Assessment of a Heavy Truck Speed Limiter Requirement in Canada.
Last viewed on January 6, 2010 at http://www.tc.gc.ca/eng/roadsafety/tp-tpl4808-menu-370.htm
67 Transport Canada. Summary Report - Assessment of a Heavy-Truck Speed Limiter Requirement in Canada.
68 "Assessment of Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles", TIAX LLC, November
19,2009. Page 4-98.
69 "Assessment of Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles", TIAX LLC, November
19,2009. Page 4-98.
70 US Environmental Protection Agency's SmartWay Transport Partnership July 2010 e-update accessed July
16, 2010, from http://www.epa.gov/smartwavlogistics/newsroom/documents/e-update-julv-10.pdf
71 TIAX. Assessment of Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles. November 2009.
Page 4-40.
72 U.S. Department of Energy. Transportation Energy Data Book, Edition 28-2009. Table 5.7.
73 As explained further in Section V below, EPA would use these inputs in GEM even for engines electing to use
the alternative engine standard.
74 US Environmental Protection Agency's SmartWay Transport Partnership July 2010 e-update accessed July
16, 2010, from http://www.epa.gov/smartwavlogistics/newsroom/documents/e-update-july-10.pdf
75 Rubber Manufacturers Association. Presentation to California Air Resource Board. June 2009. Last viewed
at
http://www.rma.org/rma_resources/government_affairs/federal_issues/RMA%20COMMENTS%20APPENDIX
%201%20-%20ENVIRON%20Report%20-%20Data%20Analysis.pdf
2-101
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Regulatory Impact Analysis
76 Kargul, J. J., 2010, "Clean Automotive Technology. Cost-Effective Solutions for a Petroleum and Carbon
Constrained World," Presentation made to National Academy of Sciences, Review of 21st Century Truck
Program, September 8, 2010
77 "Best practices Guidebook for Greenhouse Gas Reductions in Freight Transportation", H. Christopher Fey,
Po-Yao Kuo, North Carolina State University prepared for the U.S. Department of Transportation, October 4,
2007.
78 "Reducing Heavy-Duty long haul Combination Truck Fuel Consumption and CO2 Emissions", NESCCAF,
ICCT, SwRI, TIAX LLC, October 2009.
79 The U.S. EPA has reclamation requirements for refrigerants in place under Title VI of the Clean Air Act.
80 The global warming potentials (GWP) used in the NPRM analysis are consistent with Intergovernmental Panel
on Climate Change (IPCC) Fourth Assessment Report (AR4). At this time, the IPCC Second Assessment Report
(SAR) global warming potential values have been agreed upon as the official U.S. framework for addressing
climate change. The IPCC SAR GWP values are used in the official U.S. greenhouse gas inventory submission
to the climate change framework. When inventories are recalculated for the final rule, changes in GWP used
may lead to adjustments.
81 Schwarz, W., Hamisch, J. 2003. "Establishing Leakage Rates of Mobile Air Conditioners." Prepared for the
European Commission (DG Environment), Doc B4-3040/2002/337136/MAR/C1.
82 Vincent, R., Cleary, K., Ayala, A., Corey, R. 2004. "Emissions of HFC-134a from Light-Duty Vehicles in
California." SAE 2004-01-2256.
83 The Minnesota refrigerant leakage data can be found at
http://www.pca. state.mn.us/climatechange/mobileair.html#leakdata.
84 Society of Automotive Engineers, "IMAC Team 1 - Refrigerant Leakage Reduction, Final Report to
Sponsors," 2006.
85 Society of Automotive Engineers Surface Vehicle Standard J2727, issued August 2008, http://www.sae.org.
86 U.S. Department of Transportation, Federal Highway Administration. Federal Highway Statistics. "Trailer
and Semitrailer Registrations - 2008" Table MV-11 located at
www.fhwa.dot.gov/policyinformation/statistics/2008/mvl 1 .cfm
87
The International Council on Clean Transportation. Heavy Duty Vehicle Market Analysis. May 2009. Table
88Trailer Body Builders. Last viewed on August 18, 2010 at http://trailer-bodybuilders.com/trailer-
output/output/2008_trailer_output_table/
89ICF. Investigation of Costs for Strategies to Reduce Greenhouse Gas Emissions fro Heavy-Duty On-Road
Vehicles. July 2010. Docket Identification Number EPA-HQ-OAR-2010-0162-0044.
90 "Review of Low Carbon Technologies for Heavy Goods Vehicles - Annex 1", Ricardo prepared for
Department of Transport, Technology Paper RD.09/182601.7, Jun 2009
91 U.S. Environmental Protection Agency Office of Transportation and Air Quality SmartWay Transport
Partnership, A Glance at Clean Freight Strategies: Drivers Training EPA 420-F-04-008; February 2004.
92 Ibid.
93 National Research Council, Technologies and Approaches to Reducing the Fuel Consumption of Medium- and
Heavy-Duty Vehicles, Committee to Assess Fuel Economy Technologies for Medium- and Heavy-Duty
Vehicles; Washington, DC, National Academies Press, 2010.
94 Information from US EPA review of 2009 SmartWay Excellence Awards applications.
2-102
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Heavy Duty GHG and Fuel Efficiency Standards NPRM: Technologies, Cost, and
Effectiveness
95 U.S. Environmental Protection Agency Office of Transportation and Air Quality SmartWay Transport
Partnership, A Glance at Clean Freight Strategies: Drivers Training EPA 420-F-04-008; February 2004.
96 National Research Council, Technologies and Approaches to Reducing the Fuel Consumption of Medium- and
Heavy-Duty Vehicles, Committee to Assess Fuel Economy Technologies for Medium- and Heavy-Duty
Vehicles; Washington, DC, National Academies Press, 2010.
97 Technology and Maintenance Council of the American Trucking Associations, Tire Air Pressure Study, Tire
Debris Prevention Task Force S.2 Tire & Wheel Study Group; May 2002.
98 National Research Council, Technologies and Approaches to Reducing the Fuel Consumption of Medium- and
Heavy-Duty Vehicles, Committee to Assess Fuel Economy Technologies for Medium- and Heavy-Duty
Vehicles; Washington, DC, National Academies Press, 2010.
99 U.S. Environmental Protection Agency Office of Transportation and Air Quality SmartWay Transport
Partnership, A Glance at Clean Freight Strategies: Automatic Tire Inflation Systems EPA 420-F-04-0010;
February 2004.
100 National Research Council, Technologies and Approaches to Reducing the Fuel Consumption of Medium-
and Heavy-Duty Vehicles, Committee to Assess Fuel Economy Technologies for Medium- and Heavy-Duty
Vehicles; Washington, DC, National Academies Press, 2010.
101 Ibid.
102 "Comprehensive Truck Weight and Size Study: Summary Report," U.S. DOT Federal Highway Traffic
Administration, August 2000.
103 "Comprehensive Truck Weight and Size Study: Summary Report," U.S. DOT Federal Highway Traffic
Administration, August 2000.
104 "Comprehensive Truck Weight and Size Study: Summary Report," U.S. DOT Federal Highway Traffic
Administration, August 2000.
105 National Research Council, Technologies and Approaches to Reducing the Fuel Consumption of Medium-
and Heavy-Duty Vehicles, Committee to Assess Fuel Economy Technologies for Medium- and Heavy-Duty
Vehicles; Washington, DC, National Academies Press, 2010.
2-103
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
Chapter 3: Test Procedures
Test procedures are a crucial aspect of the proposed heavy-duty vehicle GHG and fuel
consumption program. The proposed rulemaking is establishing several new test procedures for
both engine and vehicle compliance. This chapter will describe the development process for the
test procedures being proposed, including the assessment of engines, aerodynamics, rolling
resistance, chassis dynamometer testing, and drive cycles.
3.1 Heavy-Duty Engine Test Procedure
The agencies are proposing to control heavy-duty engine fuel consumption and
greenhouse gas emissions through the use of engine certification. The proposed program will
mirror existing engine regulations for the control of non-GHG pollutants in many aspects. The
following sections provide an overview of the proposed test procedures.
3.1.1 Existing Regulation Reference
Heavy-duty engines currently are certified for non-GHG pollutants using test procedures
developed by EPA. The Heavy-Duty Federal Test Procedure is a transient test consisting of
second-by-second sequences of engine speed and torque pairs with values given in normalized
percent of maximum form. The cycle was computer generated from a dataset of 88 heavy-duty
trucks in urban operation in New York and Los Angeles. These procedures are well-defined and
we believe appropriate also for the assessment of GHG emissions. EPA is concerned that we
maintain a regulatory relationship between the non-GHG emissions and GHG emissions,
especially for control of CC>2 and NOX. Therefore, we are proposing to use the same test
procedures.
For 2007 and later Heavy-Duty engines, Parts 86 - "Control of Emissions from New and
In-Use Highway Vehicles and Engines" and 1065 - "Engine Testing Procedures" detail the
certification process. Part 86.007-11 defines the standard settings of Oxides of Nitrogen, Non-
Methane Hydrocarbons, Carbon Monoxide, and Particulate. The duty cycles are defined in Part
86. The Federal Test Procedure engine test cycle is defined in Part 86 Appendix I. The
Supplemental Emissions Test engine cycle is defined in §86.1360-2007(b). All emission
measurements and calculations are defined in Part 1065, with exceptions as noted in §86.007-11.
The data requirements are defined in § 86.001-23 and 1065.695.
The procedure for CC>2 measurement is presented in §1065.250. For measurement of
CH4 refer to §1065.260. For measurement of N2O refer to §1065.275. We recommend that you
use an analyzer that meets performance specifications shown in Table 1 of §1065.205. Note that
your system must meet the linearity verification of §1065.307. To calculate the brake specific
mass emissions for CC>2, CH4 and N2O refer to §1065.650. For CH4 refer to §1065.660(a) to
calculate the contamination correction.
5-1
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Draft Regulatory Impact Analysis
3.1.2 Engine Dynamometer Test Procedure Modifications
3.1.2.1 Fuel Consumption Calculation
EPA and NHTSA propose to calculate fuel consumption, as defined as gallons per brake
horsepower-hour, from the CC>2 measurement. The agencies are proposing that manufacturers
use 8,887 gram of CC>2 per gallon of gasoline and 10,180 g CO2 per gallon of diesel fuel.
3.1.2.2 N2O Measurement
EPA proposes that manufacturers would need to submit measurements of N2O to be able
to apply for a certificate of conformity with the N2O standard. Engine emissions regulations do
not currently require testing for N2O, and most test facilities do not have equipment for its
measurement. Manufacturers without this capability would need to acquire and install
appropriate measurement equipment. For use commencing with MY 2015 engines and vehicles,
EPA is proposing four N2O measurement methods, all of which are commercially available
today. EPA expects that most manufacturers would use photo-acoustic measurement equipment,
which the Agency estimates would result in a one-time cost of about $50,000 for each test cell
that would need to be upgraded.
3.1.2.3 COi Measurement Variability
EPA and NHTSA evaluated two means to handle the CO2 and fuel consumption
measurement variability. The first is to use an approach similar to the LD GHG and Fuel
Economy program where the agencies adopted a compliance factor that is applied to the
measured value. The second is an approach where the standard is set as a not to exceed standard.
Manufacturers set a design target set sufficiently below the standard to account for production
variability and deterioration.
The agencies are proposing to take an approach where manufacturers are allowed to
determine their own compliance margin, but it must be at least two percent to account for the
test-to-test variation. The agencies developed the two percent threshold based on CO2
measurement variability from several test programs. The programs include internal EPA round-
robin testing, ACES1, and the Gaseous MA program.2 Table 3-1 summarizes the results from
each of these programs.
5-2
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
Table 3-1: Summary of CO2 Measurement Variability
ENGINE
AFTERTREATMENT
TEST SITE
TEST
#OF
TESTS
CoV (%)
Same Engine - Same Test Cell - Different Days
11L
11L
11L
9L
12L
12L
6.7L
13L
14L
14L
14L
14L
Engine A
Engine B
Engine C
Engine D
DPF
DPF
DPF
No DPF
No DPF
No DPF
No DPF
DPF
DPF
DPF
DPF
DPF
DPF
DPF
DPF
DPF
EPAHD05
EPA HD05
EPAHD05
EPA HD05
EPAHD01
EPA HD05
EPAHD02
EPA HD05
SwRI
SwRI
CE-CERT
CE-CERT
SwRI (ACES)
SwRI (ACES)
SwRI (ACES)
SwRI (ACES)
Hot Transient
RMC
Cold/Soak/Hot
8 Mode
Hot Transient
Hot Transient
FTP
FTP
NTE
13 Mode SET
NTE
13 Mode SET
FTP
FTP
FTP
FTP
10
7
3
7
8
31
12
11
9
6
9
6
3
o
J
3
o
J
0.22%
0.12%
0.02%
0.44%
0.09%
1.37%
0.67%
0.37%
0.2%
0.2%
0.5%
0.5%
0.1%
0.4%
0.6%
0.5%
Same Engine - Different Test Cells - Different Days
12L
14L
14L
No DPF
DPF
DPF
EPAHD01&
HD05
SwRI & CE-
CERT
SwRI & CE-
CERT
Hot Transient
NTE
13 Mode SET
39
18
12
1.58%
1.4%
1.2%
3.1.2.4 Regeneration Impact on
The current engine test procedures also require the development of regeneration emission
rate and frequency factors to account for the emission changes during a regeneration event.3 We
are proposing to exclude the CO2 emissions due to regeneration. Our assessment of the current
non-GHG regulatory program indicates that engine manufacturers are already highly motivated
to reduce the frequency of regeneration events due to the significant impact on NOX emissions.
In addition, market forces already exist which create incentives to reduce fuel consumption
during regeneration. EPA is proposing the exclusion of CC>2 emissions during regeneration;
however, we consider the existing regulations, as described below, as a potential alternative.
As described in §86.001-24(1), emission results from heavy-duty engines equipped with
aftertreatment systems may need to be adjusted to account for regeneration events. This is
particularly true if these regenerations are expected to occur on a frequency of less than once per
transient test cycle. Regeneration of exhaust aftertreatment devices commonly involves increases
in fueling rate to raise exhaust temperature or lower exhaust oxygen content. While the impact of
a regeneration event on criteria pollutant emissions (i.e. CO, NOX, PM, HC) varies, regeneration
is more likely to increase CO2 emissions and therefore must be considered.
5-3
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Draft Regulatory Impact Analysis
The current regulations outline a method of accounting for changes in emissions due to
regeneration events (§86.001-24(i)(l)-(i)(5)). This method involves developing downward and
upward adjustment factors (D/UAFs) meant to characterize emissions with and without
(respectively) a regeneration event. Combined with a frequency factor (F), characterizing the
frequency at which regeneration occurs, these adjustments are applied to the final emission test
results. Use of this procedure to account for changes in CC>2 emissions during regeneration
appears to be a practical, well accepted, and accurate method for certification. Any increases (or
decreases) in CC>2 due to regeneration would be captured in the adjustment factors and final
emission results could be corrected accordingly.
3.1.2.5 Fuel Heating Value Correction
The agencies collected baseline CO2 performance of diesel engines from testing which
used fuels with similar properties. The agencies are proposing a fuel-specific correction factor
for the fuel's energy content in case this changes in the future. The agencies found the average
energy content of the diesel fuel used at EPA's National Vehicle Fuel and Emissions Laboratory
was 21,200 BTU per pound of carbon. This value is determined by dividing the Net Heating
Value (BTU per pound) by the carbon weight fraction of the fuel used in testing.
The existing regulations correct for gasoline fuel properties, as described in Part 86. The
same correction can be used for the testing of complete pickup trucks and vans with gasoline
fueled engines.
The agencies are not proposing fuel corrections for alcohols because the fuel chemistry is
homogeneous. The agencies are proposing a fuel correction for natural gas.
3.1.2.6 Multiple Fuel Maps
Modern heavy-duty engines may have multiple fuel maps, commonly meant to improve
performance or fuel economy under certain operating conditions. CC>2 emissions can also be
different depending on which map is tested, so it is important to specify a procedure to properly
deal with engines with multiple fuel maps. Consistent with criteria-pollutant emissions
certification, engine manufacturers should submit CC>2 data from all fuel maps on a given test
engine. This includes fuel map information as well as the conditions under which a given fuel
map is used (i.e. transmission gear, vehicle speed, etc).
3.1.3 Engine Family Definition and Test Engine Selection
3.1.3.1 Criteria for Engine Families
The current regulations outline the criteria for grouping engine models into engine
families sharing similar emission characteristics. A few of these defining criteria include bore-
center dimensions, cylinder block configuration, valve configuration, and combustion cycle; a
comprehensive list can be found in §86.096-24(a)(2). While this set of criteria was developed
with criteria pollutant emissions in mind, similar effects on CC>2 emissions can be expected. For
this reason, this methodology should continue to be followed when considering CC>2 emissions.
5-4
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
3.1.3.2 Emissions Test Engine
Manufacturers must select at least one engine per engine family for emission testing. The
methodology for selecting the test engine(s) should be consistent with §86.096-24(b)(2) (for
heavy-duty Otto cycle engines) and §86.096-24(b)(3) (for heavy-duty diesel engines). An
inherent characteristic of these methodologies is selecting the engine with the highest fuel feed
per stroke (primarily at the speed of maximum rated torque and secondarily at rated speed) as the
test engine, as this is expected to produce the worst-case criteria pollutant emissions. CO2
emissions are expected to scale well with fuel feed in a given engine family and therefore work-
based CC>2 measurements are expected to be less sensitive to the specific engine model selected
than criteria pollutant emissions. To be consistent however, it is recommended that the same
methodology continue to be used for selecting test engines.
3.2 Aerodynamic Assessment
The aerodynamics of a Class 7/8 combination tractor is dependent on many factors,
including the tractor design, trailer design, gap between the tractor and trailer, vehicle speed,
wind speed, and many others. We believe that to fairly assess the aerodynamics of combination
tractors certain aspects of the truck need to be defined, including the trailer, location of payload,
and tractor-trailer gap.
3.2.1 Standardized Trailer Definition
We are proposing to use a model input reflecting a standardized trailer for each
subcategory of the Class 7/8 tractor subcategories based on tractor roof height. High roof
tractors are designed to optimally pull box trailers. The height of the roof fairing is designed to
minimize the height differential between the tractor and typical trailer to reduce the air flow
disruption. Low roof tractors are designed to carry flatbed or low-boy trailers. Mid roof tractors
are designed to carry tanker and bulk carrier trailers. High roof tractors are designed to
optimally pull box trailers. However, we recognize that during actual operation tractors
sometimes pull trailers that do not provide the optimal roof height that matches the tractor. In
order to assess how often truck and trailer mismatches are found in operation, EPA conducted a
study based on observations of traffic across the U.S.4 Data was gathered on over 4,000 tractor-
trailer combinations using 33 live traffic cameras in 22 states across the United States.
Approximately 95% of trucks were "matched" per our definition (e.g. box trailers were pulled by
high roof tractors and flatbed trailers were pulled with low roof tractors). The amount of
mismatch varied depending on the type of location. Over 99% of the tractors were observed to
be in matched configuration in Indiana at the I-80/I-94/I-65 interchange, which is representative
of long-haul operation. On the other hand, only about 90% of the tractors were matched with the
appropriate trailer in metro New York City, where all mismatches consisted of a day cab and a
tall container trailer. The study also found that approximately 3% of the tractors were traveling
without a trailer or with an empty flatbed. The agencies therefore conclude that given this very
limited degree of mismatch, we can use a standardized definition which optimizes tractor-trailer
matching.
Section 1037.510 prescribes the proposed standardized trailer for each tractor
subcategory (low, mid, and high roof) including trailer dimensions and tractor-trailer gap.
5-5
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Draft Regulatory Impact Analysis
3.2.2 Aerodynamic Assessment
The aerodynamic drag of a vehicle is determined by the vehicle's coefficient of drag
(Cd), frontal area, air density and speed. The agencies are proposing to define the input
parameters to GEM which represent the frontal area and air density, while the speed of the
vehicle would be determined in GEM through the proposed drive cycles. The agencies are
proposing that the manufacturer would determine a truck's Cd, a dimensionless measure of a
vehicle's aerodynamics, through testing which then would be input into the GEM model.
Quantifying truck aerodynamics as an input to the GEM presents technical challenges because of
the proliferation of truck configurations and the lack of a common industry-standard test method.
Class 7/8 tractor aerodynamics are currently developed by manufacturers using coastdown
testing, wind tunnel testing and computational fluid dynamics. The agencies are proposing to
allow manufacturers to use any of these three aerodynamic evaluation methods.
3.2.2.1 Coastdown Testing
For several decades, light-duty vehicle manufacturers have performed coastdown tests
prior to vehicle certification. However, this practice is less common with heavy-duty vehicles,
since the current heavy-duty certification process focuses on engine and not vehicle exhaust
emissions, i.e., NOx, PM, NMHC, CO. In recent years, growing concerns over energy security,
fuel efficiency and carbon footprint have prompted efforts to develop and improve design
features or technologies related to the aerodynamic and mechanical components of heavy-duty
(HD) vehicles. Lowering tire rolling resistance, aerodynamic drag, and driveline parasitic losses
on HD vehicles could translate into significant long-term fuel savings as well as HD greenhouse
gas emissions reductions, since vehicles with enhanced aerodynamic or mechanical features
encounter lower road load force during transport, and thereby consume less fuel. The road load
force can be captured by coasting a vehicle along a flat straightaway under a set of prescribed
conditions. Such coastdown tests produce vehicle specific coastdown coefficients describing the
road load as a function of vehicle speed.
The coefficients obtained are essential parameters for conducting chassis dynamometer
tests as well as for assessing GHG and fuel consumption performance for Class 7/8 combination
tractors via modeling. Because the existing coastdown test protocols, i.e., SAE J1263and SAE
J2263, were established primarily from the light-duty perspective, the agencies realize that some
aspects of this methodology might not be applicable or directly transferable to heavy-duty tractor
applications.5'6 Therefore, it appears that some modifications to existing light-duty vehicle-
focused coastdown protocols are necessary. Sections 3.2.2.1.1 and 3.2.2.2.2 describe the
existing protocols and our proposed modifications to the protocols, respectively.
3.2.2.1.1 Overview of SAE J2263
The Society of Automotive Engineers (SAE) publishes voluntary reports to advance the
technical and engineering sciences. The SAE Technical Standards Board, in the J2263 DEC2008
Surface Vehicle Recommended Practice publication, established a procedure for determination
of vehicle road load force using onboard anemometry and coastdown techniques.
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_ Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
The coastdown runs need to be conducted on a dry and level road, under no rain or fog
conditions, at an ambient temperature between 5 to 35°C (41 to 95°F), and average wind speed
less than 35 km/h (21.7 mi/h) with wind gusts less than 15 km/h (31.3 mi/h) and average cross
winds less than 15 km/h (9.3 mi/h).
The vehicle and tires should have a preferable break-in of 6500 km (4039 mi) prior to
testing, and a minimum of 3500 km (2175 mi). The tire pressure must be set and recorded before
moving the vehicle. The vehicle and tires require preconditioning for a minimum of 30 minutes
running at 80 km/h (49.7 mi/h). Calibration of the instrumentation can be done during
preconditioning.
The vehicle's windows and vents must be closed and the use of any accessory that can
affect the engine speed shall be noted and duplicated during any subsequent dynamometer
adjustments.
The recommended relative wind speed and direction measurement location is at the
approximate mid-point of the vehicle's frontal cross section and about 2 meters in front of it.
A minimum of 10 valid runs, 5 in each alternating direction, must be made. For each run
the vehicle is accelerated to a speed of 125 km/h (77.7 mi/h) for heavy-duty vehicles, the
transmission is shift into neutral gear, and measurements are taken until the vehicle speed
reaches 15 km/h (9.3 mi/h). Engage the transmission and accelerate for the next run; try to
minimize the time between runs to avoid vehicle and ambient variations.
Lane changes should be avoided, and the run should be voided if a passing vehicle in the
same direction comes within 200 meters from the leading or trailing end of the vehicle. Traffic
moving in the adjacent lane in opposite direction is fine. For tracks that are too short, "split"
coastdown runs are allowed to form a complete run.
Data from the "split" runs should be knitted by taking the information recorded for the
coastdown from the 100 km/h (62.2 mi/h) speed to speed X, and the information recorded from
speed X to the 15 km/h (9.3 mi/h) speed.
The mass of the vehicle is recorded at the end of the test; including instrumentation,
driver and any passengers.
The road load force model is a function of vehicle speed, relative wind speed and yaw
angle. The model will calculate road force for vehicle speeds between 100 km/h (62.2 mi/h) and
15 km/h (9.3 mi/h).
The mechanical drag is modeled as a three-term polynomial with respect to speed (V):
Where A, B, and C coefficients are determined by fitting the data into the polynomial
curve.
5-7
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Draft Regulatory Impact Analysis
The aerodynamic drag is modeled as a five-term polynomial with respect to the yaw
angle (Y) in degrees:
Daero = '/2 * p * A * Vr2 * (a + b*Y + c*Y2 + d*Y3 + e*Y4)
o 9
Where p is the air density (kg/m ), A is the vehicle's frontal area (m ), Vr is the relative
wind velocity (km/h), and a, b, c, d, and e coefficients are determined by fitting the data into the
polynomial curve.
The test asks for a level surface, but if the track is not level, the force contribution due to
gravity is:
Dgrav=±M*g*(dh/ds)
Where the plus sign is up and minus is down, M is the mass of the vehicle, g is gravity,
and (dh/ds) is the change in elevation per distance along the track.
The equation of motion is:
-Me*(dV/dt) = Dmech + Daero +Dffm
Where Me is the effective vehicle mass, and (dV/dt) is the vehicle velocity as a function
of time.
The road load force equation used by EPA is:
Road Load Force = Amech + Bmech*V+ Ctoti*V2
Where Amech, Bmech and Ctoti are values obtained from the analysis of the data done by
SAE program and V is the vehicle speed.
3.2.2.1.2 Proposed Modifications to SAE J2263
The agencies have assessed the feasibility of performing coastdown testing on heavy-
duty trucks, primarily on Class 7/8 combination tractors. EPA, through its contractor Southwest
Research Institute, conducted coastdown tests using SAE test methods J1263 and J2263 on three
SmartWay-certified Class 8 tractor-trailers equipped with sleeper cabs during the period October
2008 through November 2009. Also, other contractors, Transportation Research Center in Ohio
and Automotive Testing and Development Inc. in California performed coastdown testing for the
agencies on up to two dozen Class 2b-8 truck configurations in 2009-2010. EPA also gained
firsthand experience of such testing by performing its own coastdown testing on one Class 6 and
multiple Class 8 truck configurations at nearby locations using both SAE test methods. Details
regarding these tests can be found in "Heavy-Duty Coastdown Test Procedure Development"
Docket Number EPA-HQ-OAR-2010-0162-0144.7
Based on our ongoing experiences with Class 7/8 combination tractor coastdown testing
and our consultation with light-duty coastdown expert Peter Janosi, we propose the following for
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
a heavy-duty coastdown test procedure; details on how we reached our determination through
coastdown data analysis are presented below.
• Vehicle Testing
o Conduct SAE J2263 with more runs. EPA recommends that 10 pairs be run for a
total of 20 tests. Since heavy-duty coastdowns involve more uncertainty, more
tests are required to achieve and acceptable certainty in the mean of the resulting
coefficients. Abide all road and weather restrictions given in the SAE J2263
standard.
o For safety reasons, because EPA was conducting its coastdown on roadways,
EPA modified the high speed procedure running at vehicle speeds between 100
km/h (62.2 mi/h) and 15 km/h (9.3 mi/h).
o Calibration runs can be conducted at constant 50 mi/h in each road direction,
immediately back-to-back so as to minimize changes in weather/average wind
speed
o Split runs can be used, but whole runs are preferred.
o J2263 states that consecutive runs shall be made in opposite directions; however,
to reduce our presence on state and county roads and run more tests during core
testing hours, EPA ran two to four consecutive tests (depending on the vehicle
class) in the same direction and accounted for this in the analysis; we are
proposing this modification to J2263 as an option.
• Data Analysis
o Use Equation 2 for yaw angle correction
o Use Equation 1 for wind speed correction
o Use MM5 for road load mean and uncertainty determination. If E is not
statistically significant, then use MM6.
o Correct regression coefficients for ambient temperature and ambient pressure as
per SAE J2263
o Use Equation 12 to determine rolling resistance coefficient
3.2.2.1.3 Mixed Model Analysis with SAS
As al ready m entioned, t he a gencies co nducted s everal co astdown t esting p rograms t o
evaluate the feasibility of Class 7/8 combination tractor coastdown testing. This section details
the process which we undertook upon ge nerating or receiving coastdown data files. F irst, we
determined which runs were valid, based on i nstrument readings, weather, and other criteria.
During travel, air will "pile up" near the front of the tractor. This causes our anemometer wind
speed readings to be offset from actual wind speed. T o correct for this, we calculated the ratio
between the vehicle speed and measured wind speed at each time interval. We then averaged the
ratio by run direction. We then averaged each run direction's ratio for each date and applied this
ratio back to the measured wind speed to estimate actual wind speed.
5-9
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Draft Regulatory Impact Analysis
Equation 1
v =—v
2r,meas,dir,i / j
dir
i,di
We observed an offset to the anemometer's wind direction measurements. We corrected
this by assuming that at high speeds, wind direction is head-on (zero degrees). For each date, we
averaged the first five seconds (25 measurements for 5-hz data) of wind direction for each run
direction. We then averaged the two directions' average. We then subtracted the resulting value
from all of the measured wind direction values to get our correct wind direction.
Equation 2
7 =7
dir
n.
-Y7
/ j meas,dir,i
In general, the J2263 analysis method and equations were used as a foundation for this analysis:
/T7" JJ
Equation 3 -Me — = Am+BmV + CmV2 + DVr2 (a0 + a,Y + a2Y2 + a3Y3 + a474) ±Mg—
dt ds
We us ed a m ixed m odel (through S AS® s oftware) tod escribe our 5 -hz da ta w ith t he
above equation. A mixed model allows us to accurately predict the mean coefficients for each
vehicle, while accounting for the scatter within each run and also the run-to-run variability when
determining t he s tandard e rror of t he c oefficient e stimates. T his t akes i nto a ccount t hat
measurements are not independent within each run, but each run is independent from all other
runs.
The e quations be low r epresent t he ve rsions of Equation 3 we m odeled tod etermine
means and significances of each of the variables. As an initial simplification, aj, aj, and a^ were
eliminated in a 11 ite rations s ince wed etermined th at yaw a ngle d id n ot v ary enough d uring
testing to warrant such a complex polynomial characterization. W e also set a0=l so that the
drag coefficient could be characterized by the D term. Since our elevation change was negligible
in the stretch of road on which we conducted coastdowns, the grade term was also eliminated for
all runs. The following mixed models were run:
3-10
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
Equation 4
Equation 5
-M, — = Am + BmV + CmV2 + DV2(\ + a272), rewritten as
dt
dt
' + CmV2 + DV2 + EV2Y2, where a2 = E/D
MM1
Equation 6
dV_
dt
m m m
MM2
Equation 7
dV
r r
MM3
Equation 8
dt
MM4
Equation 9
MM5
Equation 10
MM6
Based on statistical significance of the various effects, one of the mixed models was
chosen as the model to appropriately determine the road load coefficients. For heavy-duty
trucks, this was usually MM6.
3.2.2.1.4
Use of the Data for Modeling
In each m ixed m odel ( MM1-MM6), w e f ound t hat t he Bm, Cm, a nd E were n ot
consistently significant from zero. As examples, models MM4 and MM6 are described below.
In MM4, the results consistently show that Bm is not significant from zero. Table 3 -2
summarizes these results. The inclusion of Bm often causes the estimates and uncertainties of the
other terms to vary.
3-11
-------
Draft Regulatory Impact Analysis
Table 3-2 - Mixed Model MM4 Shows No Significant Road Load Linear with Vehicle Speed.
Date
5-Aug-09
6-Aug-09
1-Sep-09
2-Sep-09
3-Sep-09
18-Sep-09
23-Sep-09
24-Sep-09
25-Sep-09
Truck configuration
(tractor_trailer_payload)
FL60_N/A_full
FL60_N/A_full
lnt'l_flatbed_full
lnt'l_flatbed_full
lnt'l_flatbed_full
lnt'l_flatbed_half
lnt'l_flatbed_empty
lnt'l_box_full
lnt'l_box_full
Am [Ib]
153.8
137.7
490.5
483.3
551.5
372.2
226.3
521.5
495.7
% Std
err
7.75%
5.24%
10.94%
7.69%
7.76%
9.72%
9.38%
6.51%
8.47%
Sig
from
zero?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Bm
[Ib/mph]
0.165
1.105
-2.070
-2.065
-6.123
-1.979
1.153
-3.480
-1.149
Std err
497.00%
41.42%
-177.70%
-122.70%
-47.40%
-127.80%
119.90%
-63.15%
-238.00%
Sig
from
zero?
No
Yes
No
No
No
No
No
No
No
D
[Ib/mph2]
0.143
0.127
0.233
0.237
0.291
0.244
0.174
0.248
0.208
%
Std
err
9.64
%
5.86
%
25.8
7%
17.9
9%
16.5
5%
17.3
8%
12.2
7%
14.1
1%
21.0
4%
Sig
from
zero?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
In MM6, the elimination of Bm shows confident and stable estimates of^4m and/), with
lower relative standard errors. This indicates that the road load curve is best described by just
Am andD.
3-12
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
Table 3-3 - Mixed Model MM6 Shows the Most Confident Estimates of A and D.
Date
5-Aug-09
6-Aug-09
1-Sep-09
2-Sep-09
3-Sep-09
18-Sep-09
23-Sep-09
24-Sep-09
25-Sep-09
Truck configuration
FL60_N/A_full
FL60_N/A_full
lnt'l_flatbed_full
lnt'l_flatbed_full
lnt'l_flatbed_full
lnt'l_flatbed_half
lnt'l_flatbed_empty
lnt'l_box_full
lnt'l_box_full
Am[N]
693.9
676.8
2060.3
2030.6
2093.6
1539.8
1076.2
2119.1
2136.5
Am [Ib]
156.0
152.2
463.2
456.5
470.7
346.2
242.0
476.4
480.3
% Std error
3.81%
2.63%
4.85%
3.71%
3.89%
3.92%
4.53%
3.87%
4.12%
D [N/(m/s)2]
3.24
3.23
4.45
4.51
4.25
4.71
4.27
4.32
4.23
D [Ib/mph2]
0.145
0.145
0.200
0.203
0.191
0.212
0.192
0.194
0.190
% Std error
2.05%
1.13%
6.08%
4.59%
5.55%
4.09%
2.39%
4.06%
4.88%
Compared to the MM4, MM6 produces more confident mean coefficient values. Also,
for the same configurations, the MM6 shows better day-to-day variability, confirming that the
coastdown procedure is repeatable from one day to the next. Often, the MM6 model is used to
simplify the road load versus speed curve through rolling resistance and aerodynamic drag
coefficients. The EPA MOVES heavy-duty inventory model and the CRC E-55/59 chassis
dynamometer emissions test program are two examples of this. In general, the equation
implemented during a coastdown is:
Equation 11
dV
—
1
-
Therefore,
Equation 12
// =
A , D
—^- and CD =
Mg
2pA
Equation 13
Equation 11 and Equation 12 assume that the rolling resistance coefficient // is wholly
contained in the Am coefficient and the drag coefficient Cd is wholly contained in the D
coefficient. The equations also imply that any values of Bm and Cm that would be used in the
other mixed models are mechanical drag forces, other than rolling resistance, that are dependent
on vehicle speed. To check the reasonability of our results and feasibility of using our
3-13
-------
Draft Regulatory Impact Analysis
coefficients to accurately determine // and Cd, we can compare our results to realistic values of
rolling resistance and drag coefficients.
Rolling Resistance Coefficient
For the International truck, we recorded the tire model and obtained different laboratory
results of tire rolling resistance coefficients. These values were determined through the SAE
J1269 standard. This standard does not contain a provision that lets a laboratory result be
corrected against a reference laboratory result. As a result, each laboratory has its own bias for
any given tire. When we weighed the truck, we recorded the weight measured over each axle:
steer, drive, and trailer. Since we had no more than one tire model on any one axle, we can
weight-average the laboratory rolling resistance coefficients to estimate the truck's overall
rolling resistance coefficient.
Equation 14
^
M
dnve
Figure 3-1 below compares our coastdown rolling resistance results with those from three
different tire labs. We are not naming the tire models or the laboratories to protect confidential
business information. The dimensionless rolling resistance coefficient is multiplied by 1000 for
convenience (resulting "unit" is often referred to as kg/metric ton).
Figure 3-1 - Coastdown-Determined and Independent Lab Rolling Resistance Coefficients Match Reasonably
Well.
I6
•- 5
u 3
O 4
8
I3
£
-2
*Coastdown RR
• Lab A
ALabB
• LabC
D 3 Lab avg
"§
e
"§
e
"§
e
5-Aug-09 6-Aug-09 1-Sep-09 2-Sep-09 3-Sep-09 18-Sep-09 23-Sep-09 24-Sep-09 25-Sep-09
There are only three different labs, with four unique weightings (flatbed full, flatbed half,
flatbed empty, and box full) for each lab. Lab results were only available for the tires used on
the International truck. Our coastdown results show reliable day-to-day repeatability for the
same truck configuration (Sep 1-3, Sep 24-25). Also, when we reduced the weight on the flatbed
3-14
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
trailer, we found that our coastdowns produced a higher theoretical tire rolling resistance. This is
most likely due to the fact that reducing weight from full payload increases the relative weight
over the drive axle. Since the tires on the drive axle have a higher rolling resistance coefficient
(inverse relation with grip for a given tire material and surface), the overall rolling resistance
coefficient increased. This is confirmed by the lab tests, which showed higher rolling resistance
coefficients for the drive and steer axles tire models. Our coastdown results do, however, show a
larger increase in coefficient due to complete payload removal compared to the lab results.
The agencies are not proposing to use coastdown testing to determine the tire rolling
resistance. The proposed tire test procedures are discussed in Section 3.3.
Drag Coefficient
We estimated frontal area of the International truck to be 99 ft2 (9.2 m2) by measuring the
various dimensions of the tractor cab and other equipment such as exterior mirrors and tires. We
used this value as a placeholder estimate for the FL60 vehicle also. Using these frontal area
estimates and Equation 13, Figure 3-2 shows our coastdown-estimated drag coefficients for each
date and truck configuration.
Figure 3-2 - Drag Coefficient Calculated from D from Mixed Model
1.2
1.0
0.8
0.6
0.4
0.2
0.0
f-H
*—r
5-Aug-09
6-Aug-09
1-Sep-09
2-Sep-09
3-Sep-09
18-Sep-09
23-Sep-09
24-Sep-09 25-Sep-09
Unlike rolling resistance, we do not expect our drag coefficient to change with payload
removal because the physical configuration of the tractor-trailer is not significantly altered,
which is reflected in Figure 3-2. Also, while we are using a frontal area of 9.2 m2 specific to the
International tractor, a uniform frontal area, such as an average box trailer frontal area or typical
tractor frontal area, may be used for all trucks of a certain class when determining drag
coefficient as an input to the compliance model.
3-15
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Draft Regulatory Impact Analysis
3.2.2.2 Wind Tunnel Testing
A wind tunnel provides a stable environment yielding a more repeatable test than
coastdown. This allows the manufacturer to run multiple baseline vehicle tests and explore
configuration modifications for nearly the same effort (e.g., time and cost) as conducting the
coastdown procedure. In addition, wind tunnels provide testers with the ability to yaw the
vehicle at positive and negative angles relative to the original centerline of the vehicle to
accurately capture the influence of non-uniform wind direction on the Cd (e.g., wind averaged
Cd).
However, there are challenges with the use of wind tunnels in a regulatory program that
would need to be addressed in order for manufacturers to use this method. There are several
different configurations and types of wind tunnels. There are wind tunnels that use forced air
(fan upstream pushing air through the wind tunnel) versus suction (fan downstream and pulling
air through the wind tunnel). There are wind tunnels with open or semi-open jet, closed jet, and
slotted or adaptive wall test sections. There are wind tunnels with static floors versus moving
floors or suction that compensate for the boundary layer of air that builds up at the ground level.
Finally, there are full scale wind tunnels (e.g., dimensions as large as 80 feet times 120 feet in the
test section) that can accommodate a full-size vehicle or clay model versus reduced scale wind
tunnels (e.g., dimensions as small as 3 feet by 4.5 feet) that require the vehicle to be scaled down
in model form. In addition, regardless of wind tunnel type there are several factors that would
need to be minimized or addressed by applying correction factors to maintain flow quality
including but not limited to ground boundary layer thickness and location; flow uniformity,
angularity and fluctuation; turbulence and wall interference, and environmental conditions (e.g.,
temperature, humidity, air/fluid density) in the tunnel.
As a result of the wind tunnel testing issues and configuration complexities, it would be
difficult to develop a new, uniform wind tunnel testing standard for this rulemaking. Therefore,
the agencies propose to use the established SAE standards for wind tunnel testing (such as SAE
J1252) and recommended practices, with some modifications and exceptions, for aerodynamic
assessment.
3.2.2.3 Computational Fluid Dynamics
Computational Fluid Dynamics, or CFD, capitalizes on today's computing power by
modeling a full size vehicle and simulating the flows around this model to examine the fluid
dynamic properties, in a virtual environment. CFD tools are used to solve either the Navier-
Stokes equations that relate the physical law of conservation of momentum to the flow
relationship around a body in motion or a static body with fluid in motion around it, or the
Boltzman equation that examines fluid mechanics and determines the characteristics of discreet,
individual particles within a fluid and relates this behavior to the overall dynamics and behavior
of the fluid. CFD analysis involves several steps: defining the model structure or geometry
based on provided specifications to define the basic model shape; applying a closed surface
around the structure to define the external model shape (wrapping or surface meshing); dividing
the control volume, including the model and the surrounding environment, up into smaller,
discreet shapes (gridding); defining the flow conditions in and out of the control volume and the
3-16
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
flow relationships within the grid (including eddies and turbulence); and solving the flow
equations based on the prescribed flow conditions and relationships.
This approach can be beneficial to manufacturers since they can rapidly prototype (e.g.,
design, research, and model) an entire vehicle without investing in material costs; they can
modify and investigate changes easily; and the data files can be re-used and shared within the
company or with corporate partners.
As with the two aerodynamic assessment methods mentioned above, CFD has challenges
that must be addressed. Although it can save on material cost, it can be time consuming
(manpower cost) and requires significant computing power depending on the model detail
(information technology costs). As described above, a considerable amount of time goes into
defining the shape, meshing or gridding the shape and the environment, and solving all of the
associated flow equations. Meshes/grids in CFD can contain anywhere from 1 million to 100
million individual cells depending on the modeler's criteria. Consequently, run times needed to
solve all of the flow relationships can be extremely long.
The accuracy of the outputs from CFD analysis can be highly dependent on the inputs.
The CFD modeler decides what method to use for wrapping, how fine the mesh cell and grid size
should be, and the physical and flow relationships within the environment. A balance must be
achieved between the number of cells, which defines how fine the mesh is, and the
computational times for a result (i.e., solution-time-efficiency). All of these decisions affect the
results of the CFD aerodynamic assessment.
In addition, CFD software tools have difficulty solving for complex turbulent flows and
the spatial interaction that occurs in real-world aerodynamics. This source can lead to large
errors between the actual and predicted aerodynamic characteristics. Therefore, care must be
taken to ensure that the various turbulent flows and ground/wall interference affects are
accounted for.
As with any software tool, the CFD software marketplace is vast and ever-evolving at an
astonishing pace. There are commercially-available CFD software tools and publicly-available
customized CFD software tools used by academia and government agencies. Any attempt to
require one particular CFD software tool in a rulemaking would nearly guarantee its
obsolescence by the time the rule was published. In addition, no two CFD software tools are
alike and there are currently no established SAE standards or recommended practices, that we
are aware of, governing the use of CFD. As a result, it is difficult propose a particular CFD
software tool or approach in a regulatory arena.
Much of the recent research has examined the correlation of CFD to experimental results
and to determine the sensitivity of the results to certain aspects of CFD (e.g., varying cell size
and shape, grid size and meshing technique). This research can aid in defining boundaries for
the use of CFD in aerodynamic assessment. In addition, the available research has demonstrated
correlation of CFD predictions within one to five percent of experimental results. 8 Thus, CFD
does have some ability to accurately model aerodynamic assessments, if conditions for
performing the analysis are appropriately defined.
3-17
-------
Draft Regulatory Impact Analysis
To address these considerations, the agencies propose a minimum set of criteria
applicable to using CFD for aerodynamic assessment (should a manufacturer choose to use this
means of aerodynamic assessment). This will allow the use of CFD and the design freedom that
it offers while ensuring that, regardless of the decisions made during the process, the CFD
aerodynamic assessment accurately simulates real-world aerodynamics.
3.2.2.4 Aerodynamic Assessment Proposal
The agencies are proposing that the coefficient of drag assessment be a product of test
data and modeling using good engineering judgment. This is a similar approach that EPA has
provided as an option in testing light-duty vehicles where the manufacturers supply
representative road load forces for the vehicle.9
The agencies are also interested in developing an acceptance demonstration process for
aerodynamic testing in the final rulemaking. As part of the process, the manufacturer would
have to demonstrate that the methodology used for aerodynamic assessment is acceptable prior
to using it for aerodynamic assessment. In addition to the acceptance demonstration, alternative
methods would also require correlation testing to the coastdown procedure using a reference
vehicle. This process would provide confidence in the use of the alternative method once this
rule is implemented. We are requesting comment on the proposed requirements for each allowed
method, standards and practices that should be used and any unique criteria that we are
proposing.
In addition, EPA and NHTSA recognize that wind conditions have a greater impact on
real world CO2 emissions and fuel consumption of heavy-duty trucks than occur with light-duty
vehicles. As stated in the NAS report10, the wind average drag coefficient is about 15 percent
higher than the zero degree coefficient of drag (Cd). The large ratio of the side area of a
combination tractor and trailer to the frontal area illustrates that winds will have a significant
impact on the drag. One disadvantage of the agencies' proposed approach to aerodynamic
assessment is that the test methods have varying degrees of ability to assess wind conditions.
Wind tunnels are currently the only demonstrated tool to accurately assess the influence of wind
speed and direction on a truck's aerodynamic performance. Both the coastdown tests and
computational fluid dynamics modeling have limited ability in assessing yaw conditions. To
address this issue, the agencies are proposing to use coefficient of drag values which represent
zero yaw (i.e., representing wind from directly in front of the vehicle, not from the side). The
agencies recognize that the results of using the zero yaw approach will produce fuel consumption
results in the regulatory program which are slightly lower than in-use but we believe this
approach is appropriate since not all manufacturers will use wind tunnels for the aerodynamic
assessment.
NHTSA and EPA are proposing that manufacturers take the aerodynamic test result from
a truck and determine the appropriate bin (e.g., Classic, Conventional, SmartWay, etc.), as
defined in Table 3-4. The agencies are proposing aerodynamic technology categories which
divide the wide spectrum of tractor aerodynamics into five categories. The first category,
"Classic," represents tractor bodies which prioritize appearance or special duty capabilities over
aerodynamics. The Classic trucks incorporate few, if any, aerodynamic features and may have
several which detract from aerodynamics, such as bug deflectors, custom sunshades, b-pillar
3-18
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
exhaust stacks, and others. The second category for aerodynamics is the "Conventional" tractor
body. The agencies consider Conventional tractors to be the average new tractor today which
capitalizes on a generally aerodynamic shape and avoids classic features which increase drag.
Tractors within the "SmartWay" category build on Conventional tractors with added components
to reduce drag in the most significant areas on the tractor, such as fully enclosed roof fairings,
side extending gap reducers, fuel tank fairings, and streamlined grill/hood/mirrors/bumpers. The
"Advanced SmartWay" aerodynamic category builds upon the SmartWay tractor body with
additional aerodynamic treatments such as underbody airflow treatment, down exhaust, and
lowered ride height. "Advanced SmartWay II" tractors incorporate advanced technologies which
are currently in the prototype stage of development, such as advanced gap reduction, rearview
cameras to replace mirrors, wheel system streamlining, and advanced body designs.
Under this proposal, the manufacturer would then input into GEM the Cd value specified
for each bin as also defined in Table 3-4. For example, if a manufacturer tests a Class 8 sleeper
cab high roof tractor with features which are similar to a SmartWay tractor and the test produces
a Cd value of 0.59, then the manufacturer would assign this tractor to the Class 8 Sleeper Cab
High Roof SmartWay bin. The manufacturer would then use the Cd value of 0.60 as the input to
GEM. The agencies are proposing the aerodynamic bin approach to address the variability in the
proposed testing methods.
Table 3-4: Aerodynamic Input Definitions to GEM
Class 7
Day Cab
Low/Mid
Roof
High
Roof
Class 8
Day Cab
Low/Mid
Roof
High
Roof
Sleeper Cab
Low
Roof
Mid
Roof
High
Roof
Aerodynamics Test Results (Cd)
Classic
Conventional
SmartWay
Advanced SmartWay
Advanced SmartWay
II
>0.83
0.78-0.82
0.73-0.77
0.68-0.72
<0.67
>0.73
0.63-
0.72
0.58-
0.62
0.53-
0.57
<0.52
>0.83
0.78-0.82
0.73-0.77
0.68-0.72
<0.67
>0.73
0.63-
0.72
0.58-
0.62
0.53-
0.57
<0.52
>0.83
0.78-
0.82
0.73-
0.77
0.68-
0.72
<0.67
>0.78
0.73-
0.77
0.68-
0.72
0.63-
0.67
<0.62
>0.73
0.63-
0.72
0.58-
0.62
0.53-
0.57
<0.52
Aerodynamic Input to GEM (Cd)
Frontal Area (m2)
Classic
Conventional
SmartWay
Advanced SmartWay
Advanced SmartWay
II
6.0
0.85
0.80
0.75
0.70
0.65
9.8
0.75
0.65
0.60
0.55
0.50
6.0
0.85
0.80
0.75
0.70
0.65
9.8
0.75
0.65
0.60
0.55
0.50
6.0
0.85
0.80
0.75
0.70
0.65
7.7
0.80
0.75
0.70
0.65
0.60
9.8
0.75
0.68
0.60
0.55
0.50
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Draft Regulatory Impact Analysis
Coefficient of drag (Cd) and frontal area of the tractor-trailer combination go hand-in-
hand to determine the force required to overcome aerodynamic drag. As explained above, the
agencies are proposing that the Cd value is one of the GEM inputs which will be derived by the
manufacturer. However, the agencies are proposing to specify the truck's frontal area for each
regulatory subcategory (i.e. each of the seven subcategories which are proposed). The frontal
area of a high roof tractor pulling a box trailer will be determined primarily by the box trailer's
dimensions and the ground clearance of the tractor. The frontal area of low and mid roof tractors
will be determined by the tractor itself. An alternate approach to the proposed frontal area
specification is to create the aerodynamic input table (as discussed in Table 3-4) with values that
represent the Cd multiplied by the frontal area. This approach will provide the same
aerodynamic load, but it will not allow the comparison of aerodynamic efficiency across
regulatory subcategories that can be done with the Cd values alone.
The agencies recognize that wind conditions have a greater impact on real world GHG
emissions from heavy-duty trucks than occur with light-duty vehicles. The ratio of the side area
of a combination tractor and trailer to the frontal area illustrates that winds will have a significant
impact on the drag. A disadvantage of the proposed approach to aerodynamic assessment is that
the test methods have varying degrees of ability to assess wind conditions. Wind tunnels are
currently the only tool which has demonstrated the ability to accurately assess the influence of
wind speed and direction on a truck's aerodynamic performance. Therefore, we are proposing to
use coefficient of drag values which represent zero yaw.
3.3 Tire Rolling Resistance
EPA is proposing that the ISO 28580 test method be used to determine rolling resistance
and the coefficient of rolling resistance. A copy of the test method can be obtained through the
American National Standards Institute
(http://webstore.ansi.org/RecordDetail.aspx? sku=ISO+28580%3 a2009).
3.3.1 Reason for Using ISO 28580
The EPA SmartWay Partnership Program started to identify equipment and feature
requirements for SmartWay-designated Class 8 over-the-road tractors and trailers in 2006. In
order to develop a tire rolling resistance specification for SmartW ay-designated commercial
trucks, EPA researched different test methods used to evaluate tire rolling resistance, reviewing
data and information from tire manufacturers, testing laboratories, the State of California, the
Department of Transportation, truck manufacturers, and various technical organizations. After
assessing this information, EPA determined that its SmartWay program would use the SAE
J126911 tire rolling resistance method until the ISO 2858012 method (at that time under
development) was finalized, at which time the Agency would consider moving to this method for
its SmartWay program.
During this same time period, the National Highway Traffic Safety Administration
(NHTSA) conducted an evaluation of passenger vehicle tire rolling resistance test methods and
their variability13. Five different laboratory test methods at two separate labs were evaluated.
The NHTSA study focused on passenger tires; however, three of the four test methods evaluated
can be used for medium-duty and heavy-duty truck tires. The methods evaluated were SAE
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
J1269, SAE J245214 (not applicable for medium-duty or heavy-duty truck tires), ISO 1816415
and ISO 28580. The NHTSA study showed significant lab to lab variability between the labs
used. The variability was not consistent between tests or types of tire within the same test. The
study concluded that a method to account for this variability is necessary if the rolling resistance
value of tires is to be compared (NHTSA, 2009). Because of laboratory variability, NHTSA
recommended that the use of ISO 28580 is preferred over the other test methods referenced.
The reason that ISO 28580 is preferred is that the test involves a laboratory alignment is
between a "reference laboratory" and a "candidate laboratory." The ISO technical committee
involved in developing this test method also has the responsibility for determining the laboratory
that will serve as the reference laboratory. The reference laboratory will make available an
alignment tire that can be purchased by candidate laboratories. The candidate laboratory shall
identify its reference machine. However, at this time, the reference laboratory and alignment
tires have not been identified.
3.3.2 Measurement Method and Results
The ISO 28580 test method includes a specific methodology for "light truck, commercial
truck and bus" tires, and it has 4 measurement methods, force, torque, deceleration, and power,
all of which appear to be suitable for use.
The results of the ISO 28580 test are intended for use in vehicle simulation modeling,
such as the model used to assess the effects of various technology options for national
greenhouse gas and fuel economy requirements for commercial trucks (see chapter 4). The
results are usually expressed as a rolling resistance coefficient and measured as kilogram per
metric ton (kg/metric ton) or as dimensionless units. (1 kg/metric ton is the same as the
dimensionless unit 0.001) The results are corrected for ambient temperature drum surface and
drum diameter as specified in the test method.
3.3.3 Sample Size
The rolling resistance of tires within the same model and construction are expected to be
relatively uniform. In the study conducted by NHTSA, only one individual tire had a rolling
resistance value that was significantly different from the other tires of the same model. This
means that only one tire within a model needs to be tested to obtain a representative value of
rolling resistance for the model. The effect of test-to-test variability can be further reduced by
conducting three replicate tests and using the average as the value for the rolling resistance
coefficient. Tire models available in multiple diameters may have different values of rolling
resistance for each diameter because larger diameter tires produce lower rolling resistance than
smaller diameters under the same load and inflation conditions. If the size range within a tire
model becomes large enough that a given tire size is no longer "substantially similar" in rolling
resistance performance to all other tire sizes of that model, then good engineering judgment
should be exercised as to whether the differently-sized tire shall be treated, for testing and
vehicle simulation purposes, as a distinct tire model. For Class 8 tractors that typically use tires
that fit on 22.5" or 24.5" wheels, this situation might occur with 17.5" tires, more commonly
used on moving vans and other applications that require a low floor.
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Draft Regulatory Impact Analysis
3.4 Drive Cycle
Drive cycles have a significant impact on the GHG emissions from a truck and how
technologies are assessed. Every truck has a different drive cycle in-use. Therefore, it is very
challenging to develop a uniform drive cycle which accurately assesses GHG improvements
from technologies relative to their performance in the real world.
The drive cycle attributes that impact a vehicle's performance include average speed,
maximum speed, acceleration rates, deceleration rates, number of stops, road grade, and idling
time. Average and maximum speeds are the attributes which have the greatest impact on
aerodynamic technologies. Vehicle speed also impacts the effect of low rolling resistance tires.
The effectiveness of extended idle reduction measures is determined by the amount of time spent
idling. Lastly, hybrid technologies demonstrate the greatest improvement on cycles which
include a significant amount of stop-and-go driving due to the opportunities to recover braking
energy. In addition, the amount of power take-off operation will impact the effectiveness of
some vocational hybrid applications.
The ideal drive cycle for a line-haul truck would account for significant amount of time
spent cruising at high speeds. A pickup and delivery truck would contain a combination of urban
driving, some number of stops, and limited highway driving. If EPA proposes an ill-suited drive
cycle for a regulatory subcategory, it may drive technologies where they may not see the in-use
benefits. For example, requiring all trucks to use a constant speed highway drive cycle will drive
significant aerodynamic improvements. However, in the real world a pickup and delivery truck
may spend too little time on the highway to realize the benefits of aerodynamic enhancements.
In addition, the extra weight of the aerodynamic fairings will actually penalize the GHG
performance of that truck in urban driving and may reduce its freight carrying capability.
3.4.1 Drive Cycles Considered
The agencies carefully considered which drive cycles are appropriate for the different
proposed regulatory subcategories. We considered several drive cycles in the development of
the proposal including EPA's MOVES model; the Light-Duty FTP75 and HWFEC; Heavy-Duty
UDDS; World Wide Transient Vehicle Cycle (WTVC); Highway Line Haul; Hybrid Truck User
Forum (HTUF) cycles; and California ARB's Heavy-Heavy-Duty Truck 5 Mode Cycle.
MOVES Medium-Duty and Heavy-Duty schedules were developed based on three
studies. Eastern Research Group (ERG) instrumented 150 medium and heavy-duty vehicles,
Battelle instrumented 120 vehicles instrumented with GPS, and Faucett instrumented 30 trucks
to characterize their in-use operation.16 ERG then segregated the driving into freeway and non-
freeway driving for medium and heavy-duty vehicles, and then further stratified vehicles trips
according the predefined ranges of average speed covering the range of vehicle operation.
Driving schedules were then developed for each speed bin by creating combinations of idle-to-
idle "microtrips" until the representative target metrics were achieved. The schedules developed
by ERG are not contiguous schedules which would be run on a chassis dynamometer, but are
made up of non-continguous "snippets" of driving meant to represent target distributions. This
gives MOVES the versatility to handle smaller scale inventories, such as intersections or sections
of interstate highway, independently.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
The FTP75 and HWFEC drive cycles are used extensively for Light-Duty emissions and
CAFE programs. Our assessment is that these cycles are not appropriate for HD trucks for two
primary reasons. First, the FTP has 24 accelerations during the cycle which are too steep for a
Class 8 combination tractor to follow. Second, the maximum speed is 60 mph during the
HWFEC, while the national average truck highway speed is 65 mph.
The Heavy-Duty Urban Dynamometer Driving Cycle was developed to determine the
Heavy-Duty Engine FTP cycle. The cycle was developed from CAPE-21 survey data which
included information from 44 trucks and 3 buses in Los Angeles and 44 trucks and 4 buses in
New York in 1977. The cycle was computer generated and weighted to represent New York
non-freeway (254 sec), Los Angeles non-freeway (285 sec), Los Angeles freeway (267 sec),
New York non-freeway (254 sec) to produce a nearly 50/50 weighting of highway cruise and
urban transient. We believe this cycle is not appropriate for our program for several reasons.
The maximum speed on the UDDS is 58 mph which is low relative to the truck speed limits in
effect today. The 50/50 weighting of cruise to transient is too low for combination tractors and
too high for vocational vehicles and the single cycle does not provide flexibility to change the
weightings. Lastly, the acceleration rates are low for today's higher power trucks.
The World Harmonized WTVC was developed by the UN ECE GRPE group. It represents
urban, rural, and motorway operation. The cycle was developed based on data from 20 straight
trucks, 18 combination tractors, and 11 buses total from Australia, Europe, Japan, and US. EPA
has a desire to harmonize internationally, however, we believe this single cycle does not
optimally cover the different types of truck operation in the United States and does not provide
the flexibility to vary the weightings of a single cycle.
The Highway Line Haul schedule was created by Southwest Research Institute, using input
from a group of stakeholders, including EPA, Northeastern States for Coordinated Air Use
Management (NESCAUM), several truck and engine manufacturers, state organizations, and
others, for a NESCAUM heavy truck fuel efficiency modeling and simulation project. The cycle
is 103 miles long and incorporates grade and altitude. This cycle is a good representation of line
haul operation. However, the grade and altitude changes cannot be incorporated into a chassis
dynamometer or track test. The cycle is also too long for a typical chassis dynamometer test.
The Calstart-Weststart Hybrid Truck Users Forum is developing cycles to match the
characteristics of trucks applications which are expected to be first to market for hybrids. The
cycles include the Manhattan Bus Cycle, Orange County Bus Cycle, Class 4 Parcel Delivery,
Class 6 Parcel Delivery, Combined International Local and Commuter Cycle (CILCC),
Neighborhood Refuse, Utility Service, and Intermodal Drayage cycles. The cycles are very
application-specific and appropriately evaluate each vocation. However, the use of these type of
application specific cycles in a regulatory scheme will lead to a proliferation of cycles for every
application, an outcome that is not desirable.
The ARE 5 Mode cycle was developed from data gathered by the University of California
Riverside in collaboration with California ARE from 270 1993 through 2001 MY trucks and
over 1 million miles of activity. The cycles were developed to reflect typical in-use behavior as
demonstrated from the data collected. The four modes (idle, creep, transient, and cruise) were
determined as distinct operating patterns, which then led to the four drive schedules. The cycle
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Draft Regulatory Impact Analysis
is well accepted in the heavy-duty industry. It was used in the CRC E55/59 Study which is the
largest HD chassis dynamometer study to date and used in MOVES and EMFAC to determine
emission rate inputs; the EPA biodiesel study which used engine dynamometer schedules created
from ARB cruise cycle; the HEI ACES Study: WVU developed engine cycles from ARB 4-
mode chassis cycles; CE/CERT test; and by WVU to predict fuel efficiency performance on any
drive cycle from ARB 5 mode results. The modal approach to the cycles provides flexibility in
cycle weightings to accommodate a variety of truck applications. A downside of the cycle is that
it was developed from truck activity in California only.
3.4.2 Proposed Drive Cycles
The drive cycle we are proposing is a modified version of the California Air Resource
Board (CARB) Heavy Heavy-Duty Truck 5 Mode Cycle. We are proposing the use of the
Transient mode, as defined by CARB. The cycle is 668 seconds long and travels 2.84 miles.
The cycle contains 5 stops and contains 112 seconds idling. The maximum speed of the cycle is
47.5 mph with an average speed of 15.3 mph.
We are also proposing to alter the High Speed Cruise and Low Speed Cruise modes to
reflect only constant speed cycles at 65 mph and 55 mph respectively. Based on input from
trucking fleets and truck manufacturers, we believe the latter is representative of in-use
operation, wherein truck drivers use cruise control whenever the possible during periods of
sustained higher speed driving.
3.4.3 Weightings of Each Cycle per Regulatory Subcategory
As mentioned above, the advantage of using a modal approach to drive cycles is that the
standardized modes can be weighted differently to reflect the difference in operating conditions
of various truck applications.
The development of the Class 8 sleeper cab cycle weightings is based on studies
developed to characterize the operation of line haul trucks. The EPA MOVES model, a study
conducted by University of California Riverside, an estimation of commercial truck idling
conducted by Argonne National Lab, and a tire test on line haul trucks conducted by Oak Ridge
National Lab were used in the weighting analysis.
The distribution of vehicle miles travelled (VMT) among different speed bins was
developed for the EPA MOVES model from analysis of the Federal Highway Administration
data. The data is based on highway vehicle monitoring data from FHWA used to develop the
distribution of VMT among road types from 1999. The information on speed distributions on the
different type of roads at different times of day came from traffic modeling of urban locations
and chase car data in rural California. This data was used to characterize the fraction of VMT
spent in high speed cruise versus transient operation.
The University of California Riverside and California Air Resource Board evaluated
engine control module data from 270 trucks which travelled over one million miles to develop
the heavy-duty diesel truck activity report in 2006.1? The study found that line haul trucks spend
approximately 50% of the time cruising at speeds greater than 45 mph, 10% of time in transient
stop-and-go driving, and 40% in extended idle operation. After removing the idle portion to
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
establish weightings of only the motive operation, the breakdown looks like 82% of the time
cruising at speeds greater than 45 mph and 18% in transient operation.
Argonne National Lab estimated the percentage of fuel consumed while idling for various
combinations of trucks, such as sleeper cabs.18 The estimation is based on FHWA's Highway
Statistics and the Census Bureau's Vehicle In-Use Survey (VIUS). The study found that Class 8
sleeper cabs use an average of 6.8% of their fuel idling.
Oak Ridge National Laboratory evaluated the fuel efficiency effect of tires on Class 8
heavy trucks.19 The study collected fleet data related to real-world highway environments over a
period of two years. The fleet consisted of six trucks which operate widely across the United
States. In the Transportation Energy Data Book (2009)20 Table 5.11 was analyzed and found on
average that the line haul trucks spent 5% of the miles at speeds less than 50 mph, 17% between
50 and 60 mph, and 78% of the time at speeds greater than 60 mph.
Table 3-5: Combination Tractor Drive Cycle Weighting and Table 3-6: Vocational
Vehicle Drive Cycle Weighting summarize the studies and the agencies' proposal for drive cycle
weightings.
Table 3-5: Combination Tractor Drive Cycle Weighting
> 60 mph
50-60 mph
< 50 mph
MOVES
All
64%
17%
19%
Restricted
Access
86%
9%
5%
UCR
Short
Haul
47%
> 45 mph
53%
Long
Haul
81%
> 45 mph
5%
Proposal
Sleeper Cab
Proposal
86%
65 mph Cruise
9%
55 mph Cruise
5%
Transient
Day Cab
Proposal
64%
65 mph
Cruise
17%
55 mph
Cruise
19%
Transient
Table 3-6: Vocational Vehicle Drive Cycle Weighting
> 60 mph
50-60 mph
< 50 mph
MOVES
Single Unit
37%
21%
42%
UCR
Medium-Duty
16%
> 45 mph
84%
Proposal
37%
65 mph Cruise
21%
55 mph Cruise
42%
Transient
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Draft Regulatory Impact Analysis
The proposed drive cycle weightings for each regulatory category are included in Table
3-7: Drive Cycle Mode Weightings.
Table 3-7: Drive Cycle Mode Weightings
Transient
55 mph Cruise
65 mph Cruise
VOCATIONAL
VEHICLES
42%
21%
37%
DAY CABS
19%
17%
64%
SLEEPER CABS
5%
9%
86%
3.5 Tare Weights and Payload
The total weight of a truck is the combination of the truck's tare weight, a trailer's tare
weight (if applicable), and the payload. The total weight of a truck is important because it in part
determines the impact of technologies, such as rolling resistance, on GHG emissions and fuel
consumptions. As the HD program is proposed, it is important that the agencies define weights
which are representative of the fleet while recognizing that the proposed weights are not
representative of a specific vehicle. The sections below describe the agencies' approach to
defining each of these weights.
3.5.1
Truck Tare Weights
The tare weight of a truck will vary depending on many factors, including the choices
made by the manufacturer in designing the truck (such as the use of lightweight materials, the
cab configuration (such as day or sleeper cab), whether it has aerodynamic fairing (such as a roof
fairing), and the specific options on the truck.
The proposed Class 8 combination tractor tare weights were developed based on the
weights of actual tractors tested in the EPA coastdown program. The empty weight of the Class
8 sleeper cabs with a high roof tested ranged between 19,000 and 20,260 pounds. The empty
weight of the Class 8 day cab with a high roof tested was 17,840 pounds. The agencies derived
the tare weight of the Class 7 day cabs based on the guidance of truck manufacturer. The
agencies then assumed that a roof fairing weighs approximately 500 pounds. Based on this, the
agencies are proposing the tractor tare weights as shown in Table 3-8.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
Table 3-8: Tractor Tare Weights
MODEL TYPE
Regulatory
Subcategory
Tractor Tare
Weight (Ibs)
CLASS 8
Sleeper Cab
High Roof
19,000
CLASS 8
Sleeper Cab
Mid Roof
18,750
CLASS 8
Sleeper Cab
Low Roof
18,500
CLASS 8
Day Cab
High Roof
17,500
CLASS 8
Day Cab
Low Roof
17,000
CLASS 7
Day Cab
High Roof
11,500
CLASS 7
Day Cab
Low Roof
11,000
The agencies developed the empty tare weights of the vocational vehicles based on the
91
EDF report on GHG management for Medium-Duty Fleets. The EDF report found that the
average tare weight of a Class 4 truck is 10,343 pounds, of a Class 6 trucks is 13,942 pounds,
and a Class 8 as 28,979 pounds. The agencies are proposing the following tare weights:
• Light Heavy (Class 2b-5) = 10,300 pounds
• Medium Heavy (Class 6-7) = 13,950 pounds
• Heavy Heavy (Class 8) = 29,000 pounds
3.5.2 Trailer Tare Weights
The proposed trailer tare weights are based on measurements conducted during EPA's
coastdown testing and information gathered by ICF in the cost report to EPA.
A typical 53 foot box (or van) trailer has an empty weight ranging between 13,500 and
14,000 pounds per ICF's findings. The box trailer tested by EPA in the coastdown testing
weighed 13,660 pounds. Therefore, the agencies are proposing to define the empty box trailer
weight as 13,500 pounds.
A typical flatbed trailer weighs between 9,760 and 10,760 per the survey conducted by
ICF. EPA's coastdown work utilized a flatbed trailer which weighed 10,480 pounds. Based on
this, the agencies are proposing a defined flatbed trailer weight of 10,500 pounds.
Lastly, a tanker trailer weight typically ranges between 9,010 and 10,500 pounds based
on ICF findings. The tanker trailer used in the coastdown testing weighed 9,840 pounds. The
agencies are proposing an empty tanker trailer weight of 10,000 pounds.
3.5.3
Payload
The amount of payload by weight that a tractor can carry depends on the class (or
GVWR) of the vehicle. For example, a typical Class 7 tractor can carry fewer tons of payload
than a Class 8 tractor. Payload impacts both the overall test weight of the truck and is used to
assess the "per ton-mile" fuel consumption and GHG emissions. The "tons" represent the
payload measured in tons.
M. J. Bradley analyzed the Truck Inventory and Use Survey and found that approximately
9 percent of combination tractor miles travelled empty, 61 percent are "cubed-out" (the trailer is
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Draft Regulatory Impact Analysis
full before the weight limit is reached), and 30 percent are "weighed out" (operating weight
equal 80,000 pounds which is the gross vehicle weight limit on the Federal Interstate Highway
System or greater than 80,000 pounds for vehicles traveling on roads outside of the interstate
system).23 The Federal Highway Administration developed Truck Payload Equivalent Factors
to inform the development of highway system strategies using Vehicle Inventory and Use Survey
(VIUS) and Vehicle Travel Information System (VTRIS) data. Their results, as shown in Table
3-9, found that the average payload of a Class 8 truck ranged from 29,628 to 40,243 pounds,
depending on the average distance travelled per day.24 The same results found that Class 7
trucks carried between 18,674 and 34,210 pounds of payload also depending on average distance
travelled per day.
Table 3-9: National Average Payload (Ibs.) per Distance Travelled and Gross Vehicle Weight Group (VIUS)25
< 50 miles
51 tolOO miles
101 to 200
miles
201 to 500
miles
> 500 mile
Average
CLASS 3
3,706
3,585
4,189
4,273
3,216
3,794
CLASS 4
4,550
4,913
6,628
7,029
8,052
6,234
CLASS 5
8,023
6,436
8,491
6,360
6,545
7,171
CLASS 6
10,310
10,628
12,747
10,301
12,031
11,203
CLASS 7
18,674
23,270
30,180
25,379
34,210
26,343
CLASS 8
29,628
36,247
39,743
40,243
40,089
37,190
The agencies are proposing to prescribe a fixed payload of 25,000 pounds for Class 7
tractors and 38,000 pounds for Class 8 tractors for their respective test procedures. These
payload values represent a heavily loaded trailer, but not maximum GVWR, since as described
above the majority of tractors "cube-out" rather than "weigh-out."
NHTSA and EPA are also proposing payload requirements for each regulatory
subcategory in the vocational vehicle category. The payloads were developed from Federal
Highway statistics based on the averaging the payloads for the weight classes of represented
within each vehicle category.26 The proposed payload requirement is 5,700 pounds for the Light
Heavy trucks based on the average payload of Class 3, 4, and 5 trucks from Table 3-9. The
proposed payload for Medium Heavy trucks is 11,200 pounds per the average payload of Class 6
trucks as shown in Table 3-9. Lastly the agencies are proposing 38,000 pounds payload for the
Heavy Heavy trucks based on the average Class 8 payload in Table 3-9.
3.5.4 Total Weight
In summary, the total weights of the combination tractors are shown in Table 3-10.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
Table 3-10: Combination Tractor Total weight
MODEL TYPE
Regulatory
Subcategory
Tractor Tare
Weight (Ibs)
Trailer Weight
(Ibs)
Payload (Ibs)
Total Weight (Ibs)
CLASS 8
Sleeper Cab
High Roof
19,000
13,500
38,000
70,500
CLASS 8
Sleeper Cab
Mid Roof
18,750
10,000
38,000
66,750
CLASS 8
Sleeper Cab
Low Roof
18,500
10,500
38,000
67,000
CLASS 8
Day Cab
High Roof
17,500
13,500
38,000
69,000
CLASS 8
Day Cab
Low Roof
17,000
10,500
38,000
65,500
CLASS 7
Day Cab
High Roof
11,500
13,500
25,000
50,000
CLASS 7
Day Cab
Low Roof
11,000
10,500
25,000
46,500
The proposed total weights of the vocational vehicles are as shown in Table 3-11.
Table 3-11: Vocational Vehicle Total Weights
REGULATORY
SUBCATEGORY
Truck Tare
Weight (Ibs)
Payload (Ibs)
Total Weight (Ibs)
LIGHT
HEAVY
10,300
5,700
16,000
MEDIUM
HEAVY
13,950
11,200
25,150
HEAVY
HEAVY
29,000
38,000
67,000
3.6 Heavy-Duty Chassis Test Procedure
The agencies are proposing a chassis test procedure for heavy-duty trucks (with GVWR
greater than 14,000 pounds) in Code of Federal Regulations (CFR), title 40, part 1066. The
chassis test procedure is one of the options being proposed for manufacturers to demonstrate
hybrid powertrain credits. The proposed procedures are adapted from the optional complete
federal vehicle emissions certification for light heavy-duty vehicles (i.e., those with a GVWR of
8,500-14,000 pounds). Details of the light heavy-duty vehicle procedure are found in the Code
of Federal Regulations (CFR), title 40, part 86.1816-05 through part 86.1816-07. Additional test
procedures are described in 40 CFR §86.1863. The proposed test method was further developed
from the draft SmartWay test protocol27, which includes a description of the procedures for
determining the state of charge and net energy change for hybrid vehicles based on SAE test
method 2711."
28
EPA, under the SmartWay program, conducted feasibility testing for the proposed test
method on Class 8 tractors. The testing evaluated track tests against chassis dynamometer tests,
and measurement of CO2 emissions by use of a standard test cell, a portable emissions
monitoring system (PEMS), and calculation from gravimetric measurement of fuel consumption.
Testing issues involving highly variable ambient conditions (i.e. wind speed, temperature, etc.)
suggested that chassis dynamometer tests were preferable for obtaining consistent test results.
Replicate results of the chassis dynamometer procedure demonstrate that the test precision is
typically less than 5%, which is comparable to that of the similar light-duty chassis dynamometer
test procedure, as shown in Table 3-12.
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Draft Regulatory Impact Analysis
Table 3-12 Coefficients of Variation Reported for Chassis Dynamometer Tests Conducted Using the
SmartWay Test Procedure.
METHOD OF
EMISSIONS
MEASUREMENT
Truck number
UCT
LSC
HSC
TEST CELL
29
12.7%
2.0%
1.3%
555
6.2%
3.9%
4.5%
598
1 .6%
1 .4%
1.0%
PEMS
29
1 .8%
1 .2%
0.6%
555
0.8%
0.3%
0.5%
598
2.2%
0.7%
0.5%
GRAVIMETRIC
29
3.9%
2.1%
1 .7%
555
2.2%
3.7%
0.6%
598
2.0%
0.7%
1 .2%
Coefficient of variation is the standard deviation of the test replicates divided by the mean of the test replicates.
UCT - Urban Creep and Transient duty cycle
LSC - Low Speed Cruise duty cycle
HSC - High Speed Cruise duty cycle
The number of heavy-duty chassis dynamometers in the United States is limited. EPA's
investigation found 11 chassis dynamometer sites in North America, including the following:
• Air Resources Board Heavy-Duty Emissions Testing Laboratory in Los Angeles,
California
• California Truck Testing Services in Richmond, California
• Colorado School of Mines, Colorado Institute for Fuels and Research in Golden,
Colorado
• Environment Canada in Ottawa, Ontario, Canada
• Southwest Research Institute in San Antonio, Texas
• West Virginia University Transportable Heavy-Duty Vehicle Emissions Testing
Laboratory
• National Renewable Energy Lab in Golden, Colorado
• University of Houston in Houston, Texas
• US EPA in Research Triangle Park (not in operation yet)
• Argonne National Lab (up to 14,000 Ib.)
• National Vehicle Fuel and Emissions Lab in Ann Arbor, Michigan (up to 14,000 Ib.)
3.7 Hybrid Powertrain Test Procedures
As discussed in Section II, the agencies see an opportunity to create incentives for use of
hybrid powertrains in this proposal, to help drive the technology's advancement. EPA and
NHTSA are proposing two methods to demonstrate benefits of a hybrid powertrain - chassis and
engine testing, and thereby generate credits through the use of such technology. The reduction in
CO2 emissions and fuel consumption demonstrated would be available to use as credits in any
vehicle or engine subcategory. That is, unlike ABT credits, credits generated by use of this
technology would be available for use anywhere in the heavy-duty vehicle and engine sector.
We are proposing the greater portability for these credits in order to create incentives to use this
promising technology and thereby further its acceptance in the heavy-duty sector, with attendant
GHG and fuel consumption reduction benefits.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
The purpose of this testing provision is to allow for evaluation of greenhouse gas and fuel
consumption reducing technologies that are available, but may lack broad market penetration
beyond niche sectors. To effectively incentivize the introduction of this technology, as well as to
accurately characterize its effectiveness, it is important to develop a standardized protocol as a
basis for comparison. As described in the preamble for this rulemaking, the benefit of the
hybridized version of the will be assessed based on a comparison to the conventional version.
The basic methods considered for evaluation include full vehicle chassis testing of the hybrid
system and powertrain evaluation in a configuration that does not include the full vehicle. The
powertrain or "powerpack" testing may be undertaken in one of two ways. A powertrain test cell
capable of accommodating the engine, complete hybrid system (including motor, power
electronics, battery(ies), electronic control system, etc.), and the transmission may be used to
evaluate post-transmission power pack systems. Engine dynamometer test cells may be used to
assess the performance of the engine and hybrid power system with the control volume
extending to just prior to the transmission. The distinction largely being the type of operation the
engine - hybrid system can accommodate. When considering performance of any hybrid
system, the durability of various emissions related system components will need to be included
over the full regulatory useful life. While the industry and component manufacturers may be in
the process of addressing battery technology and lifetime performance, any benefit associated
with the hybrid system will be based on how this performance changes over the life of the hybrid
system and vehicle.
Vehicle Chassis Dynamometer Testing
As a straightforward basis for addressing performance of hybrid systems for greenhouse
gas emissions / fuel consumption reduction potential, the vehicle chassis dynamometer involves
exercising the complete powertrain system within the vehicle for both conventional and hybrid
systems. In this way, actual vehicle performance may be measured using prescribed duty cycles
that have a real-world basis. The certification duty cycles considered for conventional heavy-
duty vehicle certification may be applied to the hybrid vehicle system based on the proposed
chassis testing protocols. The A to B testing would be conducted as described in Figure 3-3
Example of A to B Testing for Chassis or Powertrain Dynamometers below.
Figure 3-3 Example of A to B Testing for Chassis or Powertrain Dynamometers
Conventional Vehicle
Hybrid Vehicle
Curbwt: 21klbs
Pay load: 1k Ibs
Test wt: 22k Ibs
Coastdown Wt: 22k Ibs
GVWR: 33k Ibs
A Test
Curb wt: 22k Ibs
Pay load: 1k Ibs
Test wt: 23k Ibs
Coastdown Wt: 23k Ibs
GVWR: 33k Ibs
BTest
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Draft Regulatory Impact Analysis
This approach is meant to account for the differences in vehicle weight expected for
vehicles equipped with hybrid power systems. In so doing, the capability (e.g. payload, etc.) is
not diminished for testing purposes. The expectation is that the benefit associated with the use of
hybrid system may be characterized by the tractive operation duty cycles and / or the Power-
Take Off duty cycle meant to better reflect the idle work and emissions saved through the use of
a hybrid energy system. Chassis dynamometer testing for hybrid vehicles will be conducted
using standard test protocols as described in SAE J1711 and 2711. To address the use of the
power-take off and the GHG emissions related improvements associated with hybrid power
systems, a separate duty as described in Table 3-14is provided. To address improvements for the
purposes of credit generation, a weighted composite emission level will be used.
Powertrain / Powerpack Evaluation
To address hybrid power system performance for pre-vehicle testing configurations, this
may be accomplished in a powertrain test cell or converted engine dynamometer test cell. There
are various hardware-in-the-loop simulations being contemplated and implemented today,
however the focus of this discussion will be on basic powertrain / powerpack evaluation. Any
pre-vehicle testing provision that incorporates the benefits of hybrid power systems, would need
to address several factors including durability of those components, kinetic energy recovery,
design variety that could be captured using a chassis dynamometer test, and the drive cycle to
appropriately characterize the vehicle activity. The testing methodologies for pre-vehicle hybrid
evaluation currently consist of two equally viable strategies with different implications with
respect to how emissions improvements are characterized. The first system to be discussed is the
pre-transmission powerpack evaluation which incorporates all of the hybrid system components
that exist prior to the transmission in the vehicle. The control volume is drawn so as to include
the battery, battery support and control systems, power electronics, the engine, and motor
generator and hybrid control module. The performance of this system is largely an engine based
evaluation in which emission rates are determined on a brake-specific work basis. As such, the
duty cycles being considered to assess this system performance are engine speed and torque
command cycles. The emissions results associated with the system performance for GHG
pollutants may be measured on brake-specific basis as an absolute test result. This differs from
the approach used for post-transmission testing methods which may be conducted in a
powertrain test cell or using a chassis dynamometer. As this rulemaking does not contemplate
changes to criteria pollutant standards, the duty cycles and measurement methods may be similar
to the criteria pollutants, however the emission results for GHG may be based on this full system
consideration, which is not the case for criteria pollutants. Engine certification for criteria
pollutant standards remain unchanged. It is expected that pre-transmission, parallel hybrids
would be the most likely choice for engine-based hybrid certification.
For powertrain testing to determine hybrid benefit, the components mentioned for
powerpack testing would be included for powertrain testing, as well as the transmission
integrated with the hybrid power system. It is expected that testing could be conducted in a
powertrain test cell which would differ from the traditional engine test cell in that it would need
to accommodate the additional rotational inertia and speeds associated with inclusion of the
vehicle / hybrid transmission with an electric, alternating current dynamometer. Additionally,
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
test cell control systems will need to address all relevant control factors including ways to
integrate vehicle command data into the control strategy for the engine and hybrid transmission
system. This could eventually include the need for vehicle and driver model inclusions into the
control schema for test cell and test article.
Emissions testing for vehicles and hybrid powertrains will require A to B testing to
determine the improvement factor as described in Preamble Section IV using the GEM result for
the base vehicle model as the basis for assessing the CO2 performance improvement versus the
appropriate vocational vehicle standard. Engine performance which includes the pre-
transmission approach for hybrid certification will generate grams per brake-horsepower hour
emissions result that should demonstrate improvement versus the base standard.
3.7.1 Chassis Dynamometer Evaluation
We are proposing that heavy-duty hybrid vehicles be certified using an A to B test
method using a chassis dynamometer for testing vehicles. This concept allows the hybrid
manufacturer to directly quantify the benefit associated with use of their hybrid system on an
application specific basis. The concept would entail exercising the conventional vehicle,
identified as "A", tested over the defined cycles. The "B" vehicle would be the hybrid version of
vehicle "A". To be considered an appropriate "B" vehicle it must be the same exact vehicle
model as the "A" vehicle. As an alternative, if no specific "A" vehicle exists for the hybrid
vehicle that is the exact vehicle model, the most similar vehicle model must be used for
certification. The most similar vehicle is defined as a vehicle with the same footprint, same
payload, same intended service class, and the same coefficient of drag.
To determine the benefit associated with the hybrid system for greenhouse gas (GHG)
performance, the weighted CO2 emissions results from the chassis test of each vehicle would
define the benefit as described below:
1. (CO2 A - CO2 B)/ (CO2 A) = (Improvement Factor)
2. Improvement Factor x Applicable Standard = (g/ton mile benefit)
Similarly, the benefit associated with the hybrid system for fuel consumption would be
determined from the weighted fuel consumption results from the chassis tests of each vehicle as
described below:
3. (Fuel C onsumptionA - Fuel C onsumptionB)/( Fuel ConsumptionA)=
(Improvement Factor)
4. Improvement Factor x F uel C onsumption S tandard = (gallon/ton m ile
benefit)
3.7.1.1 Chassis Dynamometer Drive Cycles
The agencies are proposing two sets of duty cycles to evaluate the benefit depending on
the vehicle application (such as delivery truck, bucket truck, or refuse truck). The key difference
between these two sets of vehicles is that one does not operate a power take-off (PTO) unit while
the other does.
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Draft Regulatory Impact Analysis
A power take off (PTO) is a system on a vehicle that allows energy to be drawn from the
vehicle's drive system and used to power an attachment or a separate machine. Typically in a
heavy-duty truck, a shaft runs from the transmission of the truck and operates a hydraulic pump.
The operator of the truck can select to engage the PTO shaft in order for it to do work, or
disengage the PTO shaft when the PTO is not required to do work. The pressure and flow from
this hydraulic fluid can be used to do work in implements attached to the truck. Common
examples of this are utility trucks that have a lift boom on them, refuse trucks that pick up and
compact trash, and cement trucks that have a rotating barrel. In each case the auxiliary
implement is typically powered by a PTO that uses energy from the truck's primary drive engine.
In most PTO equipped trucks, it is necessary to run the primary drive engine at all times
when the PTO might be needed. This is less efficient than an optimal system. Typical PTO
systems require no more than 19 kW at any time, which is far below the optimal operation range
of the primary drive engine of most trucks. Furthermore, in intermittent operations, the primary
drive engine is kept running at all times in order to ensure that the PTO can operate
instantaneously. This results in excess GHG emissions and fuel consumption due to idle time.
Additionally, idling a truck engine for prolonged periods while operating auxiliary equipment
like a PTO could cause the engine to cycle into a higher idle speed, wasting even more fuel. It
would be possible to hybridize or change the operation of a conventional PTO equipped truck to
lower the GHG emissions and fuel consumption in the real world. However, there is currently no
method for an equipment manufacturer to demonstrate fuel consumption and GHG emissions
reductions due to the application of advanced PTO technology. The proposed drive cycles do not
allow for PTO operation to be included in the test protocol. We are proposing to add a new
optional PTO test to the standard set of test cycles in order for manufacturers of advanced PTO
systems to demonstrate in the laboratory environment fuel consumption and GHG reductions that
would be realized from their systems in the real world. For this reason, the EPA contracted
Southwest Research Institute (SwRI) to study PTO systems on heavy-duty trucks with a goal of
determining an appropriate test cycle.
We worked with SwRI to review the heavy-duty truck market to determine what types of
trucks used PTO's and if the manufacturers thought that there was any possibility of commercial
hybrid PTO applications. In some segments, manufacturers did not think a hybrid PTO was
feasible. On the other hand, there are already utility and refuse trucks in existence that feature
hybrid PTO units. We chose to study the behavior of conventional versions of these trucks in
order to understand their typical operation.
We categorized the trucks based on the PTO opportunity. Trucks where limited PTO
operation makes them infeasible due to low rates of return include dump trucks. Trucks where
PTO operation is infeasible due to high power requirements include blower trucks,
fire/emergency trucks, and concrete mixer trucks. Trucks where there is the possibility of PTO
operation but there was no commercial interest include tow trucks, grapple trucks, and snowplow
trucks.
We selected one utility truck that was in a rental fleet. Over the course of several weeks
this truck was rented to two different customers and used in two different environments. The first
time the truck was rented it was used in a rural setting outside of San Antonio, Texas. The
following week the truck was used in a more urban setting in Fort Worth, Texas. Data was taken
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
from the truck as follows: - Engine Speed, Engine Fuel Rate, Vehicle Speed, PTO Pressure, and
PTO Flow Rate.
From this data we were able to determine how often the truck's engine was running, how
often the PTO was engaged, and how often the boom of the utility truck was being manipulated
by the user. The field data showed that when the truck was operated in the rural setting it had a
much lower rate of utilization that when it was operated in the urban setting. Table 3-13 shows a
breakdown of the operation of the truck in each setting.
Table 3-13 Utility Truck PTO Operation
% Time PTO at "Idle"
% Time PTO working
RURAL SETTING
90%
10%
URBAN SETTING
50%
50%
In order to better understand the field operation of refuse trucks, EPA commissioned
SwRI to study the operation of a refuse hauling truck. SwRI worked with Waste Management in
Conroe Texas to instrument a typical PTO equipped neighborhood pickup refuse hauler. The
truck that we instrumented was equipped with a side-load-arm (SLA). Southwest's research
revealed that approximately 20 percent of the trucks in the industry include an SLA, and the
percentage of trucks with an SLA is increasing. Also, a truck with an SLA is able to service more
homes per day than a standard truck, so as more SLA equipped trucks are added to the fleet, the
total number of trucks will decrease.
The refuse truck was driven on its various routes over the course of a week and the data
recorded. Though the truck operated on different streets and areas within the city of Conroe each
day, the operation characteristics of the truck were uniform day-to-day.
Once the data was collected, definitions of power take-off (PTO) operations were
identified as (1) pump "on" and idle (utility truck), and (2) compactor only, loader only, both
compactor and loader, and idle (refuse truck). Steady-state pressure modes were identified by a
statistical disjoint cluster analysis. Statistical frequency analyses of the in-field data were used to
determine the relative proportion of time allocated to each steady-state mode. The loader and
compactor pressure data from the refuse truck demonstrated cyclical behavior, therefore, a
discrete Fourier transform using the fast Fourier transform (FFT) algorithm was performed on
the loader and compactor data independently. The results of the FFT were used to determine the
frequency of the modes in the test cycle. Information collected on population usage was used to
weight different portions of the composite duty cycle (utility and refuse truck cycles) to reflect
actual field PTO operations.
Based upon the results of the data collection, we decided that a representative duty cycle
for PTO operation would not begin until the engine was fully warmed up. In all cases the trucks
were warmed up before driving, then driven some distance to a location where the PTO was
engaged. Thus, the traction engine was always fully warm before PTO operation commenced.
Based upon the data collection we believe that a representative PTO cycle should test a
PTO that is at operating temperature. In the case of the utility truck, most of the operation is in
an urban environment and about one-half of the operation time is loaded. Thus, the PTO would
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Draft Regulatory Impact Analysis
only operate in a "cold" state for less than 2% of a typical day. The refuse truck showed similar
operation, the PTO was run continuously throughout the eight hour work day resulting in cold
operation of the PTO for less than 2% of the typical day.
EPA and NHTSA are proposing that truck manufacturers be able to test their PTO system
and compare it to a baseline system to generate GHG emissions and fuel consumption credits.
The manufacturer will need to test their system in an emissions cell capable of measuring GHG
emissions. The PTO would be exercised by an auxiliary test bench and commanded to follow a
prescribed cycle. The cycle will be determined by the type of PTO system that is under
consideration. At this time, PTO cycles have been developed for utility trucks and refuse hauling
trucks.
The agencies are proposing a composite PTO cycle to allow PTO manufacturers to earn
credits for GHG emissions. The cycle we are proposing has been weighted based on the utility
truck and refuse truck data in the SwRI report. It was determined that utility truck usage was
approximately 20 percent rural and 80 percent urban. Furthermore, based on the field data
obtained from the test trucks, the utility trucks are expected to use the PTO when performing
boom operations 10 percent of the time in rural settings and 50 percent of the time in urban
settings. The data from the refuse truck in the SwRI report was used to complete the refuse
portion of the cycle. Because the refuse truck used in the data collection had two hydraulic
circuits, one for the load arm and one for the compactor, there are two pressure traces, one for
each circuit. Thus, the PTO test cycle described in Table 3-14 reflects this.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
Table 3-14: Proposed PTO Cycle
Cycle
Simulation
Utility
Utility
Utility
Utility
Utility
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Refuse
Mode
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Time
0
33
40
145
289
361
363
373
384
388
401
403
413
424
442
468
473
486
512
517
530
532
541
550
553
566
568
577
586
589
600
Normalized Pressure,
Circuit 1 (%)
0.0
80.5
0.0
83.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
11.2
29.3
0.0
11.2
29.3
0.0
12.8
12.8
12.8
12.8
0.0
12.8
12.8
12.8
12.8
0.0
0.0
Normalized Pressure,
Circuit 2 (%)
0.0
0.0
0.0
0.0
0.0
13.0
38.0
53.0
73.0
0.0
13.0
38.0
53.0
73.0
0.0
0.0
0.0
0.0
0.0
0.0
11.1
38.2
53.4
73.5
0.0
11.1
38.2
53.4
73.5
0.0
0.0
The protocol for testing the PTO system will be similar to chassis testing. The vehicle
will be positioned such that the exhaust system can be attached to exhaust emission analyzers.
This can be done using, but does not necessarily require, a chassis dynamometer. The PTO
system will be disconnected from the truck's work absorbing apparatus and connected to a bench
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Draft Regulatory Impact Analysis
that will provide energy absorption to the PTO system. For trucks with one hydraulic circuit in
the PTO system, they will be hooked up to the utility/compactor side of the PTO bench. Trucks
with two hydraulic circuits will be hooked up to both circuits on the PTO bench. A schematic of
this bench can be seen in Appendix I. The vehicle will be pre-conditioned at ambient conditions
and then the engine will be run until it is at operating temperature. The PTO will then be
exercised until the working fluid and or driving mechanism of the PTO is up to operating
temperature. The fully warmed up operating temperature may be defined by the manufacturer or
may be assumed to be 150°C. The test will then commence. We believe that a "hot-start" test is
appropriate because our data analysis found that trucks equipped with PTO's are nearly always
warmed up before the PTO is used, and that cold PTO operation makes up less than 2% of a
PTO's typical daily usage.
The PTO would be manipulated by the operator to the prescribed duty cycle. GHG
emissions and fuel consumption will be measured as well as criteria pollutants. GHG emissions
and fuel consumption would be reported to determine credits; criteria pollutants will simply be
reported.
In order to gain credits the manufacturer would have to demonstrate how a truck with a
conventional PTO system would perform over the same duty cycle. Both sets of data will need to
be measured and reported to EPA and NHTSA in order to claim GHG emission and fuel
consumption credits.
The first set of proposed duty cycles would apply to the hybrid powertrains used to
improve the motive performance of the vehicle (such as pickup and delivery trucks). The typical
operation of these vehicles is very similar to the proposed drive cycles. Therefore, the agencies
are proposing to use the vocational vehicle weightings for these vehicles, as shown in Table 3-
12. We are using the proposed regulatory vocational vehicle classifications for the ABT
vocational vehicle classification. Hybrid vehicles used in applications such as utility and refuse
trucks tend to have additional benefit associated with use of stored energy, which avoids main
engine operation and related CO2 emissions and fuel consumption. To appropriately address
these alternative sources for benefits, exercising the conventional and hybrid vehicles using their
PTO would help to quantify the benefit to GHG emissions and fuel consumption reductions. The
duty cycle proposed to quantify the hybrid CO2 and fuel consumption impact over this broader
set of operation would be the three primary cycles plus a PTO duty cycle. The proposed
weighting for the cycle is based on data gathered during the SwRI study. Based on fleet owner
information, the agencies estimate that the utility trucks are used 20 percent of the time in rural
operations and 80 percent of the time in urban operations. The SwRI study found that utility
trucks spent 5.5 percent of the time operating the PTO in rural settings and 34.4 percent of the
time on in urban settings. This produces an overall percent PTO on time for utility trucks of 28.6
percent. The study found that the refuse trucks have the PTO on 26.7 percent of the time. The
agencies weighted each truck type's percent on time based on 40 percent refuse trucks and 60
percent utility trucks to establish an overall 28 percent on-time. Therefore, the agencies are
proposing that the PTO cycle be weighted at 28 percent and weight the other three cycles for the
remaining 72 percent. The proposed weightings for the hybrids with and without PTO are
included in Table 3-15.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
Table 3-15: Proposed Drive Cycle Weightings for Hybrid Vehicles
Vocational Vehicles without PTO
Vocational Vehicles with PTO
Transient
42%
30%
55mph
21%
15%
65 mph
37%
27%
PTO
0%
28%
3.7.2
Engine Dynamometer Evaluation
The engine test procedure we are proposing for hybrid evaluation involves exercising the
conventional engine and hybrid-engine system based on an engine testing strategy. The basis for
the system control volume, which serves to determine the valid test article, will need to be the
most accurate representation of real world functionality. An engine test methodology would be
considered valid to the extent the test is performed on a test article that does not mischaracterize
criteria pollutant performance or actual system performance. Energy inputs should not be based
on simulation data which is not an accurate reflection of actual real world operation. It is clearly
important to be sure credits are generated based on known physical systems. This includes
testing using recovered vehicle kinetic energy. Additionally, the duty cycle over which this
engine-hybrid system will be exercised must reflect the use of the application, while not
promoting a proliferation of duty cycles which prevent a standardized basis for comparing hybrid
system performance. The agencies are proposing the use of the Heavy-Duty Engine FTP cycle
for evaluation of hybrid vehicles, which is the same test cycle proposed for engines used in
vocational vehicles. It is important that introduction of clean technology be incentivized without
compromising the program intent of real world improvements in GHG and fuel consumption
performance.
Pre-Transmission Power-Pack Testing
Pre-transmission power-pack testing would involve the power system components
included in the engine test cell up to the transmission (pre-gearbox) as the valid test article. The
engine power would serve as the basis for assessing brake specific emissions performance for
criteria pollutants as the agencies are not proposing changes to the criteria pollutant standards.
For GHG pollutant performance, the entire power system pre-gearbox can serve as the basis for
the brake-specific emissions performance as seen in Figure 3-4 Pre-Transmission Parallel
Hybrid Power Pack Test Configuration. Testing using this method, as described previously,
could utilize existing engine certification duty cycles. The applicability to the broader set of
applications could be based largely on the approach taken with today's engine certification.
Changes to how the engine certification would be conducted to address energy capture and idle
operation will need to be evaluated as a complete protocol is developed. In conducting hybrid
testing it is important for the RESS to have a state of charge at the end of the certification test to
have a net change in the state of charge of less than 1%. It has been suggested to the agencies
that energy capture for pre-transmission, parallel hybrid, power-pack testing could be based on
one of the following three approaches: allow capture up to capability of system, place upper
limit on energy captured over cycle based on available brake energy in real world cycles, or
9Q
calculate second-by-second available regeneration torque based on FTP .
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Draft Regulatory Impact Analysis
Figure 3-4 Pre-Transmission Parallel Hybrid Power Pack Test Configuration
Hyftfid
Conrcl
Rear wnee* Drtv*
Generator comtxsli&n
Engne
Source: Cummins Incorporated's White Paper: Regulation of emissions from commercial hybrid vehicles, August 9, 2010
Post-Transmission Power-Pack Testing
Post-transmission power-pack testing would involve the power system components
included in the engine test cell up to and including the transmission (potentially still pre-gearbox)
as the valid test article. The inclusion of the transmission in the hybrid system for certification
potentially introduced a new entity to the certification and a new aspect to of test article control.
With the additional components, the traditional FTP is not viable, in its current form for
exercising a more complete powertrain. A vehicle-like duty cycle which provides the
appropriate speeds and torques to more appropriately match field operation would be needed.
The test article anticipated for this configuration, would more closely match complete hardware
in the loop evaluation methods contemplated in other testing regimes. The ability to obtain
actual performance results versus simulations of actual results in a test environment largely
center on evaluating components with native intelligence rather than simulating their control
system.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
Figure 3-5 Hardware-in-the-Loop Post-Transmission Powerpack Test Configuration
Engine Dyno Control
Engine load time trace: FTP
Analog absorption torque cmd
Analog throttle cmd
MIL Dyno Control
Vehicle speed time trace
Model Engine & brake loads
Analog absorption torque cmd •
J1939 Hybrid & brake cmd -
- ****»
Inn
I "I AA : -if:::!::;:
Source: Eaton Presentation to EPA, September 15, 2010
3.8 HD Pickup Truck and Van Chassis Test Procedure
The agencies are proposing that HD pickup trucks and vans demonstrate compliance
using a chassis test procedure. For each test vehicle from a family required to comply with the
proposed GHG and fuel consumption requirements, the manufacturer would supply
representative road load forces for the vehicle at speeds between 15 km/hr (9.3 mph) and 115
km/hr (71.5 mph). The road load force would represent vehicle operation on a smooth level road,
during calm winds, with no precipitation, at an ambient temperature of 20 degree C (68 degree
F), and atmospheric pressure of 98.21 kPa. Road load force for low speed may be extrapolated.
The dynamometer's power absorption would be set for each vehicle's emission test
sequence such that the force imposed during dynamometer operation matches actual road load
force at all speeds. Required test dynamometer inertia weight class selections are determined by
the test vehicle test weight basis and corresponding equivalent weight.
3.8.1 LHD UDDS and HWFE Testing
The HDDS dynamometer run consists of two tests, a "cold" start test after a minimum
12-hour and a maximum 36-hour soak according to the provisions of Sec. Sec. 86.132 and
86.133, and a "hot" start test following the "cold" start by 10 minutes. Engine startup (with all
accessories turned off), operation over the HDDS, and engine shutdown constitutes a complete
cold start test. Engine startup and operation over the first 505 seconds of the driving schedule
complete the hot start test. The driving schedule for the EPA Urban Dynamometer Driving
Schedule is contained in Appendix I of 40 CFR part 86. The driving schedule is defined by a
smooth trace drawn through the specified speed vs. time relationship. The schedule consists of a
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Draft Regulatory Impact Analysis
distinct non-repetitive series of idle, acceleration, cruise, and deceleration modes of various time
sequences and rates.
The Highway Fuel Economy Dynamometer Procedure (HFET) consists of
preconditioning highway driving sequence and a measured highway driving sequence. The
HFET is designated to simulate non-metropolitan driving with an average speed of 48.6 mph and
a maximum speed of 60 mph. The cycle is 10.2 miles long with 0.2 stop per mile and consists of
warmed-up vehicle operation on a chassis dynamometer through a specified driving cycle. The
Highway Fuel Economy Driving Schedule is set forth in Appendix I of 40 CFR Part 600. The
driving schedule is defined by a smooth trace drawn through the specified speed versus time
relationships.
Practice runs over the prescribed driving schedules may be performed at test point,
provided an emission sample is not taken, for the purpose of finding the appropriate throttle
action to maintain the proper speed-time relationship, or to permit sampling system adjustment.
Both smoothing of speed variations and excessive accelerator pedal perturbations are to be
avoided. The driver should attempt to follow the target schedule as closely as possible. The
speed tolerance at any given time on the dynamometer driving schedules specified in Appendix I
of parts 40 and 600 is defined by upper and lower limits. The upper limit is 2 mph higher than
the highest point on trace within 1 second of the given time. The lower limit is 2 mph lower than
the lowest point on the trace within 1 second of the given time. Speed variations greater than the
tolerances (such as may occur during gear changes) are acceptable provided they occur for less
than 2 seconds on any occasion. Speeds lower than those prescribed are acceptable provided the
vehicle is operated at maximum available power during such occurrences.
3.8.2 LHD UDDS and HWFE Hybrid Testing
Since LHD chassis certified vehicles share test schedules and test equipment with much
of Light-Duty Vehicle testing, EPA believes it is appropriate to reference SAE J1711
"Recommended Practice for Measuring the Exhaust Emissions and Fuel Economy of Hybrid-
Electric Vehicles, Including Plug-in Hybrid Vehicles" instead of SAEJ2711 "Recommended
Practice for Measuring Fuel Economy and Emissions of Hybrid-Electric and Conventional
Heavy-Duty Vehicles".
3.8.2.1 Charge Depleting Operation - FTP or "City" Test and HFET or "Highway"
Test
The EPA would like comment on incorporating by reference SAE J1711 chapters 3 and
4, as published June 2010, testing procedures for Light-Heavy-Duty chassis certified vehicles
with the following exceptions and clarifications:
Test cycles will continue until the end of the phase in which charge sustain operation is
confirmed. Charge sustain operation is confirmed when one or more phases or cycles satisfy the
Net Energy Change requirements below. Optionally, a manufacturer may terminate charge
deplete testing before charge sustain operation is confirmed provided that the Rechargeable
Energy Storage System (RESS) has a higher State of Charge (SOC) at charge deplete testing
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
termination than in charge sustain operation. In the case of Plug In Hybrid Electric Vehicles
(PHEV) with an all electric range, engine start time will be recorded but the test does not
necessarily terminate with engine start. PHEVs with all electric operation follow the same test
termination criteria as blended mode PHEVs. Testing can only be terminated at the end of a test
cycle. The Administrator may approve alternate end of test criteria.
For the purposes of charge depleting CC>2 and fuel efficiency testing, manufacturers may
elect to report one measurement per phase (one bag per HDDS). Exhaust emissions need not be
reported or measured in phases the engine does not operate.
End of test recharging procedure is intended to return the RESS to a full charge
equivalent to pre test conditions. The recharge AC watt hours must be recorded throughout the
charge time and soak time. Vehicle soak conditions must not be violated. The AC watt hours
must include the charger efficiency. The measured AC watt hours are intended to reflect all
applicable electricity consumption including charger losses, battery and vehicle conditioning
during the recharge and soak, and the electricity consumption during the drive cycles.
Net Energy Change Tolerance (NEC), is to be applied to the RESS to confirm charge
sustaining operation. The EPA intends to adopt the 1% of fuel energy NEC state of charge
criteria as expressed in SAE J1711. The Administrator may approve alternate NEC tolerances
and state of charge correction factors.
3.8.2.2 Hybrid Charge Sustaining Operation - FTP or "City" Test and HFET or
"Highway" Test
The EPA proposes to incorporate by reference SAE J1711 chapters 3 and 4 for
definitions and test procedures, respectively, where appropriate, with the following exceptions
and clarifications.
The EPA proposes to adopt the 1% of fuel energy NEC state of charge criteria as
expressed in SAEJ1711. The Administrator may approve alternate NEC tolerances and state of
charge correction factors.
Preconditioning special procedures are optional for traditional "warm" test cycles that are
now required to test starting at full RESS charge due to charge depleting range testing. If the
vehicle is equipped with a charge sustain switch, the preconditioning cycle may be conducted per
600. Ill provided that the RESS is not charged. Exhaust emissions are not taken in
preconditioning drives. Alternate vehicle warm up strategies may be approved by the
Administrator.
State of Charge tolerance correction factors may be approved by the Administrator. RESS
state of charge tolerances beyond the 1% of fuel energy may be approved by the Administrator.
The EPA is seeking comment on modifying the minimum and maximum allowable test
vehicle accumulated mileage for both EVs and PHEVs. Due to the nature of PHEV and EV
operation, testing may require many more vehicle miles than conventional vehicles.
Furthermore, EVs and PHEVs either do not have engines or may use the engine for only a
fraction of the miles driven.
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Draft Regulatory Impact Analysis
Electric Vehicles and PHEVs are to be recharged using the supplied manufacturer
method provided that the methods are available to consumers. This method could include the
electricity service requirements such as service amperage, voltage, and phase. Manufacturers
may employ the use of voltage regulators in order to reduce test to test variability with prior
Administrator approval.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Test Procedures
References
1 Coordinating Research Council, Inc. Phase 1 of the Advanced Collaborative Emissions Study. June 2009.
2 Fiest, M, C. Sharp, R. Mason, J. Buckingham. Determination of PEMS Measurement Allowances for Gaseous
Emissions Regulated Under the Heavy-Duty Diesel Engine In-Use Testing Program.2007. Table 122 and 123.
3 § 86.004-28
4 U.S. EPA. Truck and Trailer Roof Height Match Analysis Memorandum from Amy Kopin to the Docket, August
9, 2010. Docket Identification Number EPA-HQ-OAR-2010-0162-0045.
5 SAE Recommended Practice 1263, Road Load Measurement and Dynamometer Simulation Using Coastdown
Techniques, January 2009
6 SAE Recommended Practice J2263. Road Load Measurement Using Onboard Anemometry and Coastdown
Techniques. December 2008.
7 "Heavy-Duty Coastdown Test Procedure Development," Docket Number EPA-HQ-OAR-2010-0162-0144.
o
"Lecture Notes in Applied and Computational Mechanics, The Aerodynamics of Heavy Vehicles II: Trucks,
Buses, and Trains; DOI: 10.1007/978-3-540-85070-0_33; "Applicability of Commercial CFD tools for assessment
of heavy vehicle aerodynamic characteristics" as created by the University of Chicago as Operator of Argonne
National Laboratory ("Argonne") under contract No. W-31-109-ENG-38 with the U.S. Department of Energy."
9 For more information, see CFR Title 40, Part 86.129-00 (e)(l).
10 2010 NAS Report. Finding 2-4 on page 39.
11 SAE International, 2006, Rolling Resistance measurement Procedure for Passenger Car, Light Truck, and
Highway Truck and Bus Tires, SAE J1269, 2006-09
12 ISO, 2009, Passenger Car, Truck, and Bus Tyres - Methods of Measuring Rolling Resistance - Single Point Test
and Correlation of Measurement Results: ISO 28580:2009(E), First Edition, 2009-07-01
13 NHTSA, 2009. "NHTSA Tire Fuel Efficiency Consumer Information Program Development: Phase 1 -
Evaluation of Laboratory Test Protocols." DOT HS 811 119. June, (www.regulations.gov, Docket ID: NHTSA-
2008-0121-0019).
14 SAE International, 1999, Stepwise Coastdown Methodology for Measuring Tire Rolling Resistance,. SAE J2452,
1999-06
15 ISO, 2005, Passenger Car, Truck, Bus, and Motorcycle Tyres - Methods of Measuring Rolling Resistance, ISO
18164:2005(E)
16 Based on MOVES analysis.
17 University of California Riverside. Analysis of Heavy Duty Diesel Truck Activity and Emissions Data. 2006.
18 Gaines, L. "Estimation of Fuel Use by Idling Commercial Trucks", Paper 06-2567. 2006.
19 Franzese, O., H. Knee, L. Slezak. Effect of Tires on Class-8 Heavy Truck Fuel Efficiency. July 2009. Last
viewed on May 1, 2010 at http://info.ornl.gov/sites/publications/files/Pub20686.pdf
20 U.S. Department of Energy. "Transportation Energy Data Book. Edition 28 - 2009. Table5.ll. Lastviewedon
Mary 1, 2010 athttp://cta.ornl.gov/data/tedb28/Edition28_Chapter05.pdf
21 Environmental Defense Fund. "Greenhouse Gas Management for Medium-Duty Truck Fleets." Viewed at
http://edf.org/documents/10860_fleets-med-ghg-management.pdf. Page 6.
22ICF International. Investigation of Costs for Strategies to Reduce Greenhouse Gas Emissions for Heavy-Duty
On-Road Vehicles. July 2010. Pages 4-16. Docket Identification Number EPA-HQ-OAR-2010-0162-0044.
3-45
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Draft Regulatory Impact Analysis
23 MJ. Bradley & Associates. Setting the Stage for Regulation of Heavy-Duty Vehicle Fuel Economy and GHG
Emissions: Issues and Opportunities. February 2009. Page 35. Analysis based on 1992 Truck Inventory and Use
Survey data, where the survey data allowed developing the distribution of loads instead of merely the average loads.
24 The U.S. Federal Highway Administration. Development of Truck Payload Equivalent Factor. Table 11. Last
viewed on March 9, 2010 at
http://ops.fhwa. dot. gov/freight/freight_analysis/faf/faf2_reports/reports9/s510_ll_12_tables.htm
25 Excerpted from The U.S. Federal Highway Administration. Development of Truck Payload Equivalent Factor.
Table 11. Last viewed on March 9, 2010 at
http://ops.fhwa. dot. gov/freight/freight_analysis/faf/faf2_reports/reports9/s510_ll_12_tables.htm
26 The U.S. Federal Highway Administration. Development of Truck Payload Equivalent Factor. Table 11. Last
viewed on March 9, 2010 at
http://ops.fhwa. dot. gov/freight/freight_analysis/faf/faf2_reports/reports9/s510_ll_12_tables.htm
27 U.S. Environmental Protection Agency, SmartWay Fuel Efficiency Test Protocol for Medium and Heavy Duty
Vehicles - Working Draft, EPA420-P-07-003, November 2007,
http://www.epa.gov/smartwav/transport/documents/tech/420p07003.pdf. site accessed September 16, 2009.
28 SAE Recommended Practice for Measuring Fuel Economy and Emissions of Hybrid Electric and Heavy-Duty
Vehicles, September 1, 2002
29 Cummins Incorporated, Regulation of Emissions from Commercial Hybrid Vehicles, August 2010
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
Chapter 4: Vehicle Simulation Model
4.1 Purpose and Scope
4.1.1 Methods to Assess a Truck's Greenhouse Gas Emissions
An important aspect of a regulatory program is to determine the environmental benefits
of heavy-duty truck technologies through testing and analysis. There are several methods
available today to assess greenhouse gas emissions from trucks. Truck fleets today often use
SAE J1321 test procedures to evaluate criteria pollutant emissions changes based on paired truck
testing.l Light-duty trucks are assessed using chassis dynamometer test procedures.2 Heavy-
duty engines are evaluated with engine dynamometer test procedures.3 Most large truck
manufacturers employ various computer simulation methods to estimate truck efficiency. Each
method has advantages and disadvantages. This section will focus on the use of truck simulation
modeling for assessing tailpipe GHG emissions and fuel consumption.
4.1.2 Proposal to Use Simulation Model to Certify Vocational Trucks and
Combination Tractors
The agencies are proposing to use a simulation model as the primary tool to certify
vocational and combination tractor heavy-duty vehicles (Class 2b through Class 8 heavy-duty,
vehicles that are not heavy-duty pickups or vans). The advantages of modeling for these vehicles
include:
• The simulation tool can model a wide range of vehicle types.
• The vehicle components can be easily changed to match the features of a given
vehicle.
• The entire configuration of the vehicle can also be changed, so the same program
can model a Class 4 pickup and delivery truck and a Class 7 or 8 combination
truck with appropriate input parameter changes. This allows the agencies to use
the same program to develop and certify all of the heavy-duty vehicles.
• The modeling tool also accommodates different drive cycles.
• It can significantly reduce truck manufacturer's burden to conduct heavy-duty
chassis dynamometer tests.
4.1.3 Chapter Overview
The scope of this chapter will discuss truck simulation models and their feasibility, the
truck simulation tool, and application of models to develop certification options.
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Draft Regulatory Impact Analysis
4.2 Model Code Description
4.2.1 Engineering Foundations of Model
A number of commercially available heavy-duty vehicle simulation tools are based on
MATLAB/Simulink-based programs that can model a wide variety of vehicles, from medium-
duty to Class 8 trucks.4'5 Generally, each vehicle component is depicted by a generic Simulink
model that can be modified using an initialization file. The user can utilize pre-determined
initialization files for a given component, or modify them to reflect their particular situation.
The following section describes the system required to model a heavy-duty non-hybrid truck.
Once the vehicle has been specified, the user selects a drive cycle (which they can also modify)
and runs the program.
EPA has developed a forward-looking MATLAB/Simulink-based model termed
Greenhouse gas Emissions Model (GEM) for Class 2b-8 vehicle compliance. GEM uses the
same physical principles as many other existing vehicle simulation models to derive governing
equations which describe driveline components, engine, and vehicle. These equations are then
integrated in time to calculate transient speed and torque.
4.2.2 Vehicle Model Architecture
Table 4-1 outlines the Class 2b-8 vehicle compliance model architecture, which is
comprised of six systems: Ambient, Driver, Electric, Engine, Transmission, and Vehicle. With
the exception of "Ambient" and "Driver," each system consists of two to four component
models. The function of each system and their respective component models, wherever
applicable, is discussed in this section.
Table 4-1: Vehicle Model Architecture
System
Ambient
Driver
Electric
Engine
Transmission
Vehicle
Component Models
none
none
Starter; Electrical Energy System; Alternator;
Cylinder; Accessory (mechanical)
Clutch; Gearbox
Chassis; Final Drive
Accessory (electrical)
Ambient - This system defines ambient conditions such as pressure, temperature, and
road gradient, where vehicle operations are simulated.
Driver - GEM is a forward-looking driving model. Rather than constantly matching the
exact drive cycle, the driver model considers the current speed and the desired future speed to try
to predict the necessary power required to close the gap and follow the driving trace. If the
driver misses the target, a different power request is sent to the engine and/or brakes are applied.
This search for the proper vehicle speed occurs at every simulation time step. The feedback loop
uses a PID controller.
The "Electric" system consists of four components: Starter, Electrical Energy System,
Alternator, and Electrical Accessory
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
Starter - This models the starter for the engine, which is identical for most vehicles.
Electrical Energy System - GEM simulates a standard 12 or 24 volt lead-acid battery,
which provides currents to the starter and electrical systems for engine starting, lighting, and
vehicle controls. This module estimates State-of-Charge (SOC), internal ohmic resistance and
open circuit voltage, voltage and current of electrical energy storage system.
Alternator - This models the alternator that generates electricity for the battery and
electrical system. The model calculates voltage and current of the AC alternator based on
alternator performance maps and charge control strategy.
Electrical Accessory - All vehicles have a number of electrical loads, some of which are
necessary to operate the vehicle. The engine control unit (ECU), fuel injectors and fuel pump for
instance are electrical loads that are constantly on the battery, and these are already taken into
account in the fuel map.
The "Engine" system consists of two components: Cylinder and Mechanical Accessory
Cylinder - The cylinder model is based on a fuel map and torque curves at wide open
throttle (full load) and closed throttle (no load). The engine fuel map features three sets of data:
engine speed, torque, and fueling rate at pre-specified engine speed and torque intervals. It is not
a physics-based model and does not attempt to model in-cylinder combustion process. The
engine torque and speed are used to select a fuel rate based on the fuel map. This map is
adjusted automatically by taking into account three different driving types: acceleration, braking,
and coasting. The fuel map, torque curves, and the different driving types are pre-programmed
into GEM for several different default engines.
Mechanical Accessory - Most vehicles run a number of accessories that are driven via
mechanical power from the engine. Some of these accessories are necessary for the vehicle to
run, like the coolant pump, while others are only used occasionally and at the operator's
discretion such as the air conditioning compressor. Some heavy-duty vehicles also use Power
Take Off (PTO) to operate auxiliary equipment, like booms, and these would also be modeled as
a mechanical accessory.
The manual "Transmission" system consists of two components: a Clutch and a Gearbox
Clutch - This component model simulates the clutch for a manual transmission.
Gearbox - A simple gearbox model is used for a manual transmission, and the number of
gears and gear ratios is predefined in GEM. This component model consists of a map using
gearbox speed and torque as inputs to model the efficiency of each gear.
The "Vehicle" system consists of two components: Chassis and Final Drive
Chassis - This portion models the shell of the vehicle including the tires. The drag
coefficient, mass of the vehicle, frontal area and other parameters are housed in this component.
For tire simulation, the user specifies the configuration of each axle on the vehicle, including the
tire diameter and the rolling resistance.
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Draft Regulatory Impact Analysis
Final Drive - The gear ratio for the differential can be specified directly by the user. The
efficiency is defined by a map based on the transmission output speed and torque.
4.2.3 Capability, Features, and Computer Resources
The EPA/NHTSA vehicle compliance tool is a flexible simulation platform that can
model a wide variety of vehicles from Class 2b to Class 8 trucks. The key to this flexibility is
the MATLAB component files that can be modified or adjusted to accommodate vehicle-specific
information. Parameters such as vehicle weight, fuel map settings, and tire radius, for instance,
can all be changed in this fashion. However, since the proposed rule specifies applicable drive
cycles (the Transient mode, as defined by ARB in the HHDDT cycle, a constant speed cycle at
65 mph and a 55 mph constant speed mode), manufacturers cannot select alternative drive cycles
(although the model is capable of incorporating other drive cycles should the agencies decide
after considering public comment that additional or different drive cycles are necessary).
Similarly, manufacturers cannot alter any default settings which are established by the agencies.
After running the simulation, GEM tracks information about each component and about
the system as a whole. Information like CC>2 emissions, fuel consumption, and fidelity to the
drive cycle are immediately available on the results screen. The output from each run can be
saved as a comma-separated values (CSV) file or an Excel file.
The system requirements for the MATLAB version of GEM include a minimum RAM of
1 GB, MATLAB, Simulink and Stateflow (version 2009b or later), and approximately 250 MB
of disk storage.7'8'9 The simulation takes between 10 and 20 seconds per drive cycle, depending
on the cycle duration. No separate license is required to run the program other than for
MATLAB, Simulink, and Stateflow. Although the source code is available to users, all of the
component initialization files, control strategies and the underlying
MATLAB/Simulink/Stateflow-based models should remain fixed and should not be manipulated
by the users when assessing their compliance. For these reasons, a stand-alone executable model
independent of MATLAB/Simulink/Stateflow licenses has been created. Only the executable
can be used when producing official truck certification results. The agencies are proposing that
the manufacturers submit both the input parameters and the modeling results.
4.3 Feasibility of Using a Model to Simulate Testing
4.3.1 Procedure for Model Validation
The agencies have assessed the predictive utility of the GEM model by comparing its
prediction with actual test data. The agencies plan to continue this effort between proposal and
final rule, and also plan to continue the supplemental validation effort where GEM predictions
are compared with those of a widely-used commercial model. Validation is considered
successful when the differences between the simulation and the test data are within the error
limits of the test data. Before the model is validated, a quality assurance check for the input data
needs to be made, which includes the following steps.
• Alignment of data from different sources such as dynamometer, emissions
benches, portable emissions measurement systems, or engine control units;
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
• Ensuring that the vehicle and engine powertrain parameters, such as vehicle
weight, transmission, driveline, tire, and inertia for various rotational parts etc.,
represent the actual vehicle being modeled;
• Selection of the proper sensor when the same parameter is recorded by different
sources and calibration of the sensors to the same reference value;
• Quantification of the uncertainty of each sensor.
After the operating conditions of the vehicle components have been successfully
reproduced by the model, the final results of the vehicle simulation are compared with results of
a representative vehicle test. If the difference is within the test error, the model can be
considered validated and can be used for vehicle simulations.
In the past two years, the agencies have been striving to gather as much test data as
possible from vocational trucks and combination tractors. Although it would be optimal if the
primary source of data for validating the GEM simulation tool comes from chassis dynamometer
testing or real world driving of these vehicles, the process involved in data acquisition for the
wide ranging heavy-duty vocational truck and combination tractor categories, which includes
vehicle identification, procurement, coastdowns for generating dynamometer coefficients,
emissions sampling, etc., has necessarily been tedious and time-consuming. 10'u Although the
agencies are endeavoring to obtain test data for all categories of vocational trucks and
combination tractors, the agencies are also using additional approaches to make as robust a
validation effort as possible. One of these additional approaches is to compare GEM results with
those of another well known industrial-standard simulation model. The agencies have selected
I r\
the GT-Drive model developed by Gamma Technologies for this purpose.
4.3.2 Validation of EPA and NHTSA Vehicle Compliance Model
At this point, the agencies have GHG and fuel consumption test data from a high-roof
Class 8 sleeper combination tractor, designated as "555" that was run on the drive cycles
proposed for certification, i.e., transient cycle and steady-state cycles with 65 and 55 mph cruise
speeds. The testing was conducted for EPA by Southwest Research Institute (SwRI) in which
emissions, fuel consumption, and engine operating parameters were measured in a heavy-duty
chassis dynamometer test cell.13 The Class 8 combination tractor is a 2008 International Prostar
equipped with a 2007 Cummins ISX engine, and this tractor was chassis tested using
dynamometer set coefficients derived from onroad coastdown testing results obtained by SwRI
on this same tractor combined with a 53 feet long box trailer, thus the resulting data reflect a
high-roof sleeper tractor combined with a box trailer configuration. Table 4-2 provides further
details on the combination tractor and the engine which were tested at SwRI and the parameters
which were modeled in both GEM and GT-Drive.
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Draft Regulatory Impact Analysis
Table 4-2: Truck 555 Tractor and Engine Specifications
Tractor/ Model
Year Model
Type
Engine OEM
Engine Family
Displacement
Horsepower Rating
Final Drive
Transmission Model
Transmission Type
Steer Axle Tires
Tire Size
Front Rims / make
Drive Axle Tires
Tire Size
Drive Rims / Make
International Prostar
2008
High Roof Sleeper
Cummins ISX
7CEXH0912XAK
15 liters
408 @ 1 ,800 RPM
2.64
Fuller FR1 521 OB
10 speed manual
Michelin XZA3
275/80/22.5
Accuride DOT T
Michelin XDA Energy
275/80/22.5
Accuride DOT T
Table 4-3 compares the chassis test data with results from GEM obtained using the
methodology proposed.13 As shown in Table 4-3, reasonably good comparisons are obtained.
The predicted results are within the same range of variability as run-to-run variability exhibited
in chassis dynamometer testing (± 5 percent for Truck Number 555; see DRIA section 3.6).
Table 4-3: Fuel Economy (mpg) Comparison between Test Data and GEM Simulation Results
Cycles
Transient
65 mph
55 mph
ProStar @ SwRI
(Chassis Test )
3.51
6.98
8.35
GEM
3.51
6.82
8.05
Difference
0.0%
2.3%
3.6%
The agencies also compared the results from GEM with the results obtained from
modeling the same tractor configuration using GT-Drive. As shown in Table 4-4, a very good
agreement between these two models is obtained. This comparison essentially demonstrates that
both models produce very similar or even identical results. The agencies thus regard comparison
of GEM results and GT-Drive results as a useful supplement to direct validation efforts. It
should be noted, however, that the GT-Drive model is not suitable for regulatory purposes since
(among other things) its code is proprietary so that the necessary degree of public transparency is
not possible.
Table 4-4: Fuel Economy (mpg) Comparison between GT-Drive and GEM Simulation Results
Cycles
Transient
65 mph
55 mph
GT-Drive
3.51
6.82
8.13
GEM
3.51
6.82
8.05
Difference
0.0%
0.0%
1 .0%
The agencies thus view the results from the two comparisons as a (admittedly still partial)
validation of the GEM simulation tool.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
4.4 EPA and NHTSA Vehicle Compliance Model
Although several existing heavy-duty vehicle simulation models are widely accepted by
the research community and industry, one drawback is that their codes are not designed for the
proposed regulatory program. For heavy-duty vehicles to be manufactured beginning in the
2014 MY timeframe, the proposed compliance approach is done through simulation based on a
few user input parameters, including rolling resistance, aerodynamic drag coefficient, and
vehicle weight. The comprehensive input structures of many commercially available models are
more complicated than necessary for purposes of the proposed rule and may present an
unnecessarily steep learning curve to the users. Therefore, EPA and NHTSA have sought to
develop a forward-looking, compliance-focused vehicle model internally which includes only
those technical features required for compliance purposes. The model structure and input are
straightforward. The proposed model has not yet been peer reviewed but is expected to be
before any final rule is issued. The following section describes this proposed compliance model
which is to undergo a peer review process in the coming months.
4.4.1 Vehicle Model for 2014 MY Time Frame
After the agencies established the list of required input parameters from vehicle
manufacturers for tractor and vocational truck certification, EPA proceeded with the
development of a heavy-duty truck simulation package which produces GHG output comparable
to many sophisticated forward-looking models, but eliminates the multitude of features that are
needed for research and development, but that are overly complicated and not required for
certification purposes.
Certification-geared truck models have been created in MATLAB/Simulink environment
for vehicles with both manual and automatic transmissions. MATLAB scripts are also created,
which control pre- and post-processing of truck simulations. The function of the MATLAB pre-
processing scripts is to gather all the necessary component model parameters, including agency-
defined fuel maps as well as manufacturer inputs (e.g., Cd, Crr, etc.). Once all the parameters
are downloaded into the MATLAB workspace, the MATLAB/Simulink/Stateflow model is run
to generate GHG emissions and fuel consumption for each of the three drive cycles after which
the post-processing MATLAB scripts perform the calculation of individual cycle and cycle
weighted fuel economy, fuel consumption and CC>2 emissions as per the EPA/NHTSA
regulatory scheme in mile/gallon, gallon/ton-mile, gram CCVton-mile and generate graphs
displaying how the certifying vehicle follows the three drive cycle simulations. Based on the
general truck usage pattern, EPA and NHTSA have defined three sets of cycle weighting factors
for use in the twelve regulatory classes or ten model categories. Table 4-5 shows that these
weightings are specific to sleeper cab (long distance, typically >500 miles cruising), day cab
(<~100 miles cruising), and vocational trucks (stop and go operation).
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Draft Regulatory Impact Analysis
Table 4-5: Drive Cycle Weightings
DRIVE CYCLES &
WEIGHTINGS:
Transient
55 mph Cruise
65 mph Cruise
SLEEPER CAB
5%
9%
86%
DAY CAB
19%
17%
64%
VOCATIONAL
TRUCK
42%
21%
37%
Linking the pre- and post-processing functions to the MATLAB/Simulink/Stateflow-
based vehicle compliance model, a MATLAB-based Graphical User Interface (GUI) has also
been constructed. This GUI allows the user to select truck type, input required parameters and
look up the MATLAB/Simulink/Stateflow source models and script files. However, to ensure
the compliance model is not inadvertently modified during truck certification, EPA also
compiled a C-code based model and subsequently generated a stand-alone GUI-based executable
code which can be run with no MATLAB/Simulink/Stateflow licensing requirement. Upon
providing all the information requested by this C-code based model and stand-alone GUI, the
manufacturer then clicks "RUN" after which all their selections and entries are fed into the
EPA/NHTSA compliance model without the user ever directly interacting with the underlying
model source codes, built-in parameters, engine maps, etc. Figure 4-1 shows the GUI with ten
model categories. It is flexible and easy to use for certification of heavy-duty vehicles in any of
the twelve regulatory classes.
BH Greenhouse gas Emissions Model (GEM) v1.0
Greenhouse gas Emissions Model (GEM) vl.O
Identification
Manufacturer Name
VERIFY User ID:
Vehicle Family:
Engine Family:
E-mail Address:
VERIFY ID:
Vehicle Sub Family: f
Engine Sub Family: i
(Date)
Vehicle Model Year:
Engine Model Year:
Regulatory Class
O Class 8 Combination - Sleeper Cab - High Roof
O Class 6 Combination - Sleeper Cab • Mid Roof
O Class 6 Combination - Sleeper Cab • Low Roof
O Class 8 Combination • Day Cab - High Roof
O Class 8 Combination - Day Cab - Low/Mid Roof
O Class 7 Combination - Day Cab - High Roof
O Class 7 Combination - Day Cab - Low/Mid Roof
O Heavy Heavy-Duty - Vocational Truck (Class 8)
O Medium Heavy-Duty - Vocational Truck (Class 6-7)
O Light Heavy-Duty - Vocational Truck (Class 2b-5)
Simulation Inputs
Coefficient of Aerodynamic Drag
Steer Tire Rolling Resistance (kg/metric ton]
Drive Tire Rolling Resistance (kg/metric ton]
Vehicle Speed Limiter [mph]
Vehicle Weight Reduction [Ibs]
Extended Idle Reduction [gram C02/ton-mile]
!
'"I
Figure 4-1: Graphical User Interface (GUI)
4-8
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
4.4.2 Standardized Model with Same Default Input Parameters for Each Truck
Subcategory
With respect to combination tractors, as discussed in Chapter 2 of this DRIA, EPA and
NHTSA have identified many possible technologies which can achieve GHG emissions and fuel
consumption benefits for Class 7/8 combination tractors. However, as noted in the preamble to
the proposed rule, some technologies may not be suited for some combination trucks' usage
patterns. Others may be too complex to model. For example, it may be difficult to accurately
model those improvements which are based on each manufacturer's proprietary control
strategies. In developing a certification regime for the MY 2014-2017 period using GEM, EPA
and NHTSA are proposing three input parameters plus up to three adjustments to be used in the
combination truck simulation models (see section 4.5.1). Potential improvements which are not
proposed as part of the GEM model may be evaluated as a potential off-cycle credit opportunity.
For Class 2b to Class 8 vocational vehicles, the myriad vehicle types on the road today
make it challenging to group them into manageable categories for compliance purposes. For
reasons explained in Sections II and III of the preamble to the proposed rule, the agencies are
proposing standards which reflect use of improved tire rolling resistance, along with improved
engine performance. The only input to GEM would be tire rolling resistance (see section 4.4.4
below). Most of these trucks operate predominantly in an urban setting with transient (stop-and-
go) rather than steady state operation. Improvements in vocational vehicle aerodynamic features
are likely to generate little GHG emissions and fuel consumption benefits compared to those for
combination tractors whose operation are often at high and continuous cruising speeds. On the
other hand, advanced technologies such as hybrid systems are likely to result in greater fuel
economy benefits for these vocational truck classes as these technologies have been shown to
improve fuel efficiency for stop and go operations.14 Therefore, the agencies' proposed rule
seeks to encourage the production of hybrid systems for these vocational vehicles by means of
credit opportunities, where vehicle performance for GHG emissions and fuel consumption would
be assessed using test procedures outlined in Chapter 3 of this DRIA. For non-hybrid
conventional vocational trucks, EPA and NHTSA have grouped vocational trucks into three
separate classes based on their shared attributes: light-heavy (LH), medium-heavy (MH), and
heavy-heavy (HH), reflecting Classes 2b, 3, 4, or 5, Classes 6 or 7, and Class 8, respectively.
4.4.3 List of Required Truck-Specific Input Parameters for Class 7/8
Combination Tractor Models
The Class 7/8 combination tractor models developed by the agencies assume each Class
7/8 tractor is combined with a specific type of trailer that best matches the certifying tractor roof
height. Combination tractors belonging to any of the nine regulatory classes are to be certified
under seven model categories, i.e., two Class 7 day cab, three Class 8 sleeper cab, and two Class
8 day cab truck models. Manufacturers are required to provide EPA and NHTSA with the
following input parameters for certification:
1. Aerodynamic drag coefficient (Cd) per the assigned aerodynamic bin
2. Steer tire rolling resistance coefficient (Crr, steer tires)
4-9
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Draft Regulatory Impact Analysis
3. Drive tire rolling resistance coefficient (Crr, drive tires)
4. Weight reductions through lower weight wheels and tires
5. Governed vehicle speed, if less than 65 mph
6. Idle reduction technology, if any, for Class 8 sleeper tractors only
The manufacturers would be required to conduct appropriate testing to develop these
inputs using the procedures described in Chapter 3 and Preamble Section 2 for Cd and Crr for
both steer and drive tires.
4.4.4 List of Required Truck-Specific Input Parameters for Class 2b-8
Vocational Vehicle Models
For Class 2b to 8 vocational vehicles, the manufacturers would be required to provide
EPA and NHTSA with the same set of parameters as those required for combination tractors
except items #1, # 4, #5 and #6 for certification. Items #2 and #3 are required for certification.
(As noted in section 4.4.6, the agencies also plan to use predefined, standardized Cd for the three
vocational truck types (Vocational Light-Heavy (VLH), Vocational Medium-Heavy (VMH), and
Vocational Heavy-Heavy (VHH).)
4.4.5 List of Default Input Parameters for Class 7/8 Combination Truck Models
Though many technologies can potentially achieve GHG emission and fuel consumption
reductions, EPA and NHTSA realize that for the proposed timeframe, some may be too complex
to model (e.g., hybrid control) while others require standardization. For example, the calculation
of GHG and fuel consumption benefits due to aerodynamic improvements is coupled with truck
frontal area. To better capture the GHG emission and fuel consumption benefits in the
simulation model as well as to avoid unintended consequences in the real world, the agencies
have identified a set of parameters that are consistent across various manufacturers for this
rulemaking period and are proposing that these parameters be used as default inputs to the
model. EPA and NHTSA propose to standardize the truck frontal area, truck total and payload
weight, gear box and its efficiency, final drive ratio, engine/transmission/wheel inertia, accessory
load, axle base, tire radius, trailer tire coefficient of rolling resistance (Crr, trailer tires), and
engine fuel map. The agencies are proposing to use these standardized input parameters in the
simulation model for all seven model categories of combination trucks. Table 4-6 lists the
specific values of these parameters, which were developed using EPA test data, manufacturer
supplied information, and/or literature search.10'13
4-10
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
Table 4-6: Combination Truck Modeling Input Parameters
MODEL TYPE
Regulatory
Subcategory
Fuel Map
Gearbox
Gearbox Ratio
Gearbox
Efficiency
Engine Inertia
(kg-m2)
Transmission
Inertia (kg-m2)
All Axle Inertia
(kg-m2)
Loaded Tire
Radius (m)
Body Mass (kg)
Cargo Mass (kg)
Total weight (kg)
Total weight (Ibs)
Frontal Area (m2)
Drag Coefficient
Axle Base
Electrical
Accessory Power
Mechanical
Accessory Power
(W)
Final Drive Ratio
Tire CRR
(kg/ton)
Trailer Tire CRR
(kg/ton)
Steer Tire CRR
Drive Tire CRR
Vehicle Speed
Li miter
CLASS 8
Sleeper Cab
High Roof
10 speed
Manual
14.*
0.
4.17
0.2
300
0.4892
14742
17236
31978
70500
9.8
OEM Input
5
360
1000
2.64
6
OEM Input
OEM Input
OEM Input
CLASS 8
Sleeper Cab
Mid Roof
10 speed
Manual
5, 10.95, 8.09, £
96 0.96 0.96 0.
4.17
0.2
300
0.4892
13041
17236
30277
66750
7.7
OEM Input
5
360
1000
2.64
= 0.425
6
OEM Input
OEM Input
OEM Input
CLASS 8
Sleeper Cab
Low Roof
15L-455HP
10 speed
Manual
.97, 4.46, 3.32
96 0.980. 98 0.<
4.17
0.2
300
0.4892
13154
17236
30391
67000
6
OEM Input
5
360
1000
2.64
x Trailer CRR +
6
OEM Input
OEM Input
OEM Input
CLASS 8
Day Cab
High Roof
10 speed
Manual
2.45, 1.81, 1.
38 0.98 0.98 0
4.17
0.2
300
0.4892
14061
17236
31298
69000
9.8
OEM Input
5
360
1000
2.64
0.425 x Drive
6
OEM Input
OEM Input
OEM Input
CLASS 8
Day Cab
Low/Mid Roof
10 speed
Manual
35, 1
98
4.17
0.2
300
0.4892
12474
17236
29710
65500
6
OEM Input
5
360
1000
2.64
CRR + 0.15 x st
6
OEM Input
OEM Input
OEM Input
CLASS 7
Day Cab
High Roof
11L-
10 speed
Manual
11.06, 8. 1<
3.34, 2.48,
0
0.96 0.96 0
0.98 0.98 0
3.36
0.2
240
0.4892
11340
11340
22680
50000
9.8
OEM Input
4
360
1000
3.73
eerCRR
6
OEM Input
OEM Input
OEM Input
CLASS 7
Day Cab
Low/Mid Roof
350 HP
10 speed
Manual
3, 6.05, 4.46,
1.83, 1.36, 1,
.75
.96 0.96 0.98
.980.980.98
3.36
0.2
240
0.4892
9752
11340
21092
46500
6
OEM Input
4
360
1000
3.73
6
OEM Input
OEM Input
OEM Input
4-11
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Draft Regulatory Impact Analysis
Frontal Area - For Class 8 sleeper cabs, the frontal areas for high-, mid-, and low-roof
tractors were estimated to be 9.8, 7.7 and 6 square meters, respectively. For either a Class 7 or
Class 8 day cab, the frontal areas are assumed to be 9.8 and 6 square meters for high- and
low/mid-roof tractors, respectively. These values were developed from actual frontal area
measurements conducted for EPA by Automotive Testing and Development Services, Inc. based
in California.10
Truck Weight - It is assumed that the empty weight will vary by cab configuration and a
standard weight for each category has been developed. For Class 8 trucks, the total weight
ranges from 65,500 to 70,500 Ibs, and for Class 7 trucks, 46,500 to 50,000 Ibs. The payload
capacity is assumed to be 19 and 12.5 tons for Class 8 and Class 7 trucks, respectively. The
development of the truck weights are discussed in DRIA Chapter 3.5.
Gear Box and Efficiency - The typical Class 8 and Class 7 combination tractors have 10
speed manual transmissions. The respective gear ratios for Class 8 and Class 7 combination
tractors are: 14.8, 10.95, 8.09, 5.97, 4.46, 3.32, 2.45, 1.81, 1.35, 1 and 11.06, 8.19, 6.05, 4.46,
3.34, 2.48, 1.83, 1.36, 1, 0.75. The agencies based the gear ratios on the actual tractors tested at
Southwest Research Institute.13 The same set of efficiencies is utilized for each of these models,
ranging from 0.96 to 0.98. The efficiencies were based on an engineering judgment of the
agencies.
Final Drive Ratio - As above, a typical configuration is a 10 speed manual transmission
with a final drive ratio of approximately 2.64 and 3.73 for Class 8 and Class 7 tractors,
respectively. The agencies based the final drive ratios on the actual tractors tested at Southwest
Research Institute.1
Inertia - The agencies are proposing that the engine inertia for Class 7 and Class 8
tractors are taken to be 3.36 and 4.17 kg-m , respectively based on the agencies' engineering
judgment. The transmission inertia for all combination tractors is 0.2 kg-m2 and the axle inertia
for Class 8 and Class 7 tractors are 300 and 240 kg-m2, respectively. The axle inertia values are
based on agencies' engineering judgment of the actual rotational inertia measured for a Class 8
sleeper cab at SwRI.15
Accessory Load - It is assumed that all combination tractors carry an electrical load of
360 watts and a mechanical load of 1,000 watts.
Axle Base - Typical Class 8 tractors have 1 steer and 2 drive axles, while typical Class 7
tractors have 1 steer and 1 drive axle. The trailer used for both Class 7 and Class 8 cabs in
simulation modeling has 2 axles.10'13
Tire Radius - The static loaded tire radius for all combination trucks would be 489 mm
(or 515 mm, unloaded). The value is based on the actual tires used during the Southwest
Research Institute testing.13
Trailer Tire Coefficient of Rolling Resistance (Crr, trailer tires) - The agencies assume
6.0 kg/ton for all trailer tires. This value was developed through the SmartWay tire testing.16
4-12
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
Engine Fuel Map - The agencies developed two sets of representative engine maps which
are to be used by manufacturers for modeling combination and vocational truck GHG emissions
and fuel consumption. The first set would be used for 2014-16 model years and represents
engines which meet the proposed main 2014 MY engine standard (not the proposed alternative
standard). The second set would be used by truck manufacturers for 2017 model year and later
compliance where the fuel maps represent engines which meet the proposed 2017 model year
engine standard. Each set consists of two separate maps, a 455 hp @ 1800 rpm (15 liter engine)
and 350 hp @ 1800 rpm (11 liter engine), which would be used for certification of Class 8 and
Class 7 combination tractors. The process for engine fuel map development is described as
follows.
Each of these projected maps is created by merging 2007-2009 model year heavy-duty
engine data supplied by the heavy-duty manufacturers with those collected at the EPA test site
via engine dynamometer testing, as per 40 CFR Part 1065.17 The process of map generation is
iterative and many factors are considered during data aggregation to ensure that the resulting,
pre-2010 model year engine maps are consistent with those of the respective heavy-duty engine
ratings sold in today's market. These pre-2010 maps are subsequently adjusted to represent 2010
model year engine maps by using predefined technologies including SCR and other advanced
systems that are being used in current 2010 production. These 2010 engine maps are further
transformed into 2014 engine maps by considering many potential technologies that could be
used in the 2014 timeframe. These include, but not limited to, further reductions in parasitic and
friction losses, more advanced combustion, and progressively higher efficient air/EGR handling
and aftertreatment systems - the technology package on which the proposed 2014 MY engine
standards is premised.. Lastly, the 2017 model year fuel maps are developed with a similar
method used for generating 2014 model year maps, but with more aggressive improvements
using the technology package on which the proposed MY 2017 standards are premised (i.e.
addition of turbocompounding to the MY 2014 technology package). Details of the evaluation
process by which the technologies can reduce engine CO2 emissions or fuel consumption are
discussed in Chapter 2 of this DRIA.
A typical engine fuel map consists of three columns - engine speed, torque, and fueling
rate in gram per second. Table 4-7 shows a small subset of a representative engine map in such a
format. Essentially, the fueling rate is a function of engine speeds and loads. Displayed in
Figure 4-2 is an example of the fueling rate contour as function of engine torque and speed for a
Class 8 combination tractor with 455 hp rating. This map can be further processed to obtain
other key engine performance information, such as brake specific fuel consumption (BSFC), as
shown in Figure 4-3.
4-13
-------
Draft Regulatory Impact Analysis
Table 4-7: A Small Subset of Fuel Map Input
SET
MODE
Idle
A100
B50
B75
A50
A75
A25
B100
B25
C100
C25
C75
C50
SPEED
(RPM)
600
1233
1514
1514
1233
1233
1233
1514
1514
1796
1796
1796
1796
TORQUE
(NM)
0
2100
1040
1559
1050
1575
525
2079
520
1805
451
1354
903
FUEL RATE
(g/s)
0.04
14.77
9.36
13.72
7.43
10.78
4.26
18.38
5.68
19.71
6.94
14.86
10.48
455 HP /15 L : 2010 Baseline Fuel Rate (g/s)
300 800
1000 1200 1400 1600
Engine Speed (RPM)
1800 2000
Figure 4-2: Fueling Rate (g/s) as a Function of Engine Torque and Speed for a Combination Tractor
4-14
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
2200
2000
455 HP/15 L : 2010 Baseline BSFC (g/kW-hr)
300 800 1000 1200 1400 1600 1800 2000
Engine Speed (RPM)
Figure 4-3: Class 8 Engine BSFC Map
4.4.6 List of Default Input Parameters for Class 2b-8 Vocational Vehicle Models
Likewise, EPA and NHTSA propose to standardize a set of parameters for the three Class
2b-8 vocational vehicle types, which the agencies refer to as Vocational Light-Heavy (VLH),
Vocational Medium-Heavy (VMH), and Vocational Heavy-Heavy (VHH). These default
parameters include the coefficient of aerodynamic drag, truck frontal area, truck total and
payload weight, the gear box and its efficiency, final drive ratio, engine/transmission/wheel
inertia, accessory load, axle base, tire radius, and the engine fuel map. Standardized input
parameters to be used in the simulation model for all three vocational trucks have been
developed using a combination of EPA test data, manufacturer supplied information, and/or
literature search. The specific values of these parameters are listed in Table 4-8.
Coefficient of Aerodynamic Drag (Cd) - A Cd of 0.6 for both VLH and VMH models
and 0.7 for VHH, is adopted.
Frontal Area - For both VLH and VMH truck models, the frontal area is assumed to be 9
square meters, and for the VHH model 9.8 square meters based on the agencies' estimates from
the combination tractor frontal area measurements.10
Truck Weight - The total weight is established at 16,000, 25,150, and 67,000 Ibs for
VLH, VMH, and VHH models and the payload is 2.85, 5.6 and 19 tons, respectively, for VLH,
VMH and VHH truck models.18
4-15
-------
Draft Regulatory Impact Analysis
Gear Box and Efficiency - A 10 speed manual transmission is adopted in the VHH truck
model with gear ratios at: 14.8, 10.95,8.09,5.97,4.46,3.32,2.45, 1.81, 1.35, 1. A six speed
manual transmission is utilized for both VLH and VMH truck models with respective gear ratios
of: 9.01, 5.27, 3.22, 2.04, 1.36, 1. Gear efficiencies of the 6 speed manual transmission range from
0.92 to 0.95.
Final Drive Ratio - The final drive ratios are 3.25, 3.36, and 2.64 (the actual final drive
ratio for Truck 555) for the VLH, VMH, and VHH truck models, respectively. The VLH and
VMH final drive ratios are selected based on using powertrain selection tool 9 and agencies'
engineering judgment.
Inertia - For VHH, it is assumed the same engine and transmission inertia values as those
used for a Class 8 combination tractor, while the axle inertia is 168 kg-m2. For both the VLH
and VMH truck models, the engine, transmission and axle inertia values are 2.79, 0.1 and 90 kg-
9 ic
m , respectively.
Accessory Load - It is estimated that all vocational trucks carry an electrical load of 360
watts and a mechanical load of 1,000 watts.
Axle Base - It is assumed that both the VLH and VMH models have 1 steer and 1 drive
axle, while the VHH trucks have 1 steer and 2 drive axles based on typical configurations found
in use.
Tire Radius - The static loaded tire radii for VLH, VMH, and VHH trucks are 381, 395,
and 489 mm, respectively.
Engine Fuel Map - In addition to the two sets of Class 7 and Class 8 combination tractor
engine maps, two sets of engine maps have been created which would be used by manufacturers
for modeling LH and MH vocational truck GHG emissions. The map created for use in Class 8
combination truck models (455 hp @ 1800 rpm) would also be used for the Vocational Heavy-
Heavy truck model. Two sets of LH and MH engine maps, a 200 hp @ 2000 rpm (7 liter engine)
and 270 hp @ 2200 rpm (also 7 liter engine), would be used by manufacturers for certification of
LH and MH vocational trucks in 2014-16 and in 2017, respectively.
The same methodology used for generating representative 2014 and 2017 Class 7 and
Class 8 engine maps was also used for vocational truck engine map development. Figure 4-4
shows an example of the fueling rate contour as a function of engine torque and speed for a
vocational truck with 270 hp rating.
4-16
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
Table 4-8: Vocational Truck Modeling Input Parameters
Model Type
Regulatory
Subcategory
Fuel Map
Gearbox
Gearbox Ratio
Gearbox Efficiency
Engine Inertia (kg-rn^)
Transmission Inertia
(kg-m2)
All Axle Inertia (kg-rn^)
Loaded Tire Radius (m)
Body Mass (kg)
Cargo Mass (kg)
Total weight (kg)
Total weight (Ibs)
Frontal Area (m^)
Drag Coefficient
Axle Base
Electrical Accessory
Power (W)
Mechanical Accessory
Power (W)
Final Drive Ratio
Tire CRR
(kg/ton)
Trailer Tire CRR
(kg/ton)
Steer Tire CRR
Drive Tire CRR
Heavy Heavy-Duty
Vocation Truck
(Class 8)
15L-455HP
10 speed Manual
14.8, 10.95, 8.09,5.97,4.46,
3.32,2.45, 1.81, 1.35, 1
0.96 0.96 0.96 0.96 0.98
0.980.980.980.980.98
4.17
0.2
168
0.4892
13154
17236
30391
67000
9.8
0.7
3
360
1000
2.64
Medium Heavy-Duty
Vocation Truck
(Class 6-7)
7L-270HP
6 speed Manual
9.01,5.27,3.22,
2.04, 1.36, 1
0.920.920.930.95
0.95 0.95
2.79
0.1
90
0.395
6328
5080
11408
25150
9
0.6
2
360
1000
3.36
Light Heavy-Duty
Vocation Truck
(Class 2b-5)
7L-200HP
6 speed Manual
9.01,5.27,3.22,
2.04, 1.36, 1
0.920.920.930.95
0.95 0.95
2.79
0.1
90
0.381
4672
2585
7257
16000
9
0.6
2
360
1000
3.25
= 0.5 x Drive CRR + 0.5 x steer CRR
Not applicable Not applicable Not applicable
OEM Input OEM Input OEM Input
OEM Input OEM Input OEM Input
4-17
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Draft Regulatory Impact Analysis
270 HP / 7 L : 2010 Baseline Fuel Rate (g/s)
900 —
800 1000 1200 1400 1600 1800 2000 2200 2400 2600
Engine Speed (RPM)
Figure 4-4: Fueling Rate (g/s) as a Function of Engine Torque and Speed for a Vocational Truck
4.5 Application of Model for Certification
The agencies are proposing that vehicle manufacturers demonstrate truck compliance
using GEM for the following vehicle types.
• Class 7/8 Combination Tractors: Manufacturers use one of seven predefined
combination truck models to generate GHG emissions and fuel consumption.
• Class 2b-8 Vocational Vehicles: Manufacturers use one of three predefined
vocational vehicle models to generate GHG emissions and fuel consumption.
4.5.1 Class 7/8 Combination Tractors - Use One of Seven Applicable
Combination Truck Models
As mentioned previously, EPA and NHTSA have defined three required input parameters
and up to three allowable adjustments, the adjustments reflecting additional use of weight
reduction, use of vehicle speed limiters, and/or use of idle reduction technologies. These
parameters would be input to the simulation model to generate cycle-weighted GHG emissions
4-18
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
and fuel consumption for certification. For Class 7/8 combination tractor certification, the
manufacturer would provide this information to the agencies in the graphical user interface.
For example, if the manufacturer plans to produce a Class 7 or 8 combination tractor in
2014 to 2017, appropriate testing would be conducted by the manufacturer to assess the vehicle
aerodynamics and rolling features as per test procedures described in Chapter 3 of this DRIA and
Preamble Section 2. For steer and drive tire rolling friction assessment, the manufacturer would
either conduct its own testing or obtain applicable test results from the tire manufacturer. The
vehicle manufacturer needs to document the source of these test data for Cd and Crr (steer and
drive tires) as part of the certification process.
If applicable, the vehicle manufacturer would further input specific values reflecting use
of: (1) restricting the top speed of the vehicle to below 65 mph (2) reducing the tire weight to be
less than the EPA-default body mass, and (3) installing special features on the vehicle to reduce
extended idle (applicable to sleeper cabs only).
The quantification procedure to certify truck GHG emissions and fuel consumption using
these adjustments are the following:
Vehicle Speed Limiter (VSL) - If the manufacturer limits the vehicle in-use top speed to
below 65 mph with a Vehicle Speed Limiter device, a cycle reflecting the vehicle top speed shall
be substituted for the 65 mph drive cycle for quantifying GHG emissions and fuel consumption
over the high speed cruising cycle.
Weight Reduction - If the manufacturer uses alternate material for wheels and/or installs
single wide tires in lieu of duals, it is very likely that the empty weight of the certifying Class 7/8
tractor body mass is less than that listed in Table 4-5. Therefore, the manufacturer would be
allowed to apply adjustments to the vehicle GHG emissions and fuel consumption calculation by
reporting the difference between the EPA/NHTSA-defmed tractor mass and the actual body
mass. This adjustment is applied during the post-processing GHG emissions and fuel
consumption calculation, in which one third of the mass reduction is added to the defined
payload. This would essentially increase the denominator, i.e., payload, for all three cycle
outputs, resulting in less overall gram CCVton-mile emissions or gallon/ton-mile fuel
consumption.
Extended Idle Reduction Technology (applicable only to Class 8 sleeper cabs) - If the
combination tractor is equipped with an extended idle reduction technology and an Automatic
Engine Shutoff system, then the manufacturer would be allowed to select idle reduction in GEM
which provides a 5 grams/ton-mile GHG emissions reduction (and equivalent fuel consumption
reduction) from the cycle-weighted GHG emissions and fuel consumption. Table 4-9 lists some
examples of these extended idle reduction technologies.
4-19
-------
Draft Regulatory Impact Analysis
Table 4-9: Examples of Extended Idle Reduction Technologies
Automatic Engine Shutoff Only
Auxiliary Power Unit + Shutoff
Fuel Operated Heater + Shutoff
Thermal Storage Unit + Shutoff
Battery Air Conditioner + Shutoff
Truck Stop Electrification + Shutoff
4.5.2
Class 2b-8 Vocational Vehicles - Use One of Three Applicable Vocational
Truck Models
For Class 2b-8 vocational vehicle certification in the 2014-2017 MY timeframe, the
manufacturer would conduct appropriate testing to assess the tire rolling features as per test
procedures described in Chapter 3 and Preamble Section 2. The process for tire rolling friction
assessment is identical to that required for combination tractors, i.e. the manufacturer shall either
conduct its own testing or obtain appropriate test results from the tire manufacturer. The vehicle
manufacturer needs to document the source of these test data, i.e., Crr as part of the certification
process.
The adjustments available to Class 7/8 combination tractors for reducing GHG emissions
and fuel consumption are not applicable to any of the vocational truck classes so that any further
improvements in performance would be considered (potentially) as an off-cycle credit or
advanced technology credit and would not be evaluated using the GEM model.
4-20
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Simulation Model
References
1 SAE International, Joint TMC/SAE Fuel consumption test procedure - Type II, SAE Surface Vehicle
Recommended practice J1321, 1986
2 Title 40 United States Code of Federal Regulations, Part 86 Subpart B, § 86.127 Test Procedures; Overview, 2010.
3 Title 40 United States Code of Federal Regulations, Part 86 Subpart N, § 86.1327 Engine Dynamometer Test
Procedures; Overview, 2010.
4http://www.transportation.anl.gov/modeling_simulation/PSAT/tech_info.html.
5 http://www.carsim.com/products/trucksim/index.php.
6 "Simulink® 7 Simulation and Model-Based Design," 9320v06_Simulink7_v7.pdf, The MathWorks, September
2007.
7 http://www.mathworks.com/products/matlab © 1994-2010 The MathWorks, Inc.
8 http://www.mathworks.com/products/simulink © 1994-2010 The MathWorks, Inc.
9 http://www.mathworks.com/products/stateflow © 1994-2010 The MathWorks, Inc.
10 US EPA. Heavy-Duty Coastdown Test Procedure Development. Docket # EPA-HQ-OAR-2010-0162-0144.
11 US EPA. Heavy-Duty Greenhouse Gas and Fuel Consumption Test Program Summary. Docket # EPA-HQ-
OAR-2010-0162.
12 http://gtisoft.eom/applications/a Vehicle driveline.php.
13 Southwest Research Institute Final Report (in preparation) for EPA Contract BPA 08-01 Task Order 1103.
14 Christenson, M. and Greuel, J., Evaluation of the Proposed Smart Way Fuel Efficiency Test Protocol for Medium-
and Heavy-duty Vehicles, Report A: Conventional and Hybrid Utility Trucks, ERMS Report No. 08-38, 2009.
15 "Rotational Inertia Measurement and Estimation of Heavy-Duty Vehicle Wheel Sets," Southwest Research
Institute Report (in preparation) for EPA Contract BPA 08-01 Task Order 1103.
16 United States Environmental Protection Agency. SmartWay Transport Partnership July 2010 e-update accessed
July 16, 2010, from http://www.epa.gov/smartwavlogistics/newsroom/documents/e-update-julv-10.pdf
17 Title 40 United States Code of Federal Regulations, Part 1065 Subpart F, §1065.510 Engine Mapping, 2010.
18 "Greenhouse Gas Management for Medium-Duty Truck Fleets, A Framework for Improving Efficiency and
Reducing Emissions," 10860-fleets-med-ghg-management.pdf, http://phharval.com.
19
http://www.powerspec.cummins.com/site/home/index.html
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Emissions Inventory
CHAPTER: 5 Emissions Impacts
5.1 Executive Summary
Climate change is widely viewed as the most significant long-term threat to the global
environment. According to the Intergovernmental Panel on Climate Change, anthropogenic
emissions of greenhouse gases (GHG) are very likely (90 to 99 percent probability) the cause of
most of the observed global warming over the last 50 years. The primary GHGs of concern are
carbon dioxide (CO2), methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur
hexafluoride.l Mobile sources emitted 31 percent of all U.S. GHG in 2007 (transportation
sources, which do not include certain off-highway sources, account for 28 percent) and have
been the fastest-growing source of U.S. GHG since 1990.2 Mobile sources addressed in the
recent endangerment finding under CAA section 202(a)~light-duty vehicles, heavy-duty trucks,
buses, and motorcycles—accounted for 23 percent of all U.S. GHG in 2007.3 Heavy-duty
vehicles emit CC>2, methane, nitrous oxide, and hydrofluorocarbons and are responsible for
nearly 19 percent of all mobile source GHGs (nearly 6% of all U.S. GHGs) and about 25 percent
of Section 202(a) mobile source GHGs. For heavy-duty vehicles in 2007, CC>2 emissions
represented more than 99 percent of all GHG emissions (including HFCs).
This proposal estimates anticipated impacts from the EPA vehicle CC>2 emission
standards. The emissions from the GHGs carbon dioxide (CO2), methane (CH/i), nitrous oxide
(N2O) and hydrofluorocarbons (HFCs) were quantified. In addition to reducing the emissions of
greenhouse gases, this proposal would also influence the emissions of "criteria" air pollutants,
including carbon monoxide (CO), fine particulate matter (PM2.s) and sulfur dioxide (SOx) and
the ozone precursors hydrocarbons (VOC) and oxides of nitrogen (NOx); and several air toxics
(including benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and acrolein).
Downstream (tailpipe) emission impacts were developed using EPA's Motor Vehicle
Emission Simulator (MOVES2010). Upstream (fuel production and distribution) emission
changes resulting from the decreased fuel consumption predicted by the downstream models
were calculated using a spreadsheet model based on emission factors from GREET.4 Based on
these analyses, this proposal would lead to 72 million metric tons (MMT) of CC>2 equivalent
(CC^EQ) of annual GHG reduction and 5.8 billion gallons of fuel savings in the year 2030.
The non-GHG impacts the proposal are driven by the increased use of auxiliary power units
(APUs) and reduced emissions from upstream fuel production and distribution. Emissions of
certain pollutants are further reduced through improved aerodynamics and tire rolling resistance.
To a much smaller extent, rebound of vehicle miles traveled (VMT) increases emissions of all
pollutants proportional to the VMT rebound amount. Table 5-1 summarizes these non-GHG
emissions impacts.
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Draft Regulatory Impact Analysis
Table 5-1 Impacts of Program on Non-GHG Emissions (Short Tons per year)
POLLUTANT
A 1,3 -Butadiene
A Acetaldehyde
A Acrolein
A Benzene
A Carbon Monoxide
A Formaldehyde
A Oxides of Nitrogen
A Paniculate Matter
(below 2.5 micrometers)
A Oxides of Sulfur
A Volatile Organic Compounds
CALENDAR
YEAR
2030
-1
-1,903
-262
-358
-56,923
-6,252
-241,254
363
-6.650
-29,540
CHANGE VS.
2030
BASELINE
-0.1%
-37.8%
-37.7%
-13.0%
-2.1%
-44.0%
-19.6%
0.98%
-9.3%
-14.8%
5.2 Introduction
5.2.1 Scope of Analysis
The proposed standards affect both diesel- and gasoline-fueled heavy-duty vehicles. This
analysis accounts for the direct downstream/tailpipe reduction of GHG as well upstream (fuel
production and distribution) reductions of GHGs and non-GHGs. Total GHG impacts will also
be determined by any VMT rebound effects, changes in fleet turnover, and changes in fuel
consumption globally due to reduced petroleum prices. See Chapter 9 for a further discussion of
these aspects of the analysis. The agencies also expect this proposal to impact downstream and
upstream emissions of non-GHG air pollutants.
Emissions estimates for the four greenhouse gases carbon dioxide (CO2), methane (CH4),
nitrous oxide (N2O), and hydrofluorocarbons (HFC) are presented herein. Inventories for the
non-GHG pollutants 1,3-butadiene, acetaldehyde, acrolein, benzene, carbon monoxide (CO),
formaldehyde, oxides of nitrogen (NOx), particulate matter below 2.5 micrometers (PM2.s),
oxides of sulfur (SOx), and volatile organic compounds (VOC) are also presented.
5.2.2 Downstream Contributions
The largest source of GHG and other air pollutant reductions from this proposal is from
tailpipe emissions produced during vehicle operation. Absolute reductions from tailpipe
emissions are projected to grow over time as the fleet turns over to vehicles affected by the
standards, meaning the benefit of the program will continue to grow as long as the older vehicles
in the fleet are replaced by newer, lower CO2-emitting vehicles.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Emissions Inventory
As described herein, the downstream reductions in emissions due to the program are
anticipated to be achieved through improvements in engine efficiency, road load reduction, and
APU use during extended idling.
Changes in downstream GHG and other emissions at the fleet level will be affected by
whether the regulations affect the timing of fleet turnover and total VMT, as discussed in Section
8 of the preamble. If the regulations spur firms to increase their purchase of new vehicles before
efficiency standards are in place ("pre-buy") or to delay their purchases once the standards are in
place to avoid higher costs, then there will be a delay in achieving the full GHG and other
emission reductions from improved fuel economy across the fleet. If the lower per-mile costs
associated with higher fuel economy lead to an increase in VMT (the "rebound effect"), then
total emission reductions will also be reduced. Chapter 9 of this draft RIA provides more detail
on how the rebound effect is calculated in EPA's analysis. The analysis discussed in this chapter
incorporates the rebound effect into the estimates, though fleet turnover impacts are not
estimated.
In addition, EPA also recognizes that this proposed regulation would lower the world
price of oil (the "monopsony" effect, further discussed in Chapter 9 of the draft RIA). Lowering
oil prices could lead to an uptick in oil consumption globally, resulting in a corresponding
increase in GHG emissions in other countries. This global increase in emissions could slightly
offset some of the emission reductions achieved domestically as a result of the regulation. EPA
does not provide quantitative estimates of the impact of the proposed regulation on global
petroleum consumption and GHG emissions in this draft RIA.
5.2.3 Upstream Contributions
In addition to downstream emission reductions, reductions are expected in the emissions
associated with the processes involved in getting fuel to the pump, including the extraction and
transportation of crude oil, the production, and the distribution of finished gasoline and diesel.
Changes are anticipated in upstream emissions due to the expected reduction in the volume of
fuel consumed. Less fuel consumed means less fuel transported, less fuel refined, and less crude
oil extracted and transported to refineries. Thus, there should be reductions in the emissions
associated with each of these steps in the fuel production and distribution process. Any changes
in downstream reductions associated with changes in fleet turnover, VMT, and global petroleum
consumption should be reflected in a corresponding change in upstream emissions associated
with petroleum processing and distribution.
5.2.4 Global Warming Potentials
Throughout this document, in order to refer to the four inventoried greenhouse gases on an
equivalent basis, Global Warming Potentials (GWPs) are used. In simple terms, GWPs provide a
common basis with which to combine several gases with different heat trapping abilities into a
single inventory (Table 5-2). When expressed in CC>2 EQ terms, each gas is weighted by its heat
trapping ability relative to that of carbon dioxide. The GWPs used in this chapter are drawn
from publications by the Intergovernmental Panel on Climate Change (IPCC).5
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Draft Regulatory Impact Analysis
The global wanning potentials (GWP) used in this analysis are consistent with the 2007
Intergovernmental Panel on Climate Change (TPCC) Fourth Assessment Report (AR4). At this
time, the 1996 IPCC Second Assessment Report (SAR) global warming potential values have
been agreed upon as the official U.S. framework for addressing climate change and are used in
the official U.S. greenhouse gas inventory submission to the United Nations climate change
framework. This is consistent with the use of the SAR global warming potential values in
current international agreements.
Table 5-2 Global Warming Potentials for the Inventory GHGs
GAS
CO2
CH4
N2O
HFC
GLOBAL WARMING
POTENTIAL
(CO2 Equivalent)
1
25
298
1,430
5.3 Program Analysis and Modeling Methods
5.3.1 Models Used
The Motor Vehicle Emissions Simulator, more commonly called MOVES, EPA's official
mobile source emission inventory model, was the primary tool used to calculate downstream
emissions inventories.6 The 2009-December-21 version of MOVES was used along with the
2010-May-15 default database. Some post-processing was done to MOVES output to ensure
proper calculation of emissions inventories for each alternative.
This proposal affects heavy-duty vehicles. In MOVES, which categorizes vehicle types
by their use, these vehicle types are represented by combination tractors, single unit tractors,
refuse trucks, motor homes, transit buses, intercity buses, school buses, and light commercial
trucks. Changes made to the default MOVES data for the baseline and the control case are
described below in Section 5.3.2. All the input data and MOVES run spec files can be found in
the docket.7
Upstream emissions were calculated using the same tools as were used for the Renewable
Fuel Standard 2 (RFS2) rule analysis, but for the current analysis it was assumed that all impacts
are related to changes in volume of gasoline and diesel produced and consumed, with no changes
in volumes of ethanol or other renewable fuels such as biodiesel.8 This assumption is reasonable
because EISA mandates that a certain volume of renewable fuels be blended into the fuel supply,
regardless of the quantity of conventional liquid fuels consumed. The estimate of emissions
associated with production of gasoline and diesel from crude oil is based on emission factors in
the "Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation" model
(GREET) developed by DOE's Argonne National Lab, and are consistent with those used for the
Light-Duty Greenhouse Gas rulemaking.4'9 The actual calculation of the emission inventory
impacts of the decreased gasoline production is done in EPA's spreadsheet model for upstream
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Emissions Inventory
emission impacts. This model uses the decreased volumes of the crude based fuels and the
various crude production and transport emission factors from GREET to estimate the net
emissions impact of fuel use changes. As just noted, the analysis for this rulemaking assumes
that all changes in volumes of fuel used affect only gasoline and diesel, with no effects on use of
ethanol, or other renewable fuels.
5.3.2 Calculation of Downstream Emissions
5.3.2.1 Baseline (reference case)
The baseline, or reference case, assumes no action. Since MOVES2010 vehicle sales and
VMT inputs were developed from AEO2006, EPA first updated these data using sales and
activity estimates from AEO2010.10 EPA also updated the fuel supply information in MOVES
to reflect a 100% E10 "gasoline" fuel supply to reflect the Renewable Fuels Standard.u The
tables that were modified and included as user input tables for the baseline run were fuelsupply,
fuelformulation, sourcetypeyear, and hpmsvtypeyear. For HD pickups and vans, the agency
updated sales projections for model years 2011 through 2018 using forecasts purchased from
CSM Worldwide for the light-duty greenhouse gas rule.12 This update was done through
modifying the base population, along with the sales growth factors for model years 2011 through
2018, in the sourcetypeyear table. The sales growth factors for the other model years were
updated from AEO2010, as mentioned above. MOVES2010 defaults, including all emission
rates, were used for all other parameters to estimate the baseline emissions inventories. For
aerodynamic drag and tire rolling resistance coefficients, the default MOVES values represent a
fleet-wide average rolling resistance and aerodynamic drag (for each MOVES source/vehicle
type), which assumes only a low level of adoption, if any, of low rolling resistance tires and
advanced aerodynamic features. It also assumes that these fleet-wide coefficients do not change
with future model years or by age.
For extended idling emission inventories, MOVES defaults were post-processed to
account for increased use of auxiliary power units (APUs) for model year 2010 and later, which
is not assumed in default MOVES. For all alternatives, the agencies assumed that about 30
percent of all combination long-haul tractors between model years 2010 through 2013 use an
APU during extended idling. For alternatives where combination long-haul tractors are
regulated, the agencies assumed that 100 percent of those trucks model year 2014 and later use
APUs during extended idling. This assumption is based on the expectation that manufacturers
will use APUs to meet the vehicle GHG standard for combination long-haul tractors. For
alternatives where combination long-haul tractors are not regulated, the agencies assumed that 30
percent of those trucks model year 2014 and later use APUs during extended idling. A diesel
fuel consumption rate of 0.2 gallons per hour for APUs and a factor 10.180 kg CO2 per gallon
diesel were assumed. EPA also considered that diesel APUs are regulated as non-road small
engines for criteria (non-GHG) pollutants. Assuming that these APUs emit criteria pollutants at
the EPA standard, Table 5-3 shows the emission rate of APUs, given an extended idle load
demand of 4.5 kW (6 hp).13 For SO2, which is not regulated through engines, but rather through
fuel, the agency assumed a diesel fuel sulfur level of 15 ppm and a diesel fuel density of 6.9
Ib/gal. Total extended idle emissions were calculated by multiplying by the number of extended
idle hours by the emission rates in Table 5-3.
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Draft Regulatory Impact Analysis
Table 5-3 Estimated Emission Rates of non-GHG Pollutants from APUs
POLLUTANT
CO
NOX + NMHC
PM
S02
EMISSION RATE
[g/hr]
36
33.6a
1.8
0.0188
Note: aNOx rate was estimated to be 80% (26.88 g/hr), and NMHC (6.72 g/hr) was estimated to be 20%
of the total NOX+NMHC rate, based on the 2004 model year heavy-duty engine standard.14 VOC was
estimated to be equal to NMHC for this analysis.
5.3.2.2 Control Case/Proposal
This case represents the proposed rules. The fuel supply and sales updates implemented
in the baseline were also used in all the alternatives, including the control case, since this fuel
supply and sales projections are those for all future scenarios and are not affected by this
proposal. To account for improvements of engine and vehicle efficiency, EPA developed several
user inputs to run the alternatives in MOVES. Since MOVES does not calculate emissions based
on engine Federal Test Procedure (FTP) cycle results, EPA used the percent reduction in engine
CO2 emissions expected from the proposal to develop energy inputs for the control case runs.
Also, EPA used the percent reduction in aerodynamic drag coefficient and tire rolling resistance
coefficient expected from each alternative to develop road load inputs. Runs were post-
processed to calculate air toxics inventories for diesel vehicles and emissions and fuel
consumption from APUs.
5.3.2.2.1 Emission Rate and Road Load Inputs
Table 5-4 and Table 5-5 describe the estimated expected changes in engine emissions and
vehicle technologies from this proposal, which were input into MOVES for estimating control
case emissions inventories.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Emissions Inventory
Table 5-4 Estimated Reductions in Engine CO2 Emission Rates from this Proposal
GVWR CLASS
HHD (8a-8b)
MHD (6-7) and LHD 4-5
FUEL
Diesel
Diesel
Gasoline
MODEL
YEARS
2014-2016
2017+
2014-2016
2017+
2016+
CO2 REDUCTION
FROM BASELINE
3%
6%
5%
9%
5%
Table 5-5 Estimated Reductions in Rolling Resistance and Aerodynamic Drag Coefficients from Reference
Case for Alternative 6 (Model Years 2014 and Later)
TRUCK TYPE
Combination long-haul
Combination short-haul
Straight trucks, refuse trucks,
motor homes, transit buses,
and other vocational vehicles
REDUCTION IN TIRE
ROLLING RESISTANCE
COEFFICIENT FROM
BASELINE
8.4%
7.0%
10.0%
REDUCTION IN
AERODYNAMIC DRAG
COEFFICIENT FROM
BASELINE
7.2%
5.3%
0%
Since nearly all HD pickup trucks and vans will be certified on a chassis dynamometer,
the CO2 reductions for these vehicles will not be represented as engine and road load reduction
components, but total vehicle CO2 reductions. These estimated reductions are described in
Table 5-6.
Table 5-6 Estimated Total Vehicle CO2 Reductions for HD Pickup Trucks and Vans
GVWR
CLASS
LHD 2b-3
FUEL
Gasoline
Diesel
MODEL
YEARS
2014
2015
2016
2017
2018+
2014
2015
2016
2017
2018+
CO2 REDUCTION
FROM BASELINE
1.5%
2%
4%
6%
10%
2.3%
3%
6%
9%
15%
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Draft Regulatory Impact Analysis
Engine CC>2 reductions (Table 5-4) and HD pickup/van total vehicle CC>2 reductions
(Table 5-6) were modified in the emissionrate table in MOVES. The percentage reductions were
applied to the default energy rates. The improvements in tire rolling resistance and drag
coefficient were modified in the sourceusetype table. The percentage reductions were applied to
the road load coefficients. It was assumed that 100 percent of Class 7/8 combination long-haul
tractors model year 2014 and later use APUs during extended idling. Emissions from APUs in
the control case were calculated in the same way as the baseline (see Table 5-3)
5.5.2.2.2 VMTInputs
The HPMSVtype table was modified to reflect VMT rebound. This table contains VMT
growth factors from one calendar year to the next, starting from an absolute VMT estimate for
calendar year 1999. For the control case, we increased the HD pickup/van absolute VMT by
1.01%, the vocational vehicle absolute VMT by 0.68%, and the combination tractor absolute
VMT by 0.71% from baseline levels, based on the analysis in RIA Section 9.2. Since VMT
growth is by calendar year and not model year, to ensure that only model years affected by the
proposal experienced VMT rebound, the results from the baseline run were used in the control
case inventories for model years prior to the proposed rules' implementation.
5.3.2.2.3 Diesel Air Toxics Calculations
The composition of VOCs for heavy-duty diesel engines without model year 2007 and
later emission controls versus those engines with such controls vary significantly. Thus, EPA
developed one set of toxic to VOC ratios for pre-2007 diesel engines and another set for 2007
and later engines. Since light-duty diesels comprise a very small portion of the fleet, the same
ratios were applied to all diesel vehicle classes to streamline modeling.
EPA relied on a database compiled for the Coordinating Research Council (CRC E-75)
and National Renewable Energy Laboratory (NREL) to develop toxic to VOC ratios for pre-
2007 model year engines.15 This database was developed from a literature survey and included
data from 13 different studies. The studies included in this database were conducted in a number
of different countries, included heavy-duty and light-duty engines, a variety of diesel and
biodiesel fuels, and a number of different operating modes and cycles. The methodology they
used to develop ratios is described in detail in their technical report. Data from tests using non-
conventional diesel fuel (Fischer-Tropsch, bioDiesel, ethanol-Diesel blends, emulsified fuel,
European blends, and other obvious research fuels) were excluded, as were data from non-heavy-
duty engines.
Toxic-to-VOC ratios for benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and
acrolein were developed by EPA from the CRC E-75 database. EPA relied on United States data
from heavy-duty diesel engines running on conventional diesel fuels, collected on test cycles
representative of real world operation. Some studies measured emissions over distance, while
other studies measure emissions relative to engine work. For studies which measured emissions
relative to distance, we calculated mean emissions per mile for toxics and VOC, then calculated
a ratio of toxics to VOC. For studies which measured emissions relative to engine work, we
calculated mean emissions per brake horsepower hour for toxics and VOC, then calculated a
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Emissions Inventory
second ratio of toxics to VOC. We then calculated a composite ratio using sample size to weight
the two ratios. The resulting ratios are provided in Table 5-7.
For model year 2007 and later heavy-duty diesels, advanced emission controls change the
composition of VOCs. For these engines, we relied on speciated emissions data from the
Advanced Collaborative Emissions Study (ACES), directed by the Health Effects Institute and
Coordinating Research Council, with participation from a range of government and private
sector sponsors.16 Detailed emissions data from the study were provided to EPA at the request
of the Coordinating Research Council. The data were collected on four engines on several test
cycles with low sulfur diesel fuel. EPA used data from a 16-hour transient cycle. Toxic to VOC
ratios obtained from the ACES data are provided in Table 5-7. Because diesel VOC estimates
had not been updated in MOVES for model year 2007 and later heavy-duty diesel trucks, these
data were also used to determine a VOC-to-total hydrocarbon (THC) ratio for those trucks. This
ratio of 0.5327 was used in conjunction with the MOVES results for THC to estimate VOC
emissions from model year 2007 and later heavy-duty diesel trucks.
All model year APUs were treated like pre-2007 engines with respect to toxics
calculations because APUs are not equipped with the emission controls technology of model
year 2007 and later engines.
Table 5-7 Air Toxics Ratios Post-Processed Against Hydrocarbon Results from MOVES
MODEL YEARS
Pre-2007 engines
and all model year
APUs
2007 and later
engines
POLLUTANT
Benzene
1,3 -butadiene
Formaldehyde
Acetaldehyde
Acrolein
Benzene
1,3 -butadiene
Formaldehyde
Acetaldehyde
Acrolein
RATIO to VOC
0.0078
0.0029
0.0782
0.0356
0.0066
0.0129
0.0008
0.2174
0.0693
0.0100
5.3.3 Calculation of Upstream Emissions
The term "upstream emissions" refers to air pollutant emissions generated from all crude
oil extraction, transport, refining, and finished fuel transport, storage, and distribution; this
includes all stages prior to the final filling of vehicle fuel tanks at retail service stations. The
details of the assumptions, data sources, and calculations that were used to estimate the emission
impacts presented here can be found in the Technical Support Document and the docket memo,
"Calculation of Upstream Emissions for the GHG Vehicle Rule", initially created for use in the
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Draft Regulatory Impact Analysis
Light-Duty Greenhouse Gas rulemaking.1? The results of this analysis are shown in Table 5-10
and Table 5-12.
5.3.4 Calculation of HFC EmissionsA
EPA is proposing to set air conditioning (AC) leakage standards for HD pickup trucks
and vans and combination tractors to reduce HFC emissions. The Vintaging Model, developed
by the EPA Office of Atmospheric programs, produces HFC inventories for several categories of
stationary and mobiles sources. However, it does not include air conditioning systems in
medium and heavy duty trucks within its inventory calculations. For this proposal, we conducted
a new analysis based on the inputs to the Vintaging Model and the inputs to the MOVES analysis
discussed in Chapter 5.3.2.1 above.
The general equation for calculating HFC emissions follows:
HFC emissionsyearx = AC Systemsyearx x Average Charge Size x HFC loss rate
We determined the number of functioning AC systems in each year based on the
projected sales of vehicles, the fraction of vehicles with AC systems, and the average lifetime of
an air conditioning system. Sales were drawn from the MOVES analysis and we assumed that
every vehicle had a functioning AC system when sold based on feedback received from truck
manufacturers. The Vintaging Model assumes that all light duty passenger vehicle AC systems
1 &
(in the U.S.) last exactly 12 years. For lack of better information, we assumed that heavy duty
vehicles AC systems last for the same period of time as light duty vehicles. Light, medium and
heavy duty vehicles use largely the same components in their air conditioning systems, which
would indicate similar periods of durability.
The charge size was determined using the Minnesota refrigerant leakage database.19
EPA sorted the data based on AC charge size and evaluated only the largest 25 percent of AC
systems. The average charge size is 1,025 grams of refrigerant.
Due to the similarity in system design, we assumed that the light-duty vehicle emission
rate in the Vintaging Model was applicable to the current analysis, as shown in Table 5-8. The
Vintaging Model assumes that losses occur from three events: leak, service, and disposal.
Although vehicle AC systems are serviced during discrete events and not usually every year,
emissions from those events are averaged over the lifetime of the AC system in the Vintaging
model. Leak and service emissions are considered "annual losses" and are applied every year;
disposal is considered an "end of life loss" and is applied only once for each vintage of
vehicles.6
A The U.S. has submitted a proposal to the Montreal Protocol which, if adopted, would phase-out production and
consumption of HFCs.
B The U.S. EPA has reclamation requirements for refrigerants in place under Title VI of the Clean Air Act.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Emissions Inventory
Table 5-8 Annual In-use Vehicle HFC134a Emission Rate from Vintaging Model
Kind of Loss
Leakage
Maintenance /Servicing
End of Life
Loss Fraction
8%
10%
43%
Of note, the Vintaging Model assumes that charge loss is replaced every year; i.e.,
assuming an 18 percent rate of charge loss, a vehicle with a charge of 1,000 grams would lose a
constant rate of 180 grams per year. While this loss rate is not accurate for any single vehicle, it
is assumed accurate for the fleet as a whole. While other emissions, such as fugitive emissions at
a production facility, leaks from cylinders in storage, etc., are not explicitly modeled, such
emissions are accounted for within the average annual loss rate.
EPA's analysis of the MN database of MY 2010 vehicles suggests that many of the
modeled vehicles likely contain some of the technology required to meet the leakage standard,
and as a consequence are leaking less. We assume that these improvements are independent of
EPA regulation, rather than a preemptive response to regulation. Consequently, this rulemaking
does not take credit for these emission reductions. EPA welcomes better information on HFC
leakage rates in modern vehicles, with a particular emphasis on in-use vehicles.
Based on the MN 2010 database, we determined that it is possible to reduce the FIFC
emissions from these vehicles on average by 13 percent. EPA calculated this based on the
assumption that vehicles currently in the fleet which meet the proposed 2014MY standard would
not make any additional improvements to reduce leakage. We also assumed that the systems
which currently have leakage rates above the proposed standard will reduce their leakage to the
proposed standard level. We then applied the 13 percent reduction to the baseline 18 percent
leakage rate to develop a 15.6 percent leakage rate for 2014 MY and later vehicles to determine
the reduction in emission rate which should be credited to this proposal.
20
We calculated our emission reductions based on the difference between the baseline case
of 2010 vehicle technology (discussed above) and the control scenario where the loss prevention
technology has been applied to 100 percent of the new HD pickup trucks and vans and Class 7/8
tractor starting in 2014 model year, as required by the proposed standards.
Total FIFC reductions are 249 metric tons over the MY 2010 baseline AC system in 2030
and 292 metric tons in 2050. This is equivalent to a reduction of 118,885 metric tons of CC^e in
2018; 355,576 metric tons of CC^eq emissions in 2030; and 417,584 metric tons CC^e in
2050.21
5.4 Greenhouse Gas Emission Impacts
After all the MOVES runs and post-processing was completed, baseline and control case
inventories were totaled for all vehicle types and emission processes to estimate total
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Draft Regulatory Impact Analysis
downstream GHG impacts of the proposal. Table 5-9 summarizes these downstream GHG
impacts and fuel savings from baseline to control case for calendar year 2030. All emissions
impacts reflect the heavy-duty sector only, and do not include emissions from light-duty vehicles
or any other vehicle sector.
Table 5-9 Downstream GHG Impacts in 2030
POLLUTANT
A CO2 (metric tons)
A CH4 (metric tons CO2EQ)
A N2O (metric tons CO2EQ)
A HFC (metric tons CO2EQ)
A Total CO2EQ (metric tons)
A Gasoline Fuel (billion gallons)
A Diesel Fuel (billion gallons)
CALENDAR
YEAR
2030
-58,232,974
279
2,478
-355,576
-58,585,784
-0.373
-5.79
% CHANGE
vs. 2030
BASELINE
-9.32%
0.34%
0.36%
-13%
-9.37%
-6.5%
-9.6%
Table 5-10 summarizes the upstream GHG impacts in 2030. The reductions in GHGs are
proportional to the amount of fuel saved.
Table 5-10 Upstream GHG Impacts in 2030
POLLUTANT
CO2 (metric tons)
CH4 (metric tons CO2EQ)
N2O (metric tons CO2EQ)
Total CO2EQ (metric tons)
CALENDAR
YEAR
2030
-11,794,584
-1,818,733
-56,940
-13,670,257
% CHANGE vs.
2030
BASELINE
-9.3%
-9.3%
-9.3%
-9.3%
5.5 Non-Greenhouse Gas Emission Impacts
After all the MOVES runs and post-processing was completed, baseline and control case
inventories were aggregated for all vehicle types and emission processes to estimate total
downstream non-GHG impacts of the proposal. Table 5-11 summarizes these downstream non-
GHG impacts for calendar year 2030. The non-GHG impacts of the proposal are driven by the
increased use of APUs and, for certain pollutants, improved aerodynamics and tire rolling
resistance. Use of APUs increases PM2.5 downstream inventories compared to the baseline case
because APUs are not required to be equipped with diesel particulate filters, like the on-road
engines are for model year 2007 and later. To a much smaller extent, VMT rebound increases
emissions of all pollutants proportional to the VMT rebound amount.
5-12
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Emissions Inventory
Table 5-11 Downstream impacts for key non-GHG pollutants (Short tons)
POLLUTANT
A 1,3 -Butadiene
A Acetaldehyde
A Acrolein
A Benzene
A Carbon Monoxide
A Formaldehyde
A Oxides of Nitrogen
A Particulate Matter
(below 2.5 micrometers)
A Oxides of Sulfur
A Volatile Organic Compounds
CALENDAR
YEAR
2030
0.5
-1,899
-261
-339
-53709
-6,227
-231631
1,694
-480
-25,121
% CHANGE
vs. 2030
BASELINE
0.1%
-38.0%
-37.9%
-13.5%
-2.0%
-44.5%
-20.6%
7.4%
-9.5%
-17.7%
Non-GHG fuel production and distribution emission impacts of the program were
estimated in conjunction with the development of life cycle GHG emission impacts, and the
GHG emission inventories discussed above. The basic calculation is a function of fuel volumes
in the analysis year and the emission factors associated with each process or subprocess. In
general this life cycle analysis uses the same methodology as the Renewable Fuel Standard
(RFS2) rule. It relies partially on the GREET model, developed by the Department of Energy's
Argonne National Laboratory (ANL), but takes advantage of additional information and models
to significantly strengthen and expand on the GREET analysis.
Updates and enhancements to the GREET model assumptions include updated crude oil
and gasoline transport emission factors that account for recent EPA emission standards and
modeling, such as the Tier 4 diesel truck standards published in 2001 and the locomotive and
commercial marine standards finalized in 200822. In addition, GREET does not include air
toxics. Thus emission factors for the following air toxics were added: benzene, 1,3-butadiene,
formaldehyde, acetaldehyde, and acrolein. These upstream toxics emission factors were
calculated from the 2002 National Emissions Inventory (NEI), a risk and technology review for
petroleum refineries, speciated emission profiles in EPA's SPECIATE database, or the Mobile
Source Air Toxics rule (MSAT) inventory for benzene; these pollutant tons were divided by
refinery energy use or gasoline distribution quantities published by the DOE Energy Information
Administration (EIA) to get emission factors in terms of grams per million BTU of finished
gasoline and diesel.
Results of these emission inventory impact calculations relative to the baseline for 2030
are shown in Table 5-12 for the criteria pollutants and individual air toxic pollutants.
The program is projected to provide reductions in all pollutants associated with gasoline
production and distribution as the projected fuel savings reduce the quantity of gasoline needed.
5-13
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Draft Regulatory Impact Analysis
Table 5-12 Upstream Impacts for Key non-GHG Pollutants (Short Tons)
POLLUTANT
A 1,3 -Butadiene
A Acetaldehyde
A Acrolein
A Benzene
A Carbon Monoxide
A Formaldehyde
A Oxides of Nitrogen
A Particulate Matter
(below 2.5 micrometers)
A Oxides of Sulfur
A Volatile Organic Compounds
CALENDAR YEAR
2030
-1
-4
-1
-19
-3214
-25
-9623
-1331
-6170
-4419
% CHANGE
vs. 2030
BASELINE
-12.5%
-11.1%
-20%
-8.6%
-9.3%
-9.3%
-9.3%
-9.3%
-9.3%
-7.7%
5-14
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Emissions Inventory
References
Intergovernmental Panel on Climate Change Working Group I. 2007. Climate Change 2007 - The Physical
Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on
Climate Change.
2 U.S. Environmental Protection Agency. 2009. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2007.
EPA 430-R-09-004. Available at
http://epa.gov/climatechange/emissions/downloads09/GHG2007entire report-508.pdf
3 U.S. EPA. 2009 Technical Support Document for Endangerment and Cause or Contribute
Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act. Washington, DC. pp. 180-194.
Available at
http://epa.gov/climatechange/endangerment/downloads/Endangerment%20TSD.pdf
4 Argonne National Laboratory. The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation
(GREET) Model versions 1.7 and 1.8. http://www.transportation.anl.gov/modeling simulation/GREET/. Docket
ID: EPA-HQ-OAR-2009-0472-0215
5 Intergovernmental Panel on Climate Change. Chapter 2. Changes in Atmospheric Constituents and in Radiative
Forcing. September 2007. http://www.ipcc.ch/pdf/assessment-report/ar4/wgl/ar4-wgl-chapter2.pdf. Docket ID:
EPA-HQ-OAR-2009-0472-0117
6 http://www.epa.gov/otaq/models/moves/index. htm
7 Memorandum to the Docket "Moves Inputs" Docket Number EPA-HQ-OAR-2010-0162 Docket Identification
Number EPA-HQ-OAR-2010-0162-0153
8 U.S. EPA. Draft Regulatory Impact Analysis: Changes to Renewable Fuel Standard Program. Chapters 2 and
S.May 26, 2009. Docket ID: EPA-HQ-OAR-2009-0472-0119
9 U.S. EPA. 2008. RFS2 Modified version of GREET1.7 Upstream Emissions Spreadsheet, October 31, 2008.
Docket ID: EPA-HQ-OAR-2009-0472-0191
10 Annual Energy Outlook 2010. http://www.eia.doe.gov/oiaf/aeo/
1: http ://www. epa. gov/otaq/fuels/renewablefuels/index. htm
12 Final Rulemaking to Establish Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average
Fuel Economy Standards, Joint Technical Support Document. EPA-420-R-10-901, April 2010.
http://www.epa.gov/otaq/climate/regulations/420rl0901 .pdf
13 Tier 4, less than 8 kW nonroad compression-ignition engine exhaust emissions standards assumed for APUs:
http://www.epa.gov/otaq/standards/nonroad/nonroadci.htm
14 Heavy-duty highway compression ignition engine exhaust emission standards. For MY 2004, HD standard is 2.5
g/bhp-hr NOX+NMHC, with a limit of 0.5 g/bhp-hr NMHC. http://www.epa.gov/otaq/standards/heavv-dutv/hdci-
exhausthtm For MY 2004, HD standard is 2.5 g/bhp-hr NOX+NMHC, with a limit of 0.5 g/bhp-hr NMHC.
15 Hsu ,Y., and Mullen, M. 2007. Compilation of Diesel Emissions Speciation Data. Prepared by E. H. Pechan and
Associates for the Coordinating Research Council. CRC Contract No. E-75, October, 2007. Available at
www.crcao.org.
5-15
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Draft Regulatory Impact Analysis
16Khalek, I., Rougher, T., and Merritt, P. M. 2009. Phase 1 of the Advanced Collaborative Emissions Study.
Prepared by Southwest Research Institute for the Coordinating Research Council and the Health Effects Institute,
June 2009. Available at www.crcao.org.
17 Craig Harvey, EPA, "Calculation of Upstream Emissions for the GHG Vehicle Rule." 2009. Docket ID: EPA-
HQ-OAR-2009-0472-0216
18 This is in agreement with the IPCC report IPCC/TEAP 2005 Safeguarding the Ozone Layer and the Global
Climate System - Issues Related to Hydrofluorocarbons and Perfluorocarbons, which indicates lifetimes
(worldwide) of 9 to 12 years.
19 The Minnesota refrigerant leakage data can be found at
http://www.pca. state.mn.us/climatechange/mobileair.html#leakdata
20 Using 18% as the base emission rate may overstate the net emission reductions. However, (a) the net impact is
very small, (b) these numbers have significant uncertainty, (c) it is unclear what the appropriate modification would
be.
21 Using a Global Warming Potential of 1,430 for HFC-134a.
22 http://www.epa. gov/otaq/marine.htm, http://www.epa.gov/otaq/locomotives.htm
5-16
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Results of Proposed and
Alternative Standards
Chapter 6: Results of Proposed and Alternative Standards
The heavy-duty truck segment is very complex. The sector consists of a diverse group of
impacted parties, including engine manufacturers, chassis manufacturers, truck manufacturers,
trailer manufacturers, truck fleet owners and the air breathing public. The proposal the agencies
have laid out today is largely shaped to maximize the environmental and fuel savings benefits of
the program respecting the unique and varied nature of the regulated industries. In developing
this proposal, we considered a number of alternatives that could have resulted in fewer or
potentially greater GHG and fuel consumption reductions than the program we are proposing.
This section summarizes the alternatives we considered and presents assessments of technology
costs, CC>2 reductions, and fuel savings associated with each alternative. The agencies request
comments on all of these alternatives, including whether a specific alternative could achieve
greater net benefits than the preferred alternative, either for all regulatory categories, or for any
individual regulatory category. The agencies also request comments on whether any specific
additional analyses could provide information that could further inform the selection among
alternatives for the final rule.
6.1 What Are the Alternatives that the Agencies Considered?
In developing alternatives, NHTSA must consider EISA's requirement for the MD/HD
fuel efficiency program noted above. 49 U.S.C. 32902(k)(2) and (3) contain the following three
requirements specific to the MD/HD vehicle fuel efficiency improvement program: (1) The
program must be "designed to achieve the maximum feasible improvement"; (2) the various
required aspects of the program must be appropriate, cost-effective, and technologically feasible
for MD/HD vehicles; and (3) the standards adopted under the program must provide not less than
four model years of lead time and three model years of regulatory stability. In considering these
various requirements, NHTSA will also account for relevant environmental and safety
considerations.
Each of the alternatives proposed by NHTSA and EPA represents, in part, a different way
the agencies could establish a HD program pursuant to EISA and the CAA. The agencies are
proposing Alternative 6. The alternatives below represent a broad range of approaches under
consideration for setting proposed HD vehicle fuel efficiency and GHG emissions standards.
The alternatives that the agencies are proposing, in order of increasing fuel efficiency and GHG
emissions reductions, are:
6.1.1 Alternative 1: No Action
A "no action" alternative assumes that the agencies would not issue a rule regarding a
MD/HD fuel efficiency improvement program, and is considered to comply with National
Environmental Policy Act (NEPA) and to provide an analytical baseline against which to
compare environmental impacts of the other regulatory alternatives.l The agencies refer to this
as the "No Action Alternative" or as a "no increase" or "baseline" alternative.
6-1
-------
Draft Regulatory Impact Analysis
Table 6-1 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 1 (Baseline) [gallons/100
miles]
HD Pickups and
Vans - gasoline
HD Pickups and
Vans- diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.6
6.9
11.3
10.2
20.2
MY 2015
6.6
6.9
11.3
10.2
20.2
MY 2016
6.6
6.9
11.3
10.2
20.2
MY 2017
6.6
6.9
11.3
10.2
20.2
MY 2018
6.6
6.9
11.3
10.2
20.2
As described in Chapter 5, this no-action alternative is considered the reference case.
6.1.2 Alternative 2: Engine Only
The EPA currently regulates heavy-duty engines, i.e., engine manufacturers, rather than
the vehicle as a whole, in order to control criteria emissions.2 Under Alternative 2, the agencies
would similarly set engine performance standards for each vehicle class, Class 2b through Class
8, and would specify an engine cell test procedure, as EPA currently does for criteria pollutants.
HD engine manufacturers would be responsible for ensuring that each engine could meet the
applicable vehicle class engine performance standard when tested in accordance with the
specified engine cell test procedure. Engine manufacturers could improve HD engines by
applying the combinations of fuel efficiency improvements and GHG emissions reduction
technologies to the engine that they deem best achieve that result.
For this scenario, we assumed the following CO2 reductions stated in Table 6-2.
Table 6-2 Estimated Possible Reductions in Engine CO2 Emission Rates in Alternative 2
GVWR CLASS
HHD (8a-8b)
MHD (6-7) and LHD 4-5
LHD 2b-3
FUEL
Diesel
Diesel
Gasoline
Gasoline
Diesel
MODEL YEARS
2014-2016
2017+
2014-2016
2017+
2016+
2016+
2016+
CO2 REDUCTION FROM
REFERENCE CASE
3%
6%
5%
9%
5%
5%
9%
6-2
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Results of Proposed and
Alternative Standards
Table 6-3 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 2 [gallons/100 miles]
HD Pickups
and Vans -
gasoline
HD Pickups
and Vans-
diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.6
6.9
11.3
9.9
19.6
MY 2015
6.6
6.9
11.3
9.9
19.6
MY 2016
6.3
6.3
10.8
9.9
19.6
MY 2017
6.3
6.3
10.8
9.7
19.0
MY 2018
6.3
6.3
10.8
9.7
19.0
6.1.3 Alternative 3: Class 8 Combination Tractors
Combination tractors consume the largest fraction of fuel within the medium- and heavy-
duty truck segment. Tractors also offer significant potential for fuel savings due to the high
annual mileage and high vehicle speed of typical trucks within this segment, as compared to
annual mileage and average speeds/duty cycles of other vehicle classes. This alternative would
set performance standards for both the engine of Class 8 vehicles and the overall vehicle
efficiency performance for the Class 8 combination tractor segment. Under Alternative 3, the
agencies would set an engine performance standard, as discussed under Alternative 2, for Class 8
tractors. In addition, Class 8 combination tractor manufacturers would be required to meet an
overall vehicle performance standard by making various non-engine fuel saving technology
improvements. These non-engine fuel efficiency and GHG emissions improvements could be
accomplished, for example, by a combination of improvements to aerodynamics, lowering tire
rolling resistance, decreasing vehicle mass (weight), reducing fuel use at idle, or by adding
intelligent vehicle technologies.3 Compliance with the overall vehicle standard could be
determined using a computer model that would simulate overall vehicle fuel efficiency given a
set of vehicle component inputs. Using this compliance approach, the Class 8 vehicle
manufacturer would supply certain vehicle characteristics (relating to the categories of
technologies noted immediately above) that would serve as model inputs. The agencies would
supply a standard Class 8 vehicle engine's contribution to overall vehicle efficiency, making the
engine component a constant for purposes of compliance with the overall vehicle performance
standard, such that compliance with the overall vehicle standard could only be achieved via
efficiency improvements to non-engine vehicle components. Thus, vehicle manufacturers could
use any combination of improvements of the non-engine technologies that they believe would
best achieve the Class 8 overall vehicle performance standard. This alternative in NHTSA's
scoping notice involves regulating Class 8 combination tractors only. For this scenario, we
assumed the following CC>2 reductions stated in Table 6-4 and road load improvements stated in
Table 6-5.
6-3
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Draft Regulatory Impact Analysis
Table 6-4 Estimated Possible Reductions in Class 8 Engine CO2 Emission Rates in Alternative 3
GVWR CLASS
HHD (8a-8b)
FUEL
Diesel
MODEL YEARS
2014-2016
2017+
CO2 REDUCTION
FROM REFERENCE
CASE
3%
6%
Table 6-5 Estimated Reductions in Rolling Resistance and Aerodynamic Drag Coefficients for Model Years
2014 and Later in Alternative 3
TRUCK TYPE
Combination long-haul
Combination short-haul
REDUCTION IN TIRE
ROLLING RESISTANCE
COEFFICIENT FROM 2010
MY
8.4%
7.0%
REDUCTION IN
AERODYNAMIC DRAG
COEFFICIENT FROM
2010 MY
7.2%
5.3%
To run MOVES for this alternative, the "samplevehiclepopulation" table was altered such
that only the Class 8 tractors would be output in the combination long-haul and combination
short-haul source types. These source types normally include Class 7 trucks also. Since
MOVES outputs results by source/vehicle type and not engine class, two runs were performed
for combination tractors. The first run included the database with the above changes and with
the Class 7 population set to zero. The second run did not include the above changes but with
the Class 8 population set to zero. The results from these two runs gave Class 8 combination
tractors affected by this alternative and Class 7 combination tractors not affected by this
alternative. The two runs were combined, preserving the total Class 7/8 combination tractor
population, while applying the changes only to the Class 8 combination tractors.
For the purpose of this analysis, it was assumed that 100 percent of Class 8 combination
long-haul tractors model year 2014 and later use APUs during extended idling. This assumption
is based on the expectation that manufacturers will use APUs to meet the vehicle GHG standard
for Class 8 combination long-haul tractors.
6-4
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Results of Proposed and
Alternative Standards
Table 6-6 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 3 [gallons/100 miles]
HD Pickups
and Vans -
gasoline
HD Pickups
and Vans-
diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.6
6.9
11.3
10.2
18.7
MY 2015
6.6
6.9
11.3
10.2
18.7
MY 2016
6.6
6.9
11.3
10.2
18.7
MY 2017
6.6
6.9
11.3
10.2
18.2
MY 2018
6.6
6.9
11.3
10.2
18.2
6.1.4 Alternative 4: Engines and Class 7 and 8 Tractors
This alternative combines Alternative 2 with Alternative 3, and additionally would set an
overall vehicle efficiency performance standard for Class 7 tractors. This alternative would,
thus, set standards for all HD engines and would set overall vehicle performance standards for
Class 7 and 8 tractors, as described for Class 8 combination tractors under Alternative 3. Class 7
tractors make up a small percent of the tractor market, approximately 9 percent.4 Though the
segment is currently small, the agencies believe the inclusion of this class of vehicles would help
prevent a potential class shifting, as noted in the NAS panel report.5
The engine CC>2 reductions are described in Table 6-2, and the road load reductions are
described in Table 6-7. A separate MOVES run was not performed for this scenario since it can
be taken from Alternative 2 and Alternative 6 (described below). The pre-2014 model year
inventories were taken from the baseline run results. The MY2014+ Class 7/8 combination
tractor inventories were taken from the Alternative 6 run results, and the MY2014+ numbers for
the remainder of the heavy-duty vehicles were taken from the Alternative 2 results. It was
assumed that 100 percent of Class 7/8 combination long-haul tractors model year 2014 and later
use APUs during extended idling. This assumption is based on the expectation that
manufacturers will use APUs to meet the vehicle GHG standard for combination long-haul
tractors.
6-5
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Draft Regulatory Impact Analysis
Table 6-7 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 4 [gallons/100 miles]
HD Pickups
and Vans -
gasoline
HD Pickups
and Vans-
diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.6
6.9
11.3
9.9
18.5
MY 2015
6.6
6.9
11.3
9.9
18.5
MY 2016
6.3
6.3
10.8
9.9
18.5
MY 2017
6.3
6.3
10.8
9.7
17.9
MY 2018
6.3
6.3
10.8
9.7
17.9
6.1.5 Alternative 5: Engines, Class 7 and 8 Tractors, and HD Pickup Trucks
and Vans
This alternative builds on Alternative 4 through the addition of an overall vehicle
efficiency performance standard for HD Pickup Trucks and Vans (or work trucks). Therefore,
under this alternative, the agencies would set engine performance standards for each HD vehicle
class, and would also set overall vehicle performance standards for Class 7 and 8 tractors, as well
as for HD Pickup Trucks and Vans. Compliance for the HD pickup trucks and vans would be
determined through a fleet averaging process similar to determining passenger car and light truck
compliance with CAFE standards.
This is a combination of Alternative 4 with the addition of HD pickup trucks and vans.
As with Alterative 4, a separate MOVES run was not performed. The pre-2014 model year
inventories were taken from the baseline run results. The MY2014+ Class 7/8 combination
tractor and HD pickup truck and van inventories were taken from the Alternative 6 run results,
and the MY2014+ numbers for the remainder of the heavy-duty vehicles were taken from the
Alternative 2 results. It was assumed that 100 percent of Class 7/8 combination long-haul
tractors model year 2014 and later use APUs during extended idling.
6-6
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Results of Proposed and
Alternative Standards
Table 6-8 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 5 [gallons/100 miles]
HD Pickups
and Vans -
gasoline
HD Pickups
and Vans-
diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.5
6.8
11.3
9.9
18.5
MY 2015
6.5
6.7
11.3
9.9
18.5
MY 2016
6.4
6.5
10.8
9.9
18.5
MY 2017
6.2
6.3
10.8
9.7
17.9
MY 2018
6.0
5.9
10.8
9.7
17.9
6.1.6 Alternative 6: Engines, Tractors, and Class 2b through 8 Trucks.
Alternative 6 represents the agencies' preferred approach. This alternative would set
engine efficiency standards, engine GHG emissions standards, overall vehicle fuel efficiency
standards, and overall vehicle GHG emissions standards for HD pickup trucks and vans and the
remaining Class 2b through Class 8 trucks and the engines installed in them. This alternative
essentially sets fuel efficiency and GHG emissions performance standards for both the engines
and the overall vehicles in the entire heavy-duty truck sector. Compliance with each vehicle
class's engine performance standard would be determined as discussed in the description of
Alternative 2. Compliance with the tractor and vocational vehicle classes' overall vehicle
performance standard (Class 3 through 8 trucks) would be determined as discussed in the
description of Alternative 3. Compliance for the Class 2b and 3 pickup trucks and vans would be
determined as described in Alternative 5.
This is the proposed rule. Details regarding this alternative are included in Chapter 5.
Table 6-9 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 6 [gallons/100 miles]
HD Pickups
and Vans -
gasoline
HD Pickups
and Vans-
diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.5
6.8
11.3
9.7
18.5
MY 2015
6.5
6.7
11.3
9.7
18.5
MY 2016
6.4
6.5
10.7
9.7
18.5
MY 2017
6.2
6.3
10.7
9.3
17.9
MY 2018
6.0
5.9
10.7
9.3
17.9
6-7
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Draft Regulatory Impact Analysis
The agencies also evaluated two scenarios related to Alternative 6 but with stringency
levels which are 15 percent less stringent and 20 percent more stringent. These alternatives are
referred to as Alternatives 6a and 6b.
6.1.6.1 Alternative 6a: Engines, Tractors, and Class 2b through 8 Trucks
Alternative 6a represents an alternative stringency level to the agencies' preferred
approach. Like Alternative 6, this alternative would set GHG emissions and fuel efficiency
standards for HD pickup trucks and vans and for Class 2b through 8 vocational vehicles and
combination tractors and the engines installed in them. The difference between Alternative 6 and
6a is the level of stringency for each of the proposed standards. Alternative 6a represents a
stringency level which is approximately 15 percent less stringent than the preferred approach.
The agencies calculated the stringency level in order to meet two goals. First, we desired to
create an alternative that was closely related to the proposal (within 10-20 percent of the
preferred alternative). Second we wanted an alternative that reflected removal of the last
technology we believed manufacturers would add in order to meet the preferred alternative. In
other words, we wanted an alternative that as closely as possible reflected the last increment in
stringency prior to reaching our preferred alternative. In general, this could be thought of as
removing the least cost effective (final) step. Please see Table 2.35 in RIA Chapter 2 for a list of
all of the technologies, their cost and relative effectiveness. The resulting Alternative 6a is based
on the same technologies used in Alternative 6 except as follows:
• The combination tractor standard would be based removal of the Advanced
SmartWay aerodynamic package and weight reduction technologies which
reduces the average combination tractor savings by approximately 1 percent. The
road load impacts of this alternative are listed in Table 6-10.
• The HD pickup truck and van standard would be based on removal of
aerodynamics which reduces the average truck savings by approximately 2
percent. The estimated total vehicle CO2 reductions for this alternative are listed
in Table 6-11.
• The vocational vehicle standard would be based on removal of low rolling
resistant tires which reduces the average vehicle savings by approximately 2
percent.
6-8
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Results of Proposed and
Alternative Standards
Table 6-10 Estimated Reductions in Rolling Resistance and Aerodynamic Drag Coefficients from Reference
Case for Alternative 6a (Model Years 2014 and Later)
TRUCK TYPE
Combination long-haul
Combination short-haul
REDUCTION IN TIRE
ROLLING RESISTANCE
COEFFICIENT FROM 2010
MY
8.4%
7.0%
REDUCTION IN
AERODYNAMIC DRAG
COEFFICIENT FROM
2010 MY
6.1%
4.6%
Table 6-11 Estimated Total Vehicle CO2 Reductions for HD Pickup Trucks and Vans
GVWR
CLASS
LHD 2b-3
FUEL
Gasoline
Diesel
MODEL
YEARS
2014
2015
2016
2017
2018+
2014
2015
2016
2017
2018+
CO2 REDUCTION
FROM BASELINE
1.2%
1.6%
3.2%
4.8%
8.0%
1.99%
2.6%
5.2%
7.8%
13.0%
The estimated fleet-wide fuel efficiency for Alternative 6a is listed in Table 6-12.
Table 6-12 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 6a [gallons/100 miles]
HD Pickups
and Vans -
gasoline
HD Pickups
and Vans-
diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.6
6.8
11.3
9.9
18.5
MY 2015
6.5
6.7
11.3
9.9
18.5
MY 2016
6.4
6.6
10.8
9.9
18.5
MY 2017
6.3
6.4
10.8
9.7
17.9
MY 2018
6.1
6.0
10.8
9.7
17.9
6-9
-------
Draft Regulatory Impact Analysis
6.1.6.2 Alternative 6b: Engines, Tractors, and Class 2b through 8 Trucks
Alternative 6b represents an alternative stringency level to the agencies' preferred
approach. Like Alternative 6, this alternative would set GHG emissions and fuel efficiency
standards for HD pickup trucks and vans and for Class 2b through 8 vocational vehicles and
combination tractors and the engines installed in them. The difference between Alternative 6 and
6b is the level of stringency for each of the proposed standards. Alternative 6b represents a
stringency level which is 20 percent more stringent than the preferred approach. The agencies
calculated the stringency level based on similar goals as for Alternative 6a. Specifically, we
wanted an alternative that would reflect an incremental improvement over the preferred
alternative based on the technologies we thought most likely to be applied by manufacturers if a
more stringent standard were set. In general, this could be thought of as adding the next most
cost effective technology in each of the categories. However, as discussed in the feasibility
discussion in Section III, we are not proposing this level of stringency because we do not believe
that these technologies can be developed and introduced in the timeframe of this rulemaking.
Reflecting that given unlimited resources it might be possible to introduce these technologies in
this timeframe, but our inability to estimate what those real costs might be (e.g. to build new
factories in only one to two years), we have denoted the cost for this alternative with a +c. The
+c is intended to make clear that the cost estimates we are showing do not include additional
costs related to pulling ahead the development and expanding manufacturing base for these
technologies.. The resulting Alternative 6b is based on the same technologies used in
Alternative 6 except as follows:
• The combination tractor standard would be based on the addition of rankine waste
heat recovery to the HD engines installed in combination tractors with sleeper
cabs. The agencies assumed a 12 kWh waste heat recovery system would reduce
CO2 emissions by 6 percent at a cost of $8,400 per truck.6 The agencies applied
waste heat recovery systems to 80 percent of sleeper cabs. The estimated
reduction for this alternative is included in Table 6-13.
• HD pickup truck and van standard would be based on the addition of a 10 percent
mass reduction which would increase the average truck savings by approximately
2 percent over Alternative 6. The estimated total vehicle CO2 reductions for this
alternative are listed in Table 6-14.
• Vocational vehicle standard would be based on the addition hybrid powertrains to
8 percent of the vehicles. The agencies assumed a 25 percent per vehicle GHG
emissions and fuel consumption savings due to the hybrid with a cost of $30,000
per vehicle.7 The agencies project the hybrid penetration for this alternative, as
described in Table 6-15.
6-10
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Results of Proposed and
Alternative Standards
Table 6-13 Estimated Reductions in Engine CO2 Emission Rates from this Alternative 6b
GVWR CLASS
HHD (8a-8b) -
Combination tractors only
FUEL
Diesel
MODEL YEARS
2014-2016
2017+
CO2 REDUCTION
FROM REFERENCE
CASE
5%
8%
Table 6-14 Estimated Total Vehicle CO2 Reductions for HD Pickup Trucks and Vans for Alternative 6b
GVWR
CLASS
LHD 2b-3
FUEL
Gasoline
Diesel
MODEL
YEARS
2014
2015
2016
2017
2018+
2014
2015
2016
2017
2018+
CO2 REDUCTION
FROM BASELINE
1.8%
2.4%
4.8%
7.2%
12.0%
2.61%
3.4%
6.8%
10.2%
17.0%
Table 6-15 Hybrid Penetration for Vocational Vehicles for Alternative 6b
Vocational Vehicles
MY 2014
0%
MY 2017
8%
The estimated fleet-wide fuel efficiency for Alternative 6b is listed in Table 6-16.
6-11
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Draft Regulatory Impact Analysis
Table 6-16 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 6b [gallons/100 miles]
HD Pickups
and Vans -
gasoline
HD Pickups
and Vans-
diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.5
6.7
11.3
9.7
18.1
MY 2015
6.5
6.7
11.3
9.7
18.1
MY 2016
6.3
6.4
10.7
9.7
18.1
MY 2017
6.2
6.2
10.7
9.1
17.6
MY 2018
5.8
5.7
10.7
9.1
17.6
6.1.7 Alternative 7: Engines, Tractors, Trucks, and Trailers.
This alternative builds on Alternative 6 by adding a performance standard for fuel
efficiency and GHG emissions of commercial trailers. Therefore, this alternative would include
fuel efficiency performance standards and GHG emissions standards for Class 2b and 3 work
truck and Class 3 through Class 8 vocational vehicle engines, and the performance standards for
the overall fuel efficiency and GHG emissions of those vehicles, as described above.
This is Alternative 6 with the addition of a regulation of trailers on combination tractors.
All assumptions are the same as Alternative 6 except for road load. This alternative would result
in further reductions in drag coefficient and rolling resistance coefficient from the MY 2010
baseline. Table 6-17 describes the road load reductions.
Table 6-17 Estimated Reductions in Rolling Resistance and Aerodynamic Drag Coefficients from Reference
Case for Alternative 7 (Model Years 2014 and Later)
TRUCK TYPE
Combination long-haul
Combination short-haul
Straight trucks, refuse trucks,
motor homes, transit buses,
and other vocational vehicles
REDUCTION IN TIRE
ROLLING RESISTANCE
COEFFICIENT FROM 2010
MY
10.7%
10.0%
10.0%
REDUCTION IN
AERODYNAMIC DRAG
COEFFICIENT FROM
2010 MY
9.2%
10.6%
0%
Since the only difference between Alternatives 6 and 7 was the inclusion of trailers, a
MOVES run involving only combination tractors with the above changes was performed. For all
other heavy-duty vehicles, the results from Alternative 6 were used for Alternative 7. The fuel
economy results for Alternative 7 are summarized in Table 6-18.
6-12
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Results of Proposed and
Alternative Standards
The costs for the trailer program of Alternative 7 were derived based on the assumption
that trailer aerodynamic improvements would cost $2,150 per trailer. This cost assumes side
fairings and gap reducers and is based on the ICF cost estimate. The agencies applied the
aerodynamic improvement to only box trailers, which represent approximately 60 percent of the
trailer sales. The agencies used $624 per trailer for low rolling resistance based on the agencies'
estimate of $78 per tire in the tractor program. Lastly, the agencies assumed the trailer volume is
equal to three times the tractor volume based on the 3:1 ratio of trailers to tractors in the market
today.
Table 6-18 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 7 [gallons/100 miles]
HD Pickups
and Vans -
gasoline
HD Pickups
and Vans-
diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.5
6.8
11.3
9.7
18.2
MY 2015
6.5
6.7
11.3
9.7
18.2
MY 2016
6.4
6.5
10.7
9.7
18.2
MY 2017
6.2
6.3
10.7
9.3
17.7
MY 2018
6.0
5.9
10.7
9.3
17.7
6.1.8 Alternative 8: Engines, Tractors, Trucks, and Trailers with Hybrid
Powertrains
Alternative 8 includes all elements of Alternative 7, plus the application of hybrid
powertrains to the pickup trucks, vans, vocational vehicles, and tractors by the 2014 and the
2017 MY. The agencies set the hybrid penetration for each class, as described in Table 6-19.
The agencies do not believe that it is possible to achieve hybrid technology penetration rates at or
even near these levels in the timeframe of this rulemaking. However, we believe it is useful to
consider what a future standard based on the use of such advanced technologies could achieve.
As with Alternative 6b, we include a +c in our cost estimates for this alternative to reflect
additional costs not estimated by the agencies. The agencies assumed a 25 percent reduction to
o
CC>2 emissions and fuel consumption, based on the findings of the NAS report. The agencies
also project a cost of $30,000 per vehicle for the vocational vehicles and combination tractors,
which is the median value described in the NAS report for the vocational vehicles and tractors.
The agencies are projecting a cost of $9,000 per vehicle for the HD pickup trucks and vans,
again based on the NAS report.9
6-13
-------
Draft Regulatory Impact Analysis
Table 6-19: Hybrid Penetration by Vehicle Class
HD Pickup Trucks & Vans
Vocational Vehicles
Combination tractors
MY 2014
10,000 units
10,000 units
0%
MY 2017
50%
50%
0%
Since the only difference between Alternatives 7 and 8 was the penetration of hybrid
technology in the vocational vehicle and HD pickup and van categories, a MOVES run involving
only vocational vehicles and HD pickups and vans was performed. In vocational vehicles, EPA
assumed that hybrid technology would be applied only in diesel-fueled trucks. In HD pickups
and vans, EPA assumed that hybrid technology would be evenly divided between diesel and
gasoline vehicles. The fuel economy results for Alternative 8 are summarized in Table 6-20.
Table 6-20 Estimated Fleet-Wide Fuel Efficiency by Model Year for Alternative 8 [gallons/100 miles]
HD Pickups
and Vans -
gasoline
HD Pickups
and Vans-
diesel
Vocational -
gasoline
Vocational -
diesel
Comb, tractors
MY 20 10-20 13
6.7
6.9
11.4
10.2
20.2
MY 2014
6.5
6.8
11.3
9.6
18.2
MY 2015
6.5
6.7
11.3
9.6
18.2
MY 2016
6.4
6.5
10.7
9.6
18.2
MY 2017
5.5
5.5
10.7
8.0
17.7
MY 2018
5.2
5.1
10.7
8.0
17.7
6.2 How Do These Alternatives Compare in Overall GHG Emissions
Reductions and Fuel Efficiency and Cost?
The agencies analyzed all ten alternatives through MOVES to evaluate the impact of each
proposed alternative, as shown in Table 6-21. The table contains the annual CO2 and fuel
savings in 2030 and 2050 for each alternative (relative to the reference scenario of Alternative 1),
presenting both the total savings across all regulatory categories, and for each regulatory
category. Table 6-22 presents the annual technology costs associated with each alternative
(relative to the reference scenario of Alternative 1) in 2030 and 2050 for each regulatory
category. Finally, the total annual downstream impacts of NOX, CO, PM, and VOC emissions in
2030 for each of the alternatives are included in Table 6-23. The agencies request comment on
whether any of these alternatives could achieve greater new benefits than the preferred
alternative, either for all regulatory categories, or for any individual regulatory category.
6-14
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Results of Proposed and
Alternative Standards
Table 6-21: Annual CO2 and Oil Savings in 2030 and 2050
Alt. 1
Alt. 2 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 3 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 4 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 5 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 6a - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Preferred - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 6b - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 7 - Total
Tractors
DOWNSTREAM CO2
SAVINGS (MMT)
2030
0
29
19
4
6
35
35
0
0
50
40
4
6
54
40
8
6
52
39
7
6
58
40
8
10
68
46
9
13
62
40
2050
0
46
27
7
13
50
50
0
0
76
57
7
13
82
57
13
13
79
56
11
13
91
57
13
21
107
65
15
27
96
57
OIL SAVINGS (BILLION
GALLONS)
2030
0
2.9
1.8
0.4
0.6
3.4
3.4
0
0
5.0
3.9
0.4
0.6
5.4
3.9
0.8
0.6
5.1
3.8
0.7
0.6
5.8
3.9
0.8
1.0
6.7
4.5
1.0
1.3
6.1
3.9
2050
0
4.6
2.6
0.7
1.2
4.9
4.9
0
0
7.5
5.6
0.7
1.2
8.2
5.6
1.3
1.2
7.8
5.5
1.1
1.2
9.0
5.6
1.3
2.1
10.6
6.4
1.6
2.6
9.5
5.6
6-15
-------
Draft Regulatory Impact Analysis
HD Pickup Trucks
Vocational Vehicles
Trailers
Alt. 8 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Trailers
8
10
4
86
40
16
26
4
13
21
5
142
57
25
55
5
0.8
1.0
0.4
8.4
3.9
1.6
2.5
0.4
1.3
2.1
0.5
14.2
5.6
2.7
5.4
0.5
Table 6-22: Technology Cost Projections for the Alternatives"
Alt. 1
Alt. 2 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 3 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 4 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 5 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt. 6a - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Preferred - Total
Tractors
TECHNOLOGY COSTS (2008$
MILLIONS)
2030
$0
$532
$119
$235
$178
$708
$708
$0
$0
$1,155
$742
$235
$178
$1,882
$742
$962
$178
$1,592
$487
$927
$178
$1,945
$742
2050
$0
$749
$157
$273
$319
$938
$938
$0
$0
$1,574
$982
$273
$319
$2,420
$982
$1,119
$319
$2,041
$645
$1,078
$319
$2,537
$982
6-16
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Results of Proposed and
Alternative Standards
HD Pickup Trucks
Vocational Vehicles
Alt.
6b - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Alt.
7 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Trailers
Alt.
8 - Total
Tractors
HD Pickup Trucks
Vocational Vehicles
Trailers
$962
$241
$4,984+c
$l,375+c
$l,301+c
$2,307+c
$2,885
$742
$962
$241
$910
$35,477 +c
$742
$7,760 +c
$26,065+c
$910
$1,119
$436
$7,575+c
$l,819+c
$l,514+c
$4,24 1+c
$3,740
$982
$1,119
$436
$1,203
$59,000+c
$982
$8,809+c
$48,006+c
$1,203
' The +c is intended to make clear that the cost estimates we are showing do not include additional costs related to
pulling ahead the development and expanding manufacturing base for these technologies.
Table 6-23 Downstream Impacts Relative to Alternative 1 of Key Non-GHGs for Each Alterative in 2030
Alt. 1
Alt. 2
Alt. 3
Alt. 4
Alt. 5
Alt. 6a
Preferred
Alt. 6b
Alt. 7
Alt. 8
NOX
0%
0.60%
-20.2%
-20.5%
-20.5%
-20.5%
-20.6%
-20.8%
-20.9%
-20.9%
CO
0%
0.32%
-2.3%
-2.0%
-2.0%
-2.0%
-2.0%
-2.0%
-2.0%
-2.0%
PM2.5
0%
0.47%
6.8%
7.4%
7.4%
7.4%
7.4%
7.4%
7.3%
7.3%
voc
0%
-0.26%
-17.1%
-17.5%
-17.6%
-17.5%
-17.7%
-17.9%
-17.8%
-17.8%
6-17
-------
Draft Regulatory Impact Analysis
References
1 NEPA requires agencies to consider a "no action" alternative in their NEPA analyses and to compare the effects of
not taking action with the effects of the reasonable action alternatives to demonstrate the different environmental
effects of the action alternatives. See 40 CFR 1502.2(e), 1502.14(d).CEQ has explained that "[T]he regulations
require the analysis of the no action alternative even if the agency is under a court order or legislative command to
act. This analysis provides a benchmark, enabling decision makers to compare the magnitude of environmental
effects of the action alternatives. It is also an example of a reasonable alternative outside the jurisdiction of the
agency which must be analyzed. [See 40 CFR 1502.14(c).] * * * Inclusion of such an analysis in the EIS is
necessary to inform Congress, the public, and the President as intended by NEPA. [See 40 CFR 1500. l(a).]" Forty
Most Asked Questions Concerning CEQ's National Environmental Policy Act Regulations, 46 FR 18026 (1981)
(emphasis added).
2 There are several reasons for this approach. In many cases the engine and chassis are produced by different
manufacturers and it is more efficient to hold a single entity responsible. Also, testing an engine cell is more
accurate and repeatable than testing a whole vehicle.
3 See the MD/HD NAS Report for discussions of the potential fuel efficiency improvement technologies that can be
applied to each of these vehicle components. MD/HD NAS Report, supra note 9, Chapter 5.
4 MJ Bradley. Heavy Duty Market Analysis. 2009.
5 NAS. Page 152.
6TIAX. 2009. Page 4-20.
7 NAS Report. Page 146.
8 NAS Report. Page 146.
9 NAS Report. Page 146.
6-18
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Cost per Ton
Chapter 7: Truck Costs and Costs per Ton of GHG
7.1 Costs Associated with the Proposed Program
In this section, the agencies present our estimate of the costs associated with the proposed
program. The presentation here summarizes the costs associated with new technology expected
to be added to meet the proposed GHG and fuel consumption standards, including hardware
costs to comply with the air conditioning (A/C) leakage program. The analysis summarized here
provides our estimate of incremental costs on a per truck basis and on an annual total basis.
The presentation here summarizes the best estimate by EPA and NHTSA staff as to the
technology mix expected to be employed for compliance. For details behind the cost estimates
associated with individual technologies, the reader is directed to Section III of the preamble and
to Chapter 2 of the draft RIA.
With respect to the cost estimates presented here, the agencies note that, because these
estimates relate to technologies which are in most cases already available, these cost estimates
are technically robust.
7.1.1 Technology Costs per Truck
For the HD pickup trucks and vans, the agencies have used a methodology consistent
with that used for our recent light-duty joint rulemaking since most of the technologies expected
for HD pickup trucks and vans is consistent with that expected for the larger light-duty trucks.
The cost estimates presented in the recent light-duty joint rulemaking were then scaled upward to
account for the larger weight, towing capacity, and work demands of the trucks in these heavier
classes. For details on that scaling process and the resultant costs for individual technologies, the
reader is directed to Section III of the preamble and to Chapter 2 of the draft RIA. Note also that
all cost estimates have been updated to 2008 dollars for this analysis while the recent light-duty
joint rulemaking was presented in 2007 dollars.l
For the loose heavy-duty gasoline engines, we have used engine-related costs from the
HD pickup truck and van estimates since the loose heavy-duty gasoline engines are essentially
the same engines as those sold into the HD pickup truck and van market.
For heavy-duty diesel engines, the agencies have estimated costs using a different
methodology than that employed in the recent light-duty joint rulemaking. In the recent light-
duty joint rulemaking, the fixed costs were included in the hardware costs via an indirect cost
multiplier. As such, the hardware costs presented in that analysis, and in the cost estimates for
HD pickup trucks and vans and HD gasoline engines, included both the actual hardware and the
associated fixed costs. For this analysis, some of the fixed costs are estimated separately for HD
diesel engines and are presented separately from the technology costs. These fixed costs are
referred to as "Other Engineering Costs" as shown in Table 7-2 and described in the text
surrounding that table. Importantly, once totaled both methodologies account for all the costs
associated with the proposal. As noted above, all costs are presented in 2008 dollars.
7-1
-------
Draft Regulatory Impact Analysis
The estimates of vehicle compliance costs cover the years leading up to - 2012 and 2013
- and including implementation of the program - 2014 through 2018. Also presented are costs
for the years following implementation to shed light on the long term (2022 and later) cost
impacts of the program. The year 2022 was chosen here consistent with the recent light-duty
joint rulemaking. That year was considered long term in that analysis because the short-term and
long-term markup factors described shortly below are applied in five year increments with the
2012 through 2016 implementation span and the 2017 through 2021 span both representing the
short-term. Since many of the costs used in this analysis are based on costs in the recent light-
duty joint rulemaking analysis, consistency with that analysis seems appropriate.
Individual technology cost estimates are presented in Chapter 2 of this draft RIA, and
account for both the direct and indirect costs incurred. As described fully in Chapter 2 of this
draft RIA, the agencies have also considered the impacts of manufacturer learning on the
technology cost estimates.
The technology cost estimates discussed in Section III of the preamble and detailed in
Chapter 2 of the draft RIA are used to build up technology package cost estimates. For each
engine and truck category, a single package for each was developed capable of complying with
the proposed standards and the costs for each package was generated. The technology packages
and package costs are discussed in more detail in Chapter 2 of the draft RIA. The compliance
cost estimates take into account all credits and trading programs and include costs associated
with air conditioning controls.
Table 7-1 presents the average incremental costs per truck for this proposal. For HD
pickups and vans, costs increase as the standards become more stringent in 2014 through 2018.
Following 2018, costs then decrease going forward as learning effects result in decreased costs
for individual technologies. By 2022, the long term ICMs take effect and costs decrease yet
again. For vocational vehicles, cost trends are more difficult to discern as diesel engines begin
adding technology in 2014, gasoline engines begin adding technology in 2016, and the trucks
themselves begin adding technology in 2014. With learning effects the costs, in general,
decrease each year except for the heavy-duty gasoline engine changes in 2016. Long term ICMs
take effect in 2022 to provide more cost reductions. For combination tractors, costs generally
decrease each year due to learning effects with the exception of 2017 when the engines placed in
sleeper cab tractors add turbo compounding. Following that, learning impacts result in cost
reductions and the long term ICMs take effect in 2022 for further cost reductions. By 2030 and
later, cost per truck estimates remain constant for all categories. Regarding the long term ICMs
taking effect in 2022, the agencies consider this the point at which some indirect costs decrease
or are no longer considered attributable to the program (e.g., warranty costs go down). Costs per
truck remain essentially constant thereafter.
7-2
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Cost per Ton
Table 7-1 Estimated Hardware Cost per Truck (2008 dollars)
YEAR
2014
2015
2016
2017
2018
2020
2030
2040
2050
HD PICKUPS
&VANS
$225
$292
$567
$848
$1,411
$1,406
$1,350
$1,350
$1,350
VOCATIONAL
$374
$367
$400
$392
$359
$343
$280
$275
$275
COMBINATION
TRACTORS
$5,896
$5,733
$5,480
$6,150
$5,901
$5,661
$4,686
$4,686
$4,686
As noted above, the fixed costs were estimated separately from the hardware costs for
the HD diesel engines. Those fixed costs are not included in Table 7-1. The agencies have
estimated the R&D costs at $6.75 million per manufacturer per year for five years and the new
test cell costs (to accommodate measurement of N2O emissions) at $100,000 per manufacturer.
These costs apply individually for LHD, MHD and HHD diesel engines. Given the 14
manufacturers impacted by the proposed standards, 11 of which are estimated to sell both MHD
and HHD diesel engines and 3 of which are estimated to sell LHD diesel engines, we have
estimated a five year annual R&D cost of $168.8 million dollars (2 x 11 x $6.75 million plus 3 x
$6.75 million for each year 2012-2016) and a one-time test cell cost of $2.5 million dollars (2 x
11 x $100,000 plus 3 x $100,000 in 2013). Estimating annual sales of HD diesel engines at
roughly 600,000 units results in roughly $280 per engine per year for five years beginning in
2012 and ending in 2016. Again, these costs are not reflected in, but are included in Table 7-2 as
"Other Engineering Costs".
The certification and compliance program costs, for all engine and truck types, are
estimated at $4.4 million per year and are expected to continue indefinitely. These costs are
detailed in the "Draft Supporting Statement for Information Collection Request" which is
contained in the docket for this rule.2 Estimating annual sales of heavy-duty trucks at roughly
1.5 million units would result in $3 per engine/truck per year. These costs are not reflected in
Table VIII-1, but are included in Table VIII-2 as "Compliance Program" costs.
7.1.2 Annual Costs of the Proposal
The costs presented here represent the incremental costs for newly added technology to
comply with the proposal. Together with the projected increases in truck sales, the increases in
per-truck average costs shown in above result in the total annual costs presented in Table 7-2
below. Note that the costs presented in Table 7-2 do not include the savings that would occur as
a result of the improvements to fuel consumption. Those impacts are presented in Chapter 7.2
below.
7-3
-------
Draft Regulatory Impact Analysis
Table 7-2 Annual Costs Associated with the Proposal (SMillions of 2008 dollars)
YEAR
2012
2013
2014
2015
2016
2017
2018
2020
2030
2040
2050
NPV,
to/
NPV,
HO/
HD PICKUPS
&VANS
$0
$0
$177
$213
$404
$601
$1,011
$971
$962
$1,038
$1,119
$18,770
$9,657
VOCATIONAL
$0
$0
$208
$211
$237
$240
$226
$229
$241
$332
$436
$5,728
$2,977
COMBINATION
TRACTORS
$0
$0
$720
$713
$693
$792
$776
$777
$742
$850
$982
$16,707
$9,114
OTHER
ENGINEERING
COSTSA
$169
$171
$169
$169
$169
$0
$0
$0
$0
$0
$0
$787
$718
COMPLIANCE
PROGRAM
COSTS
$0
$4.4
$4.4
$4.4
$4.4
$4.4
$4.4
$4.4
$4.4
$4.4
$4.4
$98
$56
ANNUAL
COSTS
$169
$176
$1,278
$1,310
$1,507
$1,638
$2,019
$1,981
$1,950
$2,224
$2,541
$42,089
$22,522
A "Other Engineering Costs" are described in Section 7.1.1. These costs represent fixed costs for heavy-duty
diesel engines.
7.2 Cost per Ton of GHG Emissions Reduced
The agencies have calculated the cost per ton of GHG (CC^-equivalent, or CO2e)
reductions associated with this rule using the above costs and the GHG emissions reductions
described in Chapter 5. These values are presented in Table 7-3 through Table 7-6 for HD
pickup trucks & vans, Vocational vehicles, Combination tractors and the Proposal (i.e., all
engines and trucks), respectively. The cost per metric ton of GHG emissions reductions has been
calculated in the years 2020, 2030, 2040, and 2050 using the annual vehicle compliance costs
and emission reductions for each of those years. The value in 2050 represents the long-term cost
per ton of the emissions reduced. The agencies have also calculated the cost per metric ton of
GHG emission reductions including the savings associated with reduced fuel consumption
(presented below in Tables 7-3 through 7-6). This latter calculation does not include the other
benefits associated with this proposal such as those associated with criteria pollutant reductions
or energy security benefits (discussed in Chapter 9). By including the fuel savings in the cost
estimates, the cost per ton is less than $0 since the estimated value of fuel savings outweighs the
program costs. Also of interest is the cumulative cost per ton of cumulative CC^e reductions.
These values are shown in Table 7-7 both with and without cumulative fuel savings.
7-4
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Cost per Ton
Table 7-3 Annual Cost per Metric Ton of CO2e Reduced - HD Pickup Trucks & Vans (2008 dollars)
YEAR
2020
2030
2040
2050
PROGRAM
COST
$1,000
$1,000
$1,000
$1,100
FUEL
SAVINGS
(POST-TAX)
$1,000
$3,000
$4,600
$5,800
C02E
REDUCED
4
10
13
16
COST PER
TON
(WITHOUT
FUEL
SAVINGS)
$270
$100
$70
$70
COST PER
TON (WITH
FUEL
SAVINGS)
$0
-$200
-$270
-$290
Table 7-4 Annual Cost per Metric Ton of CO2e Reduced - Vocational Vehicles (2008 dollars)
YEAR
2020
2030
2040
2050
PROGRAM
COST
$200
$200
$300
$400
FUEL
SAVINGS
(POST-TAX)
$1,500
$3,700
$6,400
$8,900
CO2E
REDUCED
6
13
19
26
COST PER
TON
(WITHOUT
FUEL
SAVINGS)
$30
$20
$20
$20
COST PER
TON (WITH
FUEL
SAVINGS)
-$220
-$280
-$320
-$330
Table 7-5 Annual Cost per Metric Ton of CO2e Reduced - Combination Tractors (2008 dollars)
YEAR
2020
2030
2040
2050
PROGRAM
COST
$800
$700
$800
$1,000
FUEL
SAVINGS
(POST-TAX)
$6,700
$14,500
$19,800
$23,700
C02E
REDUCED
26
48
59
67
COST PER
TON
(WITHOUT
FUEL
SAVINGS)
$30
$10
$10
$10
COST PER
TON (WITH
FUEL
SAVINGS)
-$230
-$280
-$320
-$340
Table 7-6 Annual Cost per Metric Ton of CO2e Reduced - Proposal (2008 dollars)
YEAR
2020
2030
2040
2050
PROGRAM
COST
$2,000
$1,900
$2,200
$2,500
FUEL
SAVINGS
(POST-TAX)
$9,300
$21,200
$30,800
$38,400
CO2E
REDUCED
35
71
91
109
COST PER
TON
(WITHOUT
FUEL
SAVINGS)
$50
$30
$20
$20
COST PER
TON (WITH
FUEL
SAVINGS)
-$210
-$270
-$310
-$330
7-5
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Draft Regulatory Impact Analysis
Table 7-7 Cumulative Cost per Cumulative Metric Ton of CO2e Reduced (2008 dollars)
YEAR
2020
2030
2040
2050
PROGRAM
COST
$12,100
$31,300
$52,300
$76,200
FUEL SAVINGS
(POST-TAX)
$32,200
$197,100
$462,100
$811,100
C02E
REDUCED
133
700
1,525
2,536
COST PER TON
(WITHOUT
FUEL SAVINGS)
$90
$40
$30
$30
COST PER
TON (WITH
FUEL
SAVINGS)
-$150
-$240
-$270
-$290
7.3 Impacts of Reduction in Fuel Consumption
7.3.1 Gallons Reduced under the Proposal
The new CC>2 standards will result in significant improvements in the fuel efficiency of
affected trucks. Drivers of those trucks will see corresponding savings associated with reduced
fuel expenditures. The agencies have estimated the impacts on fuel consumption for the tailpipe
CC>2 standards. To do this, fuel consumption is calculated using both current CC>2 emission
levels and the new CC>2 standards. The difference between these estimates represents the net
savings from the CC>2 standards. Note that the total number of miles that vehicles are driven
each year is different under each of the control case scenarios than in the reference case due to
the "rebound effect," which is discussed in Chapter 9. EPA also notes that drivers who drive
more than our average estimates for vehicle miles traveled (VMT) will experience more fuel
savings; drivers who drive less than our average VMT estimates will experience less fuel
savings.
The expected impacts on fuel consumption are shown in Table 7-8. The gallons shown in
this table reflect impacts from the new CC>2 standards and include increased consumption
resulting from the rebound effect.
Table 7-8 Fuel Consumption Reductions of the Proposal (Million gallons)
YEAR
2012
2013
2014
2015
2016
2017
2018
2020
2030
2040
2050
GASOLINE
HD
PICKUPS
&VANS
0.0
0.0
1.8
5.2
15
31
60
114
310
421
507
voc
0.0
0.0
0.0
0.0
5.5
11
16
26
63
75
96
COMB
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
TOTAL
0.0
0.0
1.8
5.2
20
42
76
140
373
496
603
DIESEL
HD
PICKUPS
&VANS
0.0
0.0
5.0
12
30
57
106
199
529
715
862
VOC
0.0
0.0
48
93
136
221
301
445
953
1,483
2,008
COMB
0.0
0.0
264
519
765
1,115
1,454
2,079
3,930
4,805
5,583
TOTAL
0.0
0.0
316
624
931
1,393
1,861
2,723
5,412
7,004
8,453
7-6
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Cost per Ton
7.3.2 Monetized Fuel Savings
Using the fuel consumption estimates presented above, the agencies can calculate the
monetized fuel savings associated with the proposed standards. To do this, reduced fuel
consumption is multiplied in each year by the corresponding estimated average fuel price in that
year, using the reference case taken from the AEO 2010. These estimates do not account for the
significant uncertainty in future fuel prices; the monetized fuel savings will be understated if
actual fuel prices are higher (or overstated if fuel prices are lower) than estimated. The Annual
Energy Outlook (AEO) is a standard reference used by NHTSA and EPA and many other
government agencies to estimate the projected price of fuel. This has been done using both the
pre-tax and post-tax fuel prices. Since the post-tax fuel prices are the prices paid at fuel pumps,
the fuel savings calculated using these prices represent the savings consumers would see. The
pre-tax fuel savings are those savings that society would see. These results are shown in Table
7-9. Note that in Chapter 9, the overall benefits and costs of the rule are presented and, for that
reason, only the pre-tax fuel savings are presented there.
Table 7-9 Estimated Monetized Fuel Savings (SMillions of 2008 dollars)
YEAR
2014
2015
2016
2017
2018
2020
2030
2040
2050
NPV, 3%
NPV, 7%
FUEL SAVINGS (PRE-TAX)
$700
$1,400
$2,200
$3,600
$5,100
$8,100
$19,000
$28,100
$35,400
$352,300
$152,600
FUEL SAVINGS (POST-TAX)
$800
$1,700
$2,700
$4,200
$5,900
$9,300
$21,200
$30,800
$38,400
$391,200
$170,600
7.4 Key Parameters Used in the Estimation of Costs and Fuel Savings
This section briefly presents some of the parameters used in generating costs and fuel
savings associated with the proposal. Table 7-10 presents estimated sales of complying
vehicles by calendar year. Table 7-11 presents VMT by age for both the reference and control
cases where the control case includes rebound VMT. Table 7-12 presents AEO 2010 reference
case fuel prices.
7-7
-------
Draft Regulatory Impact Analysis
Table 7-10 Estimated Calendar Year Sales by Truck Type
Calendar Year
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
HD Pickup Trucks
&Vans
785,224
730,253
712,729
708,456
716,957
704,550
690,599
681,055
673,953
677,291
686,412
699,525
705,204
708,467
707,309
701,934
712,494
717,910
723,365
728,866
734,401
739,983
745,610
751,277
756,984
762,738
768,538
774,377
780,262
786,193
792,165
798,187
804,251
810,366
816,526
822,727
828,980
Vocational
Vehicles
554,944
572,641
591,876
611,137
630,101
648,241
665,920
680,838
695,073
712,386
732,078
752,320
772,814
793,455
814,131
835,498
858,568
943,009
967,709
994,722
,021,818
,050,049
,079,070
,108,902
,139,565
,171,088
,203,492
,236,803
,271,045
,306,246
,342,427
,379,623
,417,862
,457,166
,497,578
,539,108
,581,806
Combination
Tractors
122,156
124,351
126,440
128,766
131,577
134,620
137,301
139,145
140,712
142,742
145,195
147,728
150,169
152,401
154,387
156,312
158,403
160,297
162,090
164,132
166,274
168,696
171,153
173,645
176,174
178,740
181,343
183,984
186,664
189,382
192,140
194,938
197,778
200,658
203,580
206,544
209,553
Total
,462,324
,427,245
,431,046
,448,359
,478,635
,487,411
,493,820
,501,038
,509,737
,532,419
,563,686
,599,573
,628,186
,654,323
,675,827
,693,743
,729,465
,821,216
,853,165
,887,720
,922,493
,958,728
,995,832
2,033,824
2,072,723
2,112,566
2,153,373
2,195,163
2,237,970
2,281,821
2,326,732
2,372,748
2,419,890
2,468,190
2,517,684
2,568,379
2,620,338
7-S
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Cost per Ton
Table 7-11 Annual Vehicle Miles Traveled by Age for the Reference and Control Cases
Vehicle
Age
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Reference
HD Pickup
Tracks & Vans
13,518
13,412
13,263
13,072
12,838
12,569
12,270
11,945
11,593
11,216
10,817
10,405
9,986
9,566
9,152
8,747
8,355
8,037
7,741
7,470
7,227
7,020
6,853
6,733
6,669
6,661
6,707
6,765
6,824
6,884
6,946
Vocational
Vehicles
20,762
19,092
17,552
16,118
14,804
13,586
12,472
11,428
10,489
9,650
8,936
8,263
7,659
7,126
6,626
6,168
5,747
5,368
5,050
4,741
4,436
4,202
3,972
3,773
3,581
3,397
3,239
3,118
2,967
2,853
2,766
Combination
Tractors
137,756
127,350
117,323
107,887
99,347
91,299
83,394
75,595
68,476
62,087
56,300
51,145
46,367
41,939
37,762
34,079
30,738
27,800
25,019
22,587
20,369
18,486
16,700
15,078
13,619
12,294
11,101
10,044
9,089
8,202
7,417
Control
HD Pickup
Tracks & Vans
13,655
13,547
13,397
13,204
12,967
12,696
12,394
12,066
11,711
11,330
10,926
10,510
10,086
9,663
9,244
8,835
8,439
8,118
7,820
7,546
7,300
7,090
6,922
6,801
6,736
6,728
6,775
6,833
6,893
6,954
7,016
Vocational
Vehicles
20,892
19,212
17,661
16,218
14,896
13,670
12,549
11,499
10,554
9,710
8,991
8,313
7,705
7,170
6,667
6,205
5,782
5,401
5,080
4,769
4,463
4,227
3,995
3,795
3,603
3,417
3,258
3,136
2,984
2,869
2,782
Combination
Tractors
138,734
128,254
118,157
108,653
100,052
91,947
83,986
76,132
68,962
62,528
56,700
51,508
46,697
42,237
38,030
34,321
30,956
27,998
25,197
22,748
20,514
18,618
16,818
15,185
13,716
12,381
11,179
10,116
9,153
8,260
7,470
7-9
-------
Draft Regulatory Impact Analysis
Table 7-12 AEO 2010 Reference Case Fuel Prices (2008 dollars/gallon)
Vehicle Age
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
Pre-Tax
Gasoline
$2.61
$2.67
$2.74
$2.81
$2.86
$2.90
$2.95
$2.98
$3.03
$3.06
$3.08
$3.12
$3.16
$3.20
$3.25
$3.30
$3.32
$3.36
$3.41
$3.45
$3.49
$3.56
$3.59
$3.62
$3.65
$3.68
$3.71
$3.74
$3.77
$3.80
$3.83
$3.86
$3.89
$3.92
$3.95
$3.98
$4.01
Diesel
$2.61
$2.71
$2.82
$2.90
$2.99
$3.05
$3.09
$3.12
$3.17
$3.20
$3.21
$3.25
$3.29
$3.33
$3.37
$3.43
$3.46
$3.52
$3.58
$3.62
$3.68
$3.75
$3.76
$3.78
$3.79
$3.81
$3.82
$3.83
$3.85
$3.86
$3.88
$3.89
$3.91
$3.92
$3.94
$3.95
$3.97
Post-Tax
Gasoline
$3.02
$3.07
$3.14
$3.20
$3.25
$3.29
$3.34
$3.37
$3.41
$3.44
$3.45
$3.49
$3.53
$3.57
$3.62
$3.66
$3.68
$3.72
$3.77
$3.80
$3.85
$3.91
$3.94
$3.97
$3.99
$4.02
$4.05
$4.08
$4.11
$4.13
$4.16
$4.19
$4.22
$4.25
$4.28
$4.31
$4.34
Diesel
$3.05
$3.14
$3.24
$3.32
$3.41
$3.47
$3.51
$3.53
$3.58
$3.60
$3.61
$3.65
$3.68
$3.71
$3.76
$3.81
$3.83
$3.89
$3.94
$3.99
$4.04
$4.11
$4.12
$4.13
$4.14
$4.15
$4.17
$4.18
$4.19
$4.20
$4.21
$4.23
$4.24
$4.25
$4.26
$4.28
$4.29
7-10
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Vehicle Cost per Ton
References
1 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards; Final
Rule 75 Fed. Reg. 25323 (May 7, 2010).
2 "Draft Supporting Statement for Information Collection Request," Control of Greenhouse Gas Emissions from
New Motor Vehicles: Proposed Heavy-Duty Engine and Vehicle Standards, EPA ICR Tracking Number 2394.01.
7-11
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Environmental and Health
Impacts
Chapter 8: Health and Environmental Impacts
8.1 Health and Environmental Effects of Non-GHG Pollutants
8.1.1 Health Effects Associated with Exposure to Non-GHG Pollutants
In this section we will discuss the health effects associated with non-GHG pollutants,
specifically: particulate matter, ozone, nitrogen oxides (NOx), sulfur oxides (SOx), carbon
monoxide and air toxics. These pollutants would not be directly regulated by the standards, but
the standards would affect emissions of these pollutants and precursors. Reductions in these
pollutants would be co-benefits of the final rulemaking (that is, benefits in addition to the
benefits of reduced GHGs).
8.1.1.1 Background on Particulate Matter
Particulate matter (PM) is a generic term for a broad class of chemically and physically
diverse substances. It can be principally characterized as discrete particles that exist in the
condensed (liquid or solid) phase spanning several orders of magnitude in size. Since 1987, EPA
has delineated that subset of inhalable particles small enough to penetrate to the thoracic region
(including the tracheobronchial and alveolar regions) of the respiratory tract (referred to as
thoracic particles). Current National Ambient Air Quality Standards (NAAQS) use PM2.5 as the
indicator for fine particles (with PM2.5 referring to particles with a nominal mean aerodynamic
diameter less than or equal to 2.5 jim), and use PMio as the indicator for purposes of regulating
the coarse fraction of PMio (referred to as thoracic coarse particles or coarse-fraction particles;
generally including particles with a nominal mean aerodynamic diameter greater than 2.5 jim
and less than or equal to 10 jim, or PM 10-2.5). Ultrafine particles (UFPs) are a subset of fine
particles, generally less than 100 nanometers (0.1 um) in aerodynamic diameter.
Particles span many sizes and shapes and consist of numerous different chemicals.
Particles originate from sources and are also formed through atmospheric chemical reactions; the
former are often referred to as "primary" particles, and the latter as "secondary" particles. In
addition, there are also physical, non-chemical reaction mechanisms that contribute to secondary
particles. Particle pollution also varies by time of year and location and is affected by several
weather-related factors, such as temperature, clouds, humidity, and wind. A further layer of
complexity comes from a particle's ability to shift between solid/liquid and gaseous phases,
which is influenced by concentration, meteorology, and temperature.
Fine particles are produced primarily by combustion processes and by transformations of
gaseous emissions (e.g., SOx, NOx and volatile organic compounds (VOCs)) in the atmosphere.
The chemical and physical properties of PM2.5 may vary greatly with time, region, meteorology
and source category. Thus, PM2.s may include a complex mixture of different chemicals
including sulfates, nitrates, organic compounds, elemental carbon and metal compounds. These
particles can remain in the atmosphere for days to weeks and travel through the atmosphere
hundreds to thousands of kilometers.1
3-1
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Draft Regulatory Impact Analysis
8.1.1.2 Particulate Matter Health Effects
This section provides a summary of the health effects associated with exposure to
ambient concentrations of PM.A The information in this section is based on the information and
conclusions in the Integrated Science Assessment (ISA) for Particulate Matter (December 2009)
prepared by EPA's Office of Research and Development (ORD).B
The ISA concludes that ambient concentrations of PM are associated with a number of
/-i
adverse health effects. The ISA characterizes the weight of evidence for different health effects
associated with three PM size ranges: PM2.s, PMio-2.5, and UFPs. The discussion below
highlights the ISA's conclusions pertaining to these three size fractions of PM, considering
variations in both short-term and long-term exposure periods.
8.1.1.2.1 Effects Associated with Short-term Exposure to PM2.s
The ISA concludes that cardiovascular effects and all-cause cardiovascular- and
respiratory-related mortality are causally associated with short-term exposure to PM2.s.2 It also
concludes that respiratory effects are likely to be causally associated with short-term exposure to
PM2.5, including respiratory emergency department (ED) visits and hospital admissions for
chronic obstructive pulmonary disease (COPD), respiratory infections, and asthma; and
exacerbation of respiratory symptoms in asthmatic children.
8.1.1.2.2 Effects Associated with Long-term Exposure to PM2.s
The ISA concludes that there are causal associations between long-term exposure to
PM2.5 and cardiovascular effects, such as the development/progression of cardiovascular disease
(CVD), and premature mortality, particularly from cardiopulmonary causes.3 It also concludes
that long-term exposure to PM2.5 is likely to be causally associated with respiratory effects, such
as reduced lung function growth, increased respiratory symptoms, and asthma development. The
ISA characterizes the evidence as suggestive of a causal relationship for associations between
long-term PM2.5 exposure and reproductive and developmental outcomes, such as low birth
weight and infant mortality. It also characterizes the evidence as suggestive of a causal
relationship between PM2.5 and cancer incidence, mutagenicity, and genotoxicity.
8.1.1.2.3 Effects Associated with PM10_25
The ISA summarizes evidence related to short-term exposure to PM 10-2.5. PMio-2.5 is the
fraction of PMio particles that is larger than PM2.5.4 The ISA concludes that available evidence
A Personal exposure includes contributions from many different types of particles, from many sources, and in many
different environments. Total personal exposure to PM includes both ambient and nonambient components; and
both components may contribute to adverse health effects.
B The ISA is available at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546
c The ISA evaluates the health evidence associated with different health effects, assigning one of five "weight of
evidence" determinations: causal relationship, likely to be a causal relationship, suggestive of a causal relationship,
inadequate to infer a causal relationship, and not likely to be a causal relationship. For definitions of these levels of
evidence, please refer to Section 1.5 of the ISA.
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is suggestive of a causal relationship between short-term exposures to PMio-2.5 and
cardiovascular effects, such as hospitalizations for ischemic heart disease. It also concludes that
the available evidence is suggestive of a causal relationship between short-term exposures to
PMio-2.5 and respiratory effects, including respiratory-related ED visits and hospitalizations and
pulmonary inflammation. The ISA also concludes that the available literature suggests a causal
relationship between short-term exposures to PM 10-2.5 and mortality. Data are inadequate to
draw conclusions regarding health effects associated with long-term exposure to PMio-2.5.5
8.1.1.2.4 Effects Associated with Ultrafme Particles
The ISA concludes that the evidence is suggestive of a causal relationship between short-
term exposures to UFPs and cardiovascular effects, including changes in heart rhythm and
vasomotor function (the ability of blood vessels to expand and contract).6
The ISA also concludes that there is suggestive evidence of a causal relationship between
short-term UFP exposure and respiratory effects. The types of respiratory effects examined in
epidemiologic studies include respiratory symptoms and asthma hospital admissions, the results
of which are not entirely consistent. There is evidence from toxicological and controlled human
exposure studies that exposure to UFPs may increase lung inflammation and produce small
asymptomatic changes in lung function. Data are inadequate to draw conclusions regarding
health effects associated with long-term exposure to UFPs.7
8.1.1.3 Background on Ozone
Ground-level ozone pollution is typically formed by the reaction of VOCs and NOx in
the lower atmosphere in the presence of sunlight. These pollutants, often referred to as ozone
precursors, are emitted by many types of pollution sources such as highway and nonroad motor
vehicles and engines, power plants, chemical plants, refineries, makers of consumer and
commercial products, industrial facilities, and smaller area sources.
The science of ozone formation, transport, and accumulation is complex. Ground-level
ozone is produced and destroyed in a cyclical set of chemical reactions, many of which are
sensitive to temperature and sunlight. When ambient temperatures and sunlight levels remain
high for several days and the air is relatively stagnant, ozone and its precursors can build up and
result in more ozone than typically occurs on a single high-temperature day. Ozone can be
transported hundreds of miles downwind of precursor emissions, resulting in elevated ozone
levels even in areas with low VOC or NOx emissions.
The highest levels of ozone are produced when both VOC and NOx emissions are
present in significant quantities on clear summer days. Relatively small amounts of NOx enable
ozone to form rapidly when VOC levels are relatively high, but ozone production is quickly
limited by removal of the NOx. Under these conditions NOx reductions are highly effective in
reducing ozone while VOC reductions have little effect. Such conditions are called "NOx-
limited." Because the contribution of VOC emissions from biogenic (natural) sources to local
ambient ozone concentrations can be significant, even some areas where man-made VOC
emissions are relatively low can be NOx-limited.
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Ozone concentrations in an area also can be lowered by the reaction of nitric oxide (NO)
with ozone, forming nitrogen dioxide (NO2); as the air moves downwind and the cycle
continues, the NO2 forms additional ozone. The importance of this reaction depends, in part, on
the relative concentrations of NOx, VOC, and ozone, all of which change with time and location.
When NOx levels are relatively high and VOC levels relatively low, NOx forms inorganic
nitrates (i.e., particles) but relatively little ozone. Such conditions are called "VOC-limited."
Under these conditions, VOC reductions are effective in reducing ozone, but NOx reductions can
actually increase local ozone under certain circumstances. Even in VOC-limited urban areas,
NOx reductions are not expected to increase ozone levels if the NOx reductions are sufficiently
large. Rural areas are usually NOx-limited, due to the relatively large amounts of biogenic VOC
emissions in such areas. Urban areas can be either VOC- or NOx-limited, or a mixture of both,
in which ozone levels exhibit moderate sensitivity to changes in either pollutant.
8.1.1.4 Ozone Health Effects
Exposure to ambient ozone contributes to a wide range of adverse health effects.0 These
health effects are well documented and are critically assessed in the EPA ozone air quality
criteria document (ozone AQCD) and EPA staff paper.8'9 We are relying on the data and
conclusions in the ozone AQCD and staff paper, regarding the health effects associated with
ozone exposure.
Ozone-related health effects include lung function decrements, respiratory symptoms,
aggravation of asthma, increased hospital and emergency room visits, increased asthma
medication usage, and a variety of other respiratory effects. Cellular-level effects, such as
inflammation of lungs, have been documented as well. In addition, there is suggestive evidence
of a contribution of ozone to cardiovascular-related morbidity and highly suggestive evidence
that short-term ozone exposure directly or indirectly contributes to non-accidental and
cardiopulmonary-related mortality, but additional research is needed to clarify the underlying
mechanisms causing these effects. In a recent report on the estimation of ozone-related
premature mortality published by the National Research Council (NRC), a panel of experts and
reviewers concluded that short-term exposure to ambient ozone is likely to contribute to
premature deaths and that ozone-related mortality should be included in estimates of the health
benefits of reducing ozone exposure.10 People who appear to be more susceptible to effects
associated with exposure to ozone include children, asthmatics and the elderly. Those with
greater exposures to ozone, for instance due to time spent outdoors (e.g., children and outdoor
workers), are also of concern.
Based on a large number of scientific studies, EPA has identified several key health
effects associated with exposure to levels of ozone found today in many areas of the country.
D Human exposure to ozone varies over time due to changes in ambient ozone concentration and because people
move between locations which have notable different ozone concentrations. Also, the amount of ozone delivered to
the lung is not only influenced by the ambient concentrations but also by the individuals breathing route and rate.
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Short-term (1 to 3 hours) and prolonged exposures (6 to 8 hours) to ambient ozone
concentrations have been linked to lung function decrements, respiratory symptoms, increased
hospital admissions and emergency room visits for respiratory problems.11'12'13'14'15'16
Repeated exposure to ozone can increase susceptibility to respiratory infection and lung
inflammation and can aggravate preexisting respiratory diseases, such as asthma.17'18'19'20'21
Repeated exposure to sufficient concentrations of ozone can also cause inflammation of the lung,
impairment of lung defense mechanisms, and possibly irreversible changes in lung structure,
which over time could affect premature aging of the lungs and/or the development of chronic
respiratory illnesses, such as emphysema and chronic bronchitis.22'23'24' 25
Children and adults who are outdoors and active during the summer months, such as
96
construction workers, are among those most at risk of elevated ozone exposures. Children and
outdoor workers tend to have higher ozone exposure because they typically are active outside,
working, playing and exercising, during times of day and seasons (e.g., the summer) when ozone
levels are highest.27 For example, summer camp studies in the Eastern United States and
Southeastern Canada have reported statistically significant reductions in lung function in
children who are active outdoors.28' 29'30'31'32'33'34'35 Further, children are more at risk of
experiencing health effects from ozone exposure than adults because their respiratory systems
are still developing. These individuals (as well as people with respiratory illnesses, such as
asthma, especially asthmatic children) can experience reduced lung function and increased
respiratory symptoms, such as chest pain and cough, when exposed to relatively low ozone levels
during prolonged periods of moderate exertion.36'37'38'39
8.1.1.5 Background on Nitrogen Oxides and Sulfur Oxides
Sulfur dioxide (862), a member of the sulfur oxide (SOx) family of gases, is formed
from burning fuels containing sulfur (e.g., coal or oil), extracting gasoline from oil, or extracting
metals from ore. Nitrogen dioxide (NCh) is a member of the nitrogen oxide (NOx) family of
gases. Most NO2 is formed in the air through the oxidation of nitric oxide (NO) emitted when
fuel is burned at a high temperature. 862 andNC>2 can dissolve in water droplets and further
oxidize to form sulfuric and nitric acid which react with ammonia to form sulfates and nitrates,
both of which are important components of ambient PM. The health effects of ambient PM are
discussed in Section 8.1.1.2. NOx along with non-methane hydrocarbons (NMHC) are the two
major precursors of ozone. The health effects of ozone are covered in Section 8.1.1.4.
8.1.1.6 Health Effects of SO2
This section provides an overview of the health effects associated with SO2. Additional
information on the health effects of SO2 can be found in the EPA Integrated Science Assessment
for Sulfur Oxides.40 Following an extensive evaluation of health evidence from epidemiologic
and laboratory studies, the U.S. EPA has concluded that there is a causal relationship between
respiratory health effects and short-term exposure to SO2. The immediate effect of SO2 on the
respiratory system in humans is bronchoconstriction. Asthmatics are more sensitive to the effects
of SO2 likely resulting from preexisting inflammation associated with this disease. In laboratory
studies involving controlled human exposures to SO2, respiratory effects have consistently been
observed following 5-10 min exposures at SO2 concentrations > 0.4 ppm in asthmatics engaged
in moderate to heavy levels of exercise, with more limited evidence of respiratory effects among
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exercising asthmatics exposed to concentrations as low as 0.2-0.3 ppm. A clear concentration-
response relationship has been demonstrated in these studies following exposures to 862 at
concentrations between 0.2 and 1.0 ppm, both in terms of increasing severity of respiratory
symptoms and decrements in lung function, as well as the percentage of asthmatics adversely
affected.
In epidemiologic studies, respiratory effects have been observed in areas where the mean
24-hour SC>2 levels range from 1 to 30 ppb, with maximum 1 to 24-hour average SC>2 values
ranging from 12 to 75 ppb. Important new multicity studies and several other studies have found
an association between 24-hour average ambient SO2 concentrations and respiratory symptoms
in children, particularly those with asthma. Generally consistent associations also have been
observed between ambient 862 concentrations and emergency department visits and
hospitalizations for all respiratory causes, particularly among children and older adults (> 65
years), and for asthma. A limited subset of epidemiologic studies have examined potential
confounding by copollutants using multipollutant regression models. These analyses indicate
that although copollutant adjustment has varying degrees of influence on the 862 effect
estimates, the effect of SC>2 on respiratory health outcomes appears to be generally robust and
independent of the effects of gaseous and particulate copollutants, suggesting that the observed
effects of SC>2 on respiratory endpoints occur independent of the effects of other ambient air
pollutants.
Consistent associations between short-term exposure to SC>2 and mortality have been
observed in epidemiologic studies, with larger effect estimates reported for respiratory mortality
than for cardiovascular mortality. While this finding is consistent with the demonstrated effects
of 862 on respiratory morbidity, uncertainty remains with respect to the interpretation of these
associations due to potential confounding by various copollutants. The U.S. EPA has therefore
concluded that the overall evidence is suggestive of a causal relationship between short-term
exposure to 862 and mortality. Significant associations between short-term exposure to 862
and emergency department visits and hospital admissions for cardiovascular diseases have also
been reported. However, these findings have been inconsistent across studies and do not provide
adequate evidence to infer a causal relationship between SO2 exposure and cardiovascular
morbidity.
8.1.1.7 Health Effects ofNO2
Information on the health effects of NO2 can be found in the EPA Integrated Science
Assessment (ISA) for Nitrogen Oxides.41 The EPA has concluded that the findings of
epidemiologic, controlled human exposure, and animal toxicological studies provide evidence
that is sufficient to infer a likely causal relationship between respiratory effects and short-term
NO2 exposure. The ISA concludes that the strongest evidence for such a relationship comes from
epidemiologic studies of respiratory effects including symptoms, emergency department visits,
and hospital admissions. The ISA also draws two broad conclusions regarding airway
responsiveness following NC>2 exposure. First, the ISA concludes that NC>2 exposure may
enhance the sensitivity to allergen-induced decrements in lung function and increase the
allergen-induced airway inflammatory response following 30-minute exposures of asthmatics to
NC>2 concentrations as low as 0.26 ppm. In addition, small but significant increases in non-
specific airway hyperresponsiveness were reported following 1-hour exposures of asthmatics to
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0.1 ppm NO2. Second, exposure to NO2 has been found to enhance the inherent responsiveness
of the airway to subsequent nonspecific challenges in controlled human exposure studies of
asthmatic subjects. Enhanced airway responsiveness could have important clinical implications
for asthmatics since transient increases in airway responsiveness following NC>2 exposure have
the potential to increase symptoms and worsen asthma control. Together, the epidemiologic and
experimental data sets form a plausible, consistent, and coherent description of a relationship
between NO2 exposures and an array of adverse health effects that range from the onset of
respiratory symptoms to hospital admission.
Although the weight of evidence supporting a causal relationship is somewhat less certain
than that associated with respiratory morbidity, NC>2 has also been linked to other health
endpoints. These include all-cause (nonaccidental) mortality, hospital admissions or emergency
department visits for cardiovascular disease, and decrements in lung function growth associated
with chronic exposure.
8.1.1.8 Health Effects of Carbon Monoxide
Information on the health effects of carbon monoxide (CO) can be found in the EPA
Integrated Science Assessment (ISA) for Carbon Monoxide.42 The ISA concludes that ambient
concentrations of CO are associated with a number of adverse health effects.E This section
provides a summary of the health effects associated with exposure to ambient concentrations of
CO.F
Human clinical studies of subjects with coronary artery disease show a decrease in the
time to onset of exercise-induced angina (chest pain) and electrocardiogram changes following
CO exposure. In addition, epidemiologic studies show associations between short-term CO
exposure and cardiovascular morbidity, particularly increased emergency room visits and
hospital admissions for coronary heart disease (including ischemic heart disease, myocardial
infarction, and angina). Some epidemiologic evidence is also available for increased hospital
admissions and emergency room visits for congestive heart failure and cardiovascular disease as
a whole. The ISA concludes that a causal relationship is likely to exist between short-term
exposures to CO and cardiovascular morbidity. It also concludes that available data are
inadequate to conclude that a causal relationship exists between long-term exposures to CO and
cardiovascular morbidity.
Animal studies show various neurological effects with in-utero CO exposure. Controlled
human exposure studies report inconsistent neural and behavioral effects following low-level CO
E The ISA evaluates the health evidence associated with different health effects, assigning one of five "weight of
evidence" determinations: causal relationship, likely to be a causal relationship, suggestive of a causal relationship,
inadequate to infer a causal relationship, and not likely to be a causal relationship. For definitions of these levels of
evidence, please refer to Section 1.6 of the ISA.
F Personal exposure includes contributions from many sources, and in many different environments. Total personal
exposure to CO includes both ambient and nonambient components; and both components may contribute to adverse
health effects.
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exposures. The ISA concludes the evidence is suggestive of a causal relationship with both
short- and long-term exposure to CO and central nervous system effects.
A number of epidemiologic and animal toxicological studies cited in the ISA have
evaluated associations between CO exposure and birth outcomes such as preterm birth or cardiac
birth defects. The epidemiologic studies provide limited evidence of a CO-induced effect on
preterm births and birth defects, with weak evidence for a decrease in birth weight. Animal
toxicological studies have found associations between perinatal CO exposure and decrements in
birth weight, as well as other developmental outcomes. The ISA concludes these studies are
suggestive of a causal relationship between long-term exposures to CO and developmental
effects and birth outcomes.
Epidemiologic studies provide evidence of effects on respiratory morbidity such as
changes in pulmonary function, respiratory symptoms, and hospital admissions associated with
ambient CO concentrations. A limited number of epidemiologic studies considered copollutants
such as ozone, SO2, and PM in two-pollutant models and found that CO risk estimates were
generally robust, although this limited evidence makes it difficult to disentangle effects attributed
to CO itself from those of the larger complex air pollution mixture. Controlled human exposure
studies have not extensively evaluated the effect of CO on respiratory morbidity. Animal studies
at levels of 50-100 ppm CO show preliminary evidence of altered pulmonary vascular
remodeling and oxidative injury. The ISA concludes that the evidence is suggestive of a causal
relationship between short-term CO exposure and respiratory morbidity, and inadequate to
conclude that a causal relationship exists between long-term exposure and respiratory morbidity.
Finally, the ISA concludes that the epidemiologic evidence is suggestive of a causal
relationship between short-term exposures to CO and mortality. Epidemiologic studies provide
evidence of an association between short-term exposure to CO and mortality, but limited
evidence is available to evaluate cause-specific mortality outcomes associated with CO exposure.
In addition, the attenuation of CO risk estimates which was often observed in copollutant models
contributes to the uncertainty as to whether CO is acting alone or as an indicator for other
combustion-related pollutants. The ISA also concludes that there is not likely to be a causal
relationship between relevant long-term exposures to CO and mortality.
8.1.1.9 Health Effects of Air Toxics
Motor vehicle emissions contribute to ambient levels of air toxics known or suspected as
human or animal carcinogens, or that have noncancer health effects. The population experiences
an elevated risk of cancer and other noncancer health effects from exposure to air toxics.43
These compounds include, but are not limited to, benzene, 1,3-butadiene, formaldehyde,
acetaldehyde, acrolein, diesel particulate matter and exhaust organic gases, polycyclic organic
matter (POM), and naphthalene. These compounds were identified as national or regional risk
drivers in past National-scale Air Toxics Assessments (NATA) and have significant inventory
contributions from mobile sources. Although the 2002 NATA did not quantify cancer risks
associated with exposure to diesel exhaust, EPA has concluded that diesel exhaust ranks with the
other emissions that the 2002 NATA suggests pose the greatest relative risk. According to
NATA for 2002, mobile sources were responsible for 47 percent of outdoor toxic emissions, over
50 percent of the cancer risk, and over 80 percent of the noncancer hazard. Data from the 2002
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National Emissions Inventory (NEI), which is the basis for NATA, show that thirty percent of
national diesel PM emissions are attributable to heavy-duty vehicles.44
Noncancer health effects can result from chronic,0 subchronic,H or acute1 inhalation
exposures to air toxics, and include neurological, cardiovascular, liver, kidney, and respiratory
effects as well as effects on the immune and reproductive systems. According to the 2002
NATA, nearly the entire U.S. population was exposed to an average concentration of air toxics
that has the potential for adverse noncancer respiratory health effects. This will continue to be
the case in 2030, even though toxics concentrations will be lower.45
The NATA modeling framework has a number of limitations which prevent its use as the
sole basis for setting regulatory standards. These limitations and uncertainties are discussed on
the 2002 NATA website.46 Even so, this modeling framework is very useful in identifying air
toxic pollutants and sources of greatest concern, setting regulatory priorities, and informing the
decision making process.
8.1.1.9.1 Diesel Exhaust PM
Heavy-duty diesel engines emit diesel exhaust (DE), a complex mixture comprised of
carbon dioxide, oxygen, nitrogen, water vapor, carbon monoxide, nitrogen compounds, sulfur
compounds and numerous low-molecular-weight hydrocarbons. A number of these gaseous
hydrocarbon components are individually known to be toxic including aldehydes, benzene and
1,3-butadiene. The diesel paniculate matter (DPM) present in diesel exhaust consists of fine
particles (< 2.5|im), including a subgroup with a large number of ultrafme particles (< 0.1 jim).
These particles have large surface areas which make them an excellent medium for adsorbing
organics, and their small size makes them highly respirable and able to deposit deep in the lung.
Diesel PM contains small quantities of numerous mutagenic and carcinogenic compounds
associated with the particles (and also organic gases). In addition, while toxic trace metals
emitted by heavy-duty diesel engines represent a very small portion of the national emissions of
metals (less than one percent) and are a small portion of diesel PM (generally much less than one
percent of diesel PM), we note that several trace metals of potential toxicological significance
and persistence in the environment are emitted by diesel engines. These trace metals include
chromium, manganese, mercury and nickel. In addition, small amounts of dioxins have been
measured in highway engine diesel exhaust, some of which may partition into the particulate
phase. Dioxins are a major health concern but diesel engines are a minor contributor to overall
dioxin emissions.
G Chronic exposure is defined in the glossary of the Integrated Risk Information (IRIS) database
(http://www.epa.gov/iris) as repeated exposure by the oral, dermal, or inhalation route for more than approximately
10% of the life span in humans (more than approximately 90 days to 2 years in typically used laboratory animal
species).
H Defined in the IRIS database as exposure to a substance spanning approximately 10% of the lifetime of an
organism.
1 Defined in the IRIS database as exposure by the oral, dermal, or inhalation route for 24 hours or less.
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Diesel exhaust varies significantly in chemical composition and particle sizes between
different engine types (heavy-duty, light-duty), engine operating conditions (idle, accelerate,
decelerate), and fuel formulations (high/low sulfur fuel). 4? Also, there are emission differences
between on-road and nonroad engines because the nonroad engines are generally of older
technology. After being emitted, diesel exhaust undergoes dilution as well as chemical and
physical changes in the atmosphere. The lifetime for some of the compounds present in diesel
exhaust ranges from hours to days.
A number of health studies have been conducted regarding diesel exhaust. These include
epidemiologic studies of lung cancer in groups of workers and animal studies focusing on non-
cancer effects specific to diesel exhaust exposure. Diesel exhaust PM (including the associated
organic compounds which are generally high molecular weight hydrocarbon types but not the
more volatile gaseous hydrocarbon compounds) is generally used as a surrogate measure for
diesel exhaust.
8.1.1.9.1.1 Potential Cancer Effects of Exposure to Diesel Exhaust
Exposure to diesel exhaust is of specific concern because it has been judged by EPA to
pose a lung cancer hazard for humans at environmental levels of exposure.
EPA's 2002 final "Health Assessment Document for Diesel Engine Exhaust" (the EPA
Diesel HAD) classified exposure to diesel exhaust as likely to be carcinogenic to humans by
inhalation at environmental exposures, in accordance with the revised draft 1996/1999 EPA
cancer guidelines.48'49 In accordance with earlier EPA guidelines, exposure to diesel exhaust
would similarly be classified as probably carcinogenic to humans (Group Bl).50'51 A number of
other agencies (National Institute for Occupational Safety and Health, the International Agency
for Research on Cancer, the World Health Organization, California EPA, and the U.S.
Department of Health and Human Services) have made similar classifications.52' 53>54>55'56 The
Health Effects Institute has prepared numerous studies and reports on the potential
carcinogenicity of exposure to diesel exhaust.57'58'59
More specifically, the EPA Diesel HAD states that the conclusions of the document apply
to diesel exhaust in use today including both on-road and nonroad engines. The EPA Diesel
HAD acknowledges that the studies were done on engines with generally older technologies and
that "there have been changes in the physical and chemical composition of some DE [diesel
exhaust] emissions (onroad vehicle emissions) over time, though there is no definitive
information to show that the emission changes portend significant toxicological changes."
For the Diesel HAD, EPA reviewed 22 epidemiologic studies on the subject of the
carcinogenicity of exposure to diesel exhaust in various occupations, finding increased lung
cancer risk, although not always statistically significant, in 8 out of 10 cohort studies and 10 out
of 12 case-control studies which covered several industries. Relative risk for lung cancer,
associated with exposure, ranged from 1.2 to 1.5, although a few studies show relative risks as
high as 2.6. Additionally, the Diesel HAD also relied on two independent meta-analyses, which
examined 23 and 30 occupational studies respectively, and found statistically significant
increases of 1.33 to 1.47 in smoking-adjusted relative lung cancer risk associated with diesel
exhaust. These meta-analyses demonstrate the effect of pooling many studies and in this case
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show the positive relationship between diesel exhaust exposure and lung cancer across a variety
of diesel exhaust-exposed occupations.60'61'62
EPA generally derives cancer unit risk estimates to calculate population risk more
precisely from exposure to carcinogens. In the simplest terms, the cancer unit risk is the
increased risk associated with average lifetime exposure of 1 |ig/m3. EPA concluded in the
Diesel HAD that it is not currently possible to calculate a cancer unit risk for diesel exhaust due
to a variety of factors that limit the current studies, such as a lack of standard exposure metric for
diesel exhaust and the absence of quantitative exposure characterization in retrospective studies.
In the absence of a cancer unit risk, the Diesel HAD sought to provide additional insight
into the significance of the diesel exhaust-cancer hazard by estimating possible ranges of risk
that might be present in the population. An exploratory analysis was used to characterize a
possible risk range by comparing a typical environmental exposure level for highway diesel
sources to a selected range of occupational exposure levels. The occupationally observed risks
were then proportionally scaled according to the exposure ratios to obtain an estimate of the
possible environmental risk. If the occupational and environmental exposures are similar, the
environmental risk would approach the risk seen in the occupational studies whereas a much
higher occupational exposure indicates that the environmental risk is lower than the occupational
risk. A comparison of environmental and occupational exposures showed that for certain
occupations the exposures are similar to environmental exposures while, for others, they differ
by a factor of about 200 or more.
A number of calculations are involved in the exploratory analysis of a possible risk range,
and these can be seen in the EPA Diesel HAD. The outcome was that environmental risks from
diesel exhaust exposure could range from a low of 10"4 to 10"5 to as high as 10"3, reflecting the
range of occupational exposures that could be associated with the relative and absolute risk
levels observed in the occupational studies. Because of uncertainties, the analysis acknowledged
that the risks could be lower than 10"4 or 10"5, and a zero risk from diesel exhaust exposure was
not ruled out.
As mentioned in Section 8.1.1.9, EPA recently assessed air toxic emissions and their
associated risk (the National-Scale Air Toxics Assessment or NATA for 2002), and we
concluded that diesel exhaust ranks with other emissions that the national-scale assessment
suggests pose the greatest relative risk.63 This national assessment estimates average population
inhalation exposures to DPM for nonroad as well as on-highway sources. These are the sum of
ambient levels in various locations weighted by the amount of time people spend in each of the
locations.
In summary, even though EPA does not have a specific carcinogenic potency with which
to accurately estimate the carcinogenic impact of exposure to diesel exhaust, the likely hazard to
humans together with the potential for significant environmental risks leads us to conclude that
diesel exhaust emissions from heavy-duty diesel engines present public health issues of concern
to this proposal.
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8.1.1.9.1.2 Other Health Effects of Exposure to Diesel Exhaust
Noncancer health effects of acute and chronic exposure to diesel exhaust emissions are
also of concern to the EPA. The Diesel HAD established an inhalation Reference Concentration
(RfC) specifically based on animal studies of diesel exhaust exposure. An RfC is defined by
EPA as "an estimate of a continuous inhalation exposure to the human population, including
sensitive subgroups, with uncertainty spanning perhaps an order of magnitude, which is likely to
be without appreciable risks of deleterious noncancer effects during a lifetime." EPA derived the
RfC from consideration of four well-conducted chronic rat inhalation studies showing adverse
pulmonary effects.64'65'66'67 The diesel RfC is based on a "no observable adverse effect" level of
144 |ig/m3 that is further reduced by applying uncertainty factors of 3 for interspecies
extrapolation and 10 for human variations in sensitivity. The resulting RfC derived in the Diesel
HAD is 5 |ig/m3 for diesel exhaust as measured by DPM. This RfC does not consider allergenic
effects such as those associated with asthma or immunologic effects. There is growing evidence
that exposure to diesel exhaust can exacerbate these effects, but the exposure-response data is
presently lacking to derive an RfC. The EPA Diesel HAD states, "With DPM [diesel particulate
matter] being a ubiquitous component of ambient PM, there is an uncertainty about the adequacy
of the existing DE [diesel exhaust] noncancer database to identify all of the pertinent DE-caused
noncancer health hazards."
While there have been relatively few human studies associated specifically with the
noncancer impact of exposure to DPM alone, DPM is a component of the ambient particles
studied in numerous epidemiologic studies. The conclusion that health effects associated with
ambient PM in general are relevant to DPM is supported by studies that specifically associate
observable human noncancer health effects with exposure to DPM. As described in the Diesel
HAD, these studies identified some of the same health effects reported for ambient PM, such as
respiratory symptoms (cough, labored breathing, chest tightness, wheezing), and chronic
respiratory disease (cough, phlegm, chronic bronchitis and suggestive evidence for decreases in
pulmonary function). Symptoms of immunological effects such as wheezing and increased
allergenicity are also seen. Studies in rodents, especially rats, show the potential for human
inflammatory effects in the lung and consequential lung tissue damage from chronic diesel
exhaust inhalation exposure. The Diesel HAD concludes "that acute exposure to DE [diesel
exhaust] has been associated with irritation of the eye, nose, and throat, respiratory symptoms
(cough and phlegm), and neurophysiological symptoms such as headache, lightheadedness,
nausea, vomiting, and numbness or tingling of the extremities."68 There is also evidence for an
immunologic effect such as the exacerbation of allergenic responses to known allergens and
asthma-like symptoms.69'70'71
The Diesel HAD briefly summarizes health effects associated with ambient PM and
discusses the PM2.5 NAAQS. There is a much more extensive body of human data, which is also
mentioned earlier in the health effects discussion for PM2.5 (Section 8.1.1.2 of this RIA),
showing a wide spectrum of adverse health effects associated with exposure to ambient PM, of
which diesel exhaust is an important component. The PM2.5 NAAQS is designed to provide
protection from the non-cancer and premature mortality effects of PM2.5 as a whole.
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8.1.1.9.1.3 Ambient Levels of Diesel Exhaust PM
Because DPM is part of overall ambient PM and cannot be easily distinguished from
overall PM, we do not have direct measurements of DPM in the ambient air. DPM
concentrations are estimated using ambient air quality modeling based on DPM emission
inventories. DPM concentrations were recently estimated as part of the 2002 NATA.72 Ambient
impacts of mobile source emissions were predicted using the Assessment System for Population
Exposure Nationwide (ASPEN) dispersion model.
Concentrations of DPM were calculated at the census tract level in the 2002 NATA.
Figure 8-1 below summarizes the distribution of ambient DPM concentrations at the national
scale. The median DPM concentration calculated nationwide is 0.89 ug/m3. Over 30% of the
DPM and diesel exhaust organic gases can be attributed to onroad diesels. A map of ambient
diesel PM concentrations is provided in Figure 8-1. Areas with high median concentrations are
clustered in the Northeast, Great Lake States, California, and the Gulf Coast States, and are also
distributed throughout the rest of the U.S.
2002 NATA
Diesel PM Concentrations (ug/m3)
Cone (ug/m3)
| 0.01 -0.25
| 025-0.50
| 0.50-0.75
3 0.75-1.00
1.00-2.00
• 2.00- 15.00
Figure 8-1 Estimated County Ambient Concentration of Diesel Particulate Matter
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Table 8-1 Distribution of Census Tract Ambient Concentrations of DPM at the National Scale in 2002 NATAa
5th Percentile
25th Percentile
Median
75th Percentile
95th Percentile
Onroad
Contribution to Mean
Nationwide
(ug/m3)
0.21
0.54
0.89
1.34
2.63
31%
Note:
a This table is generated from data contained in the diesel paniculate matter Microsoft Access database file
found in the Tract-Level Ambient Concentration Summaries section of the 2002 NATA webpage
(http://www.epa.gov/ttn/atw/nata2002/tables.html).
8.1.1.9.1.4 Exposure to Diesel Exhaust PM
Exposure of people to diesel exhaust depends on their various activities, the time spent in
those activities, the locations where these activities occur, and the levels of diesel exhaust
pollutants in those locations. The major difference between ambient levels of diesel paniculate
and exposure levels for diesel particulate is that exposure levels account for a person moving
from location to location, the proximity to the emission source, and whether the exposure occurs
in an enclosed environment.
8.1.1.9.1.4.1
Occupational Exposures
Occupational exposures to diesel exhaust from mobile sources can be several orders of
magnitude greater than typical exposures in the non-occupationally exposed population.
Over the years, diesel particulate exposures have been measured for a number of
occupational groups resulting in a wide range of exposures from 2 to 1280 |ig/m3 for a variety of
occupations. As discussed in the Diesel HAD, the National Institute of Occupational Safety and
Health (NIOSH) has estimated a total of 1,400,000 workers are occupationally exposed to diesel
exhaust from on-road and nonroad vehicles.
8.1.1.9.1.4.2 Elevated Concentrations and Ambient Exposures in Mobile Source
Impacted Areas
Regions immediately downwind of highways or truck stops may experience elevated
ambient concentrations of directly-emitted PM2.s from diesel engines. Due to the unique nature
of highways and truck stops, emissions from a large number of diesel engines are concentrated in
a small area. Studies near roadways with high truck traffic indicate higher concentrations of
components of diesel PM than other locations.73'74'75 High ambient particle concentrations have
also been reported near trucking terminals, truck stops, and bus garages.76'77'78 Additional
discussion of exposure and health effects associated with traffic is included below in Section
8.1.1.10.
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8.1.1.9.2 Benzene
The EPA's IRIS database lists benzene as a known human carcinogen (causing leukemia)
by all routes of exposure, and concludes that exposure is associated with additional health
effects, including genetic changes in both humans and animals and increased proliferation of
7Q RO R1
bone marrow cells in mice. ' ' EPA states in its IRIS database that data indicate a causal
relationship between benzene exposure and acute lymphocytic leukemia and suggest a
relationship between benzene exposure and chronic non-lymphocytic leukemia and chronic
lymphocytic leukemia. The International Agency for Research on Carcinogens (IARC) has
determined that benzene is a human carcinogen and the U.S. Department of Health and Human
S'7 81
Services (DHHS) has characterized benzene as a known human carcinogen. '
A number of adverse noncancer health effects including blood disorders, such as
preleukemia and aplastic anemia, have also been associated with long-term exposure to
benzene.84'85 The most sensitive noncancer effect observed in humans, based on current data, is
the depression of the absolute lymphocyte count in blood.86'87 In addition, recent work,
including studies sponsored by the Health Effects Institute (HEI), provides evidence that
biochemical responses are occurring at lower levels of benzene exposure than previously
RR RQ QO Q1
known. ' ' ' EPA's IRIS program has not yet evaluated these new data.
8.1.1.9.3 1,3-Butadiene
EPA has characterized 1,3-butadiene as carcinogenic to humans by inhalation.92'93 The
IARC has determined that 1,3-butadiene is a human carcinogen and the U.S. DHHS has
characterized 1,3-butadiene as a known human carcinogen.9 '95% There are numerous studies
consistently demonstrating that 1,3-butadiene is metabolized into genotoxic metabolites by
experimental animals and humans. The specific mechanisms of 1,3-butadiene-induced
carcinogenesis are unknown; however, the scientific evidence strongly suggests that the
carcinogenic effects are mediated by genotoxic metabolites. Animal data suggest that females
may be more sensitive than males for cancer effects associated with 1,3-butadiene exposure;
there are insufficient data in humans from which to draw conclusions about sensitive
subpopulations. 1,3-butadiene also causes a variety of reproductive and developmental effects in
mice; no human data on these effects are available. The most sensitive effect was ovarian
atrophy observed in a lifetime bioassay of female mice.97
8.1.1.9.4 Formaldehyde
Since 1987, EPA has classified formaldehyde as a probable human carcinogen based on
evidence in humans and in rats, mice, hamsters, and monkeys.98 EPA is currently reviewing
recently published epidemiological data. For instance, research conducted by the National
Cancer Institute (NCI) found an increased risk of nasopharyngeal cancer and
lymphohematopoietic malignancies such as leukemia among workers exposed to
formaldehyde. 9'100 In an analysis of the lymphohematopoietic cancer mortality from an
extended follow-up of these workers, NCI confirmed an association between
lymphohematopoietic cancer risk and peak exposures.101 A recent NIOSH study of garment
workers also found increased risk of death due to leukemia among workers exposed to
formaldehyde.102 Extended follow-up of a cohort of British chemical workers did not find
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evidence of an increase in nasopharyngeal or lymphohematopoietic cancers, but a continuing
statistically significant excess in lung cancers was reported.1 3
In the past 15 years there has been substantial research on the inhalation dosimetry for
formaldehyde in rodents and primates by the CUT Centers for Health Research (formerly the
Chemical Industry Institute of Toxicology), with a focus on use of rodent data for refinement of
the quantitative cancer dose-response assessment.104'105'106 CIIT's risk assessment of
formaldehyde incorporated mechanistic and dosimetric information on formaldehyde. However,
it should be noted that recent research published by EPA indicates that when two-stage modeling
assumptions are varied, resulting dose-response estimates can vary by several orders of
magnitude.107'108'109'110 These findings are not supportive of interpreting the CUT model results
as providing a conservative (health protective) estimate of human risk.m EPA research also
examined the contribution of the two-stage modeling for formaldehyde towards characterizing
the relative weights of key events in the mode-of-action of a carcinogen. For example, the
model-based inference in the published CUT study that formaldehyde's direct mutagenic action
is not relevant to the compound's tumorigenicity was found not to hold under variations of
modeling assumptions.11
Based on the developments of the last decade, in 2004, the working group of the IARC
concluded that formaldehyde is carcinogenic to humans (Group 1), on the basis of sufficient
evidence in humans and sufficient evidence in experimental animals - a higher classification than
previous IARC evaluations. After reviewing the currently available epidemiological evidence,
the IARC (2006) characterized the human evidence for formaldehyde carcinogenicity as
"sufficient," based upon the data on nasopharyngeal cancers; the epidemiologic evidence on
leukemia was characterized as "strong."113 EPA is reviewing the recent work cited above from
the NCI and NIOSH, as well as the analysis by the CUT Centers for Health Research and other
studies, as part of a reassessment of the human hazard and dose-response associated with
formaldehyde.
Formaldehyde exposure also causes a range of noncancer health effects, including
irritation of the eyes (burning and watering of the eyes), nose and throat. Effects from repeated
exposure in humans include respiratory tract irritation, chronic bronchitis and nasal epithelial
lesions such as metaplasia and loss of cilia. Animal studies suggest that formaldehyde may also
cause airway inflammation - including eosinophil infiltration into the airways. There are several
studies that suggest that formaldehyde may increase the risk of asthma - particularly in the
young.114'115
8.1.1.9.5 Acetaldehyde
Acetaldehyde is classified in EPA's IRIS database as a probable human carcinogen,
based on nasal tumors in rats, and is considered toxic by the inhalation, oral, and intravenous
routes.116 Acetaldehyde is reasonably anticipated to be a human carcinogen by the U.S. DHHS
in the 11* Report on Carcinogens and is classified as possibly carcinogenic to humans (Group
2B) by the IARC.117'118 EPA is currently conducting a reassessment of cancer risk from
inhalation exposure to acetaldehyde.
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The primary noncancer effects of exposure to acetaldehyde vapors include irritation of
the eyes, skin, and respiratory tract.119 In short-term (4 week) rat studies, degeneration of
olfactory epithelium was observed at various concentration levels of acetaldehyde
exposure.1 °'121 Data from these studies were used by EPA to develop an inhalation reference
concentration. Some asthmatics have been shown to be a sensitive subpopulation to decrements
in functional expiratory volume (FEV1 test) and bronchoconstriction upon acetaldehyde
199
inhalation. The agency is currently conducting a reassessment of the health hazards from
inhalation exposure to acetaldehyde.
8.1.1.9.6 Acrolein
Acrolein is extremely acrid and irritating to humans when inhaled, with acute exposure
resulting in upper respiratory tract irritation, mucus hypersecretion and congestion. The intense
irritancy of this carbonyl has been demonstrated during controlled tests in human subjects, who
19^
suffer intolerable eye and nasal mucosal sensory reactions within minutes of exposure. These
data and additional studies regarding acute effects of human exposure to acrolein are
summarized in EPA's 2003 IRIS Human Health Assessment for acrolein.m Evidence available
from studies in humans indicate that levels as low as 0.09 ppm (0.21 mg/m3) for five minutes
may elicit subjective complaints of eye irritation with increasing concentrations leading to more
extensive eye, nose and respiratory symptoms.125 Lesions to the lungs and upper respiratory
tract of rats, rabbits, and hamsters have been observed after subchronic exposure to acrolein.126
Acute exposure effects in animal studies report bronchial hyper-responsiveness.127 In a recent
study, the acute respiratory irritant effects of exposure to 1.1 ppm acrolein were more
pronounced in mice with allergic airway disease by comparison to non-diseased mice which also
showed decreases in respiratory rate.128 Based on these animal data and demonstration of similar
effects in humans (e.g., reduction in respiratory rate), individuals with compromised respiratory
function (e.g., emphysema, asthma) are expected to be at increased risk of developing adverse
responses to strong respiratory irritants such as acrolein.
EPA determined in 2003 that the human carcinogenic potential of acrolein could not be
determined because the available data were inadequate. No information was available on the
carcinogenic effects of acrolein in humans and the animal data provided inadequate evidence of
carcinogenicity.129 The IARC determined in 1995 that acrolein was not classifiable as to its
carcinogenicity in humans.130
8.1.1.9.7 Poly cyclic Organic Matter (POM)
POM is generally defined as a large class of organic compounds which have multiple
benzene rings and a boiling point greater than 100 degrees Celsius. Many of the compounds
included in the class of compounds known as POM are classified by EPA as probable human
carcinogens based on animal data. One of these compounds, naphthalene, is discussed separately
below. Polycyclic aromatic hydrocarbons (PAHs) are a subset of POM that contain only
hydrogen and carbon atoms. A number of PAHs are known or suspected carcinogens. Recent
studies have found that maternal exposures to PAHs (a subclass of POM) in a population of
pregnant women were associated with several adverse birth outcomes, including low birth
weight and reduced length at birth, as well as impaired cognitive development at age three.131'132
EPA has not yet evaluated these recent studies.
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8.1.1.9.8 Naphthalene
Naphthalene is found in small quantities in gasoline and diesel fuels. Naphthalene
emissions have been measured in larger quantities in both gasoline and diesel exhaust compared
with evaporative emissions from mobile sources, indicating it is primarily a product of
combustion. EPA released an external review draft of a reassessment of the inhalation
carcinogenicity of naphthalene based on a number of recent animal carcinogenicity studies.133
The draft reassessment completed external peer review.134 Based on external peer review
comments received, additional analyses are being undertaken. This external review draft does
not represent official agency opinion and was released solely for the purposes of external peer
review and public comment. The National Toxicology Program listed naphthalene as
"reasonably anticipated to be a human carcinogen" in 2004 on the basis of bioassays reporting
clear evidence of carcinogenicity in rats and some evidence of carcinogenicity in mice.135
California EPA has released a new risk assessment for naphthalene, and the IARC has
reevaluated naphthalene and re-classified it as Group 2B: possibly carcinogenic to humans.136
Naphthalene also causes a number of chronic non-cancer effects in animals, including abnormal
1 1"7
cell changes and growth in respiratory and nasal tissues.
8.1.1.9.9 Other Air Toxics
In addition to the compounds described above, other compounds in gaseous hydrocarbon
and PM emissions from vehicles would be affected by today's proposed action. Mobile source
air toxic compounds that would potentially be impacted include ethylbenzene, propionaldehyde,
toluene, and xylene. Information regarding the health effects of these compounds can be found
in EPA's IRIS database/
8.1.1.10 Exposure and Health Effects Associated with Traffic
Populations who live, work, or attend school near major roads experience elevated
exposure concentrations to a wide range of air pollutants, as well as higher risks for a number of
adverse health effects. While the previous sections of this RIA have focused on the health
effects associated with individual criteria pollutants or air toxics, this section discusses the
mixture of different exposures near major roadways, rather than the effects of any single
pollutant. As such, this section emphasizes traffic-related air pollution, in general, as the
relevant indicator of exposure rather than any particular pollutant.
Concentrations of many traffic-generated air pollutants are elevated for up to 300-500
meters downwind of roads with high traffic volumes.138 Numerous sources on roads contribute
to elevated roadside concentrations, including exhaust and evaporative emissions, and
resuspension of road dust and tire and brake wear. Concentrations of several criteria and
hazardous air pollutants are elevated near major roads. Furthermore, different semi-volatile
1 U.S. EPA Integrated Risk Information System (IRIS) database is available at: www.epa.gov/iris
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organic compounds and chemical components of particulate matter, including elemental carbon,
organic material, and trace metals, have been reported at higher concentrations near major roads.
Populations near major roads experience greater risk of certain adverse health effects.
The Health Effects Institute published a report on the health effects of traffic-related air
pollution.139 It concluded that evidence is "sufficient to infer the presence of a causal
association" between traffic exposure and exacerbation of childhood asthma symptoms. The
HEI report also concludes that the evidence is either "sufficient" or "suggestive but not
sufficient" for a causal association between traffic exposure and new childhood asthma cases. A
review of asthma studies by Salam et al. (2008) reaches similar conclusions.140 The HEI report
also concludes that there is "suggestive" evidence for pulmonary function deficits associated
with traffic exposure, but concluded that there is "inadequate and insufficient" evidence for
causal associations with respiratory health care utilization, adult-onset asthma, COPD symptoms,
and allergy. A review by Holguin (2008) notes that the effects of traffic on asthma may be
modified by nutrition status, medication use, and genetic factors.141
The HEI report also concludes that evidence is "suggestive" of a causal association
between traffic exposure and all-cause and cardiovascular mortality. There is also evidence of
an association between traffic-related air pollutants and cardiovascular effects such as changes in
heart rhythm, heart attack, and cardiovascular disease. The HEI report characterizes this
evidence as "suggestive" of a causal association, and an independent epidemiological literature
review by Adar and Kaufman (2007) concludes that there is "consistent evidence" linking
traffic-related pollution and adverse cardiovascular health outcomes.142
Some studies have reported associations between traffic exposure and other health
effects, such as birth outcomes (e.g., low birth weight) and childhood cancer. The HEI report
concludes that there is currently "inadequate and insufficient" evidence for a causal association
between these effects and traffic exposure. A review by Raaschou-Nielsen and Reynolds (2006)
concluded that evidence of an association between childhood cancer and traffic-related air
pollutants is weak, but noted the inability to draw firm conclusions based on limited evidence.143
There is a large population in the U.S. living in close proximity of major roads.
According to the Census Bureau's American Housing Survey for 2007, approximately 20 million
residences in the U.S., 15.6% of all homes, are located within 300 feet (91 m) of a highway with
4+ lanes, a railroad, or an airport.144 Therefore, at current population of approximately 309
million, assuming that population and housing are similarly distributed, there are over 48 million
people in the U.S. living near such sources. The HEI report also notes that in two North
American cities, Los Angeles and Toronto, over 40% of each city's population live within 500
meters of a highway or 100 meters of a major road. It also notes that about 33% of each city's
population resides within 50 meters of major roads. Together, the evidence suggests that a large
U.S. population lives in areas with elevated traffic-related air pollution.
People living near roads are often socioeconomically disadvantaged. According to the
2007 American Housing Survey, a renter-occupied property is over twice as likely as an owner-
occupied property to be located near a highway with 4+ lanes, railroad or airport. In the same
survey, the median household income of rental housing occupants was less than half that of
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owner-occupants ($28,921/$59,886). Numerous studies in individual urban areas report higher
levels of traffic-related air pollutants in areas with high minority or poor populations. 145>146'147
Students may also be exposed in situations where schools are located near major roads.
In a study of nine metropolitan areas across the U.S., Appatova et al. (2008) found that on
average greater than 33% of schools were located within 400 m of an Interstate, US, or state
highway, while 12% were located within 100 m.148 The study also found that among the
metropolitan areas studied, schools in the Eastern U.S. were more often sited near major
roadways than schools in the Western U.S.
Demographic studies of students in schools near major roadways suggest that this
population is more likely than the general student population to be of non-white race or Hispanic
ethnicity, and more often live in low socioeconomic status locations.149'150'151 There is some
inconsistency in the evidence, which may be due to different local development patterns and
measures of traffic and geographic scale used in the studies.
8.1.2 Environmental Effects Associated with Exposure to Non-GHG Pollutants
In this section we will discuss the environmental effects associated with non-GHG
pollutants, specifically: paniculate matter, ozone, NOx, SOx and air toxics.
8.1.2.1 Visibility Degradation
Emissions from heavy-duty vehicles contribute to poor visibility in the U.S. through their
emissions of primary PM2.5 and secondary PM2.5 precursors such as NOx. Airborne particles
degrade visibility by scattering and absorbing light. Good visibility increases the quality of life
where individuals live and work, and where they engage in recreational activities.
EPA is pursuing a two-part strategy to address visibility. First, EPA has concluded that
PM2.5 causes adverse effects on visibility in various locations, depending on PM concentrations
and factors such as chemical composition and average relative humidity, and has set secondary
PM2.5 standards.K The secondary PM2.5 standards act in conjunction with the regional haze
program. EPA's regional haze rule (64 FR 35714) was put in place in July 1999 to protect the
visibility in Mandatory Class I Dederal areas. There are 156 national parks, forests and
wilderness areas categorized as Mandatory Class I Federal areas (62 FR 38680-81, July 18,
1997).L Visibility can be said to be impaired in both PM2.s nonattainment areas and mandatory
class I federal areas. Figure 8-2 shows the location of the 156 Mandatory Class I Federal areas.
K The existing annual primary and secondary PM2.5 standards have been remanded and are being addressed in the
currently ongoing PM NAAQS review.
L These areas are defined in CAA section 162 as those national parks exceeding 6,000 acres, wilderness areas and
memorial parks exceeding 5,000 acres, and all international parks which were in existence on August 7, 1977.
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Produced by NPS Air Resources Division
> Rainbow Lake, Wl and Bradwell Gay. FL are Class 1 Areas
where visibility is not an important air quality related value
11.2.1.1
Figure 8-2 Mandatory Class I Federal Areas in the U.S.
Visibility Monitoring
In conjunction with the U.S. National Park Service, the U.S. Forest Service, other Federal
land managers, and State organizations in the U.S., the U.S. EPA has supported visibility
monitoring in national parks and wilderness areas since 1988. The monitoring network was
originally established at 20 sites, but it has now been expanded to 110 sites that represent all but
one of the 156 Mandatory Federal Class I areas across the country (see Figure 8-2). This long-
term visibility monitoring network is known as IMPROVE (Interagency Monitoring of Protected
Visual Environments).
IMPROVE provides direct measurement of fine particles that contribute to visibility
impairment. The IMPROVE network employs aerosol measurements at all sites, and optical and
scene measurements at some of the sites. Aerosol measurements are taken for PMio and PM2.5
mass, and for key constituents of PM2.5, such as sulfate, nitrate, organic and elemental carbon,
soil dust, and several other elements. Measurements for specific aerosol constituents are used to
calculate "reconstructed" aerosol light extinction by multiplying the mass for each constituent by
its empirically-derived scattering and/or absorption efficiency, with adjustment for the relative
humidity. Knowledge of the main constituents of a site's light extinction "budget" is critical for
source apportionment and control strategy development. In addition to this indirect method of
assessing light extinction, there are optical measurements which directly measure light extinction
or its components. Such measurements are taken principally with either a transmissometer,
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which measures total light extinction, or by combining the PM light scattering measured by
integrating nephelometers with the PM light absorption measured by an aethalometer. Scene
characteristics are typically recorded three times daily with 35 millimeter photography and are
used to determine the quality of visibility conditions (such as effects on color and contrast)
associated with specific levels of light extinction as measured under both direct and aerosol-
related methods. Directly measured light extinction is used under the IMPROVE protocol to
cross check that the aerosol-derived light extinction levels are reasonable in establishing current
visibility conditions. Aerosol-derived light extinction is used to document spatial and temporal
trends and to determine how proposed changes in atmospheric constituents would affect future
visibility conditions.
Annual average visibility conditions (reflecting light extinction due to both anthropogenic
and non-anthropogenic sources) vary regionally across the U.S. Visibility is typically worse in
the summer months and the rural East generally has higher levels of impairment than remote
sites in the West. Figures 9-9 through 9-11 in the PM ISA detail the percent contributions to
paniculate light extinction for ammonium nitrate and sulfate, EC and OC, and coarse mass and
fine soil, by season.152
8.1.2.2 Plant and Ecosystem Effects of Ozone
There are a number of environmental or public welfare effects associated with the
presence of ozone in the ambient air.153 In this section we discuss the impact of ozone on plants,
including trees, agronomic crops and urban ornamentals.
The Air Quality Criteria Document for Ozone and related Photochemical Oxidants notes
that, "ozone affects vegetation throughout the United States, impairing crops, native vegetation,
and ecosystems more than any other air pollutant."154 Like carbon dioxide (CO2) and other
gaseous substances, ozone enters plant tissues primarily through apertures (stomata) in leaves in
a process called "uptake."155 Once sufficient levels of ozone (a highly reactive substance), or its
reaction products, reaches the interior of plant cells, it can inhibit or damage essential cellular
components and functions, including enzyme activities, lipids, and cellular membranes,
disrupting the plant's osmotic (i.e., water) balance and energy utilization patterns.156'157 If
enough tissue becomes damaged from these effects, a plant's capacity to fix carbon to form
ICO
carbohydrates, which are the primary form of energy used by plants is reduced, while plant
respiration increases. With fewer resources available, the plant reallocates existing resources
away from root growth and storage, above ground growth or yield, and reproductive processes,
toward leaf repair and maintenance, leading to reduced growth and/or reproduction. Studies
have shown that plants stressed in these ways may exhibit a general loss of vigor, which can lead
to secondary impacts that modify plants' responses to other environmental factors. Specifically,
plants may become more sensitive to other air pollutants, more susceptible to disease, insect
attack, harsh weather (e.g., drought, frost) and other environmental stresses. Furthermore, there
is evidence that ozone can interfere with the formation of mycorrhiza, essential symbiotic fungi
associated with the roots of most terrestrial plants, by reducing the amount of carbon available
for transfer from the host to the symbiont.159'160
This ozone damage may or may not be accompanied by visible injury on leaves, and
likewise, visible foliar injury may or may not be a symptom of the other types of plant damage
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described above. When visible injury is present, it is commonly manifested as chlorotic or
necrotic spots, and/or increased leaf senescence (accelerated leaf aging). Because ozone damage
can consist of visible injury to leaves, it can also reduce the aesthetic value of ornamental
vegetation and trees in urban landscapes, and negatively affects scenic vistas in protected natural
areas.
Ozone can produce both acute and chronic injury in sensitive species depending on the
concentration level and the duration of the exposure. Ozone effects also tend to accumulate over
the growing season of the plant, so that even lower concentrations experienced for a longer
duration have the potential to create chronic stress on sensitive vegetation. Not all plants,
however, are equally sensitive to ozone. Much of the variation in sensitivity between individual
plants or whole species is related to the plant's ability to regulate the extent of gas exchange via
leaf stomata (e.g., avoidance of ozone uptake through closure of stomata)161'162'163 Other
resistance mechanisms may involve the intercellular production of detoxifying substances.
Several biochemical substances capable of detoxifying ozone have been reported to occur in
plants, including the antioxidants ascorbate and glutathione. After injuries have occurred, plants
may be capable of repairing the damage to a limited extent.164
Because of the differing sensitivities among plants to ozone, ozone pollution can also
exert a selective pressure that leads to changes in plant community composition. Given the range
of plant sensitivities and the fact that numerous other environmental factors modify plant uptake
and response to ozone, it is not possible to identify threshold values above which ozone is
consistently toxic for all plants. The next few paragraphs present additional information on
ozone damage to trees, ecosystems, agronomic crops and urban ornamentals.
Ozone also has been conclusively shown to cause discernible injury to forest trees.165'166
In terms of forest productivity and ecosystem diversity, ozone may be the pollutant with the
greatest potential for regional-scale forest impacts. Studies have demonstrated repeatedly that
ozone concentrations commonly observed in polluted areas can have substantial impacts on plant
function.167'168
Because plants are at the base of the food web in many ecosystems, changes to the plant
community can affect associated organisms and ecosystems (including the suitability of habitats
that support threatened or endangered species and below ground organisms living in the root
zone). Ozone impacts at the community and ecosystem level vary widely depending upon
numerous factors, including concentration and temporal variation of tropospheric ozone, species
composition, soil properties and climatic factors.169 In most instances, responses to chronic or
recurrent exposure in forested ecosystems are subtle and not observable for many years. These
injuries can cause stand-level forest decline in sensitive ecosystems. 170>171>172 it is not yet
possible to predict ecosystem responses to ozone with much certainty; however, considerable
knowledge of potential ecosystem responses has been acquired through long-term observations
in highly damaged forests in the United States.
Laboratory and field experiments have also shown reductions in yields for agronomic
crops exposed to ozone, including vegetables (e.g., lettuce) and field crops (e.g., cotton and
wheat). The most extensive field experiments, conducted under the National Crop Loss
Assessment Network (NCLAN) examined 15 species and numerous cultivars. The NCLAN
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results show that "several economically important crop species are sensitive to ozone levels
typical of those found in the United States."173 In addition, economic studies have shown
reduced economic benefits as a result of predicted reductions in crop yields associated with
observed ozone levels.174'175'176
Urban ornamentals represent an additional vegetation category likely to experience some
degree of negative effects associated with exposure to ambient ozone levels. It is estimated that
more than $20 billion (1990 dollars) are spent annually on landscaping using ornamentals, both
by private property owners/tenants and by governmental units responsible for public areas.17?
This is therefore a potentially costly environmental effect. However, in the absence of adequate
exposure-response functions and economic damage functions for the potential range of effects
relevant to these types of vegetation, no direct quantitative analysis has been conducted.
Air pollution can have noteworthy cumulative impacts on forested ecosystems by
1 "7&
affecting regeneration, productivity, and species composition. In the U.S., ozone in the lower
atmosphere is one of the pollutants of primary concern. Ozone injury to forest plants can be
diagnosed by examination of plant leaves. Foliar injury is usually the first visible sign of injury
to plants from ozone exposure and indicates impaired physiological processes in the leaves.179
In the U.S. this indicator is based on data from the U.S. Department of Agriculture
(USDA) Forest Service Forest Inventory and Analysis (FIA) program. As part of its Phase 3
program, formerly known as Forest Health Monitoring, FIA examines ozone injury to ozone-
sensitive plant species at ground monitoring sites in forest land across the country. For this
indicator, forest land does not include woodlots and urban trees. Sites are selected using a
systematic sampling grid, based on a global sampling design.180'181 At each site that has at least
30 individual plants of at least three ozone-sensitive species and enough open space to ensure
that sensitive plants are not protected from ozone exposure by the forest canopy, FIA looks for
damage on the foliage of ozone-sensitive forest plant species. Monitoring of ozone injury to
plants by the USD A Forest Service has expanded over the last 10 years from monitoring sites in
10 states in 1994 to nearly 1,000 monitoring sites in 41 states in 2002.
8.1.2.2.1 Recent Ozone Data for the U.S.
There is considerable regional variation in ozone-related visible foliar injury to sensitive
plants in the U.S. The U.S. EPA has developed an environmental indicator based on data from
the USDA FIA program which examines ozone injury to ozone-sensitive plant species at ground
monitoring sites in forest land across the country (This indicator does not include woodlots and
urban trees). Sites are selected using a systematic sampling grid, based on a global sampling
1 R9 1 R'?
design. ' Because ozone injury is cumulative over the course of the growing season,
examinations are conducted in July and August, when ozone injury is typically highest. The data
underlying the indicator in
Figure 8-3 are based on averages of all observations collected in 2002, the latest year for
which data are publicly available at the time the study was conducted, and are broken down by
U.S. EPA Region. Ozone damage to forest plants is classified using a subjective five-category
biosite index based on expert opinion, but designed to be equivalent from site to site. Ranges of
biosite values translate to no injury, low or moderate foliar injury (visible foliar injury to highly
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sensitive or moderately sensitive plants, respectively), and high or severe foliar injury, which
would be expected to result in tree-level or ecosystem-level responses, respectively.184'185
The highest percentages of observed high and severe foliar injury, those which are most
likely to be associated with tree or ecosystem-level responses, are primarily found in the Mid-
Atlantic and Southeast regions. In EPA Region 3 (which comprises the States of Pennsylvania,
West Virginia, Virginia, Delaware, Maryland and Washington D.C.), 12% of ozone-sensitive
plants showed signs of high or severe foliar damage, and in Regions 2 (States of New York, New
Jersey), and 4 (States of North Carolina, South Carolina, Kentucky, Tennessee, Georgia, Florida,
Alabama, and Mississippi) the values were 10% and 7%, respectively. The sum of high and
severe ozone injury ranged from 2% to 4% in EPA Region 1 (the six New England States),
Region 7 (States of Missouri, Iowa, Nebraska and Kansas), and Region 9 (States of California,
Nevada, Hawaii and Arizona). The percentage of sites showing some ozone damage was about
45% in each of these EPA Regions.
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Draft Regulatory Impact Analysis
Degree ol injury:
None Low Modems Hign Severe
Percent ol monitoring sites in each ca;egc r> •
Ragicn 1
(54 aiteg)
Region 2
[42 sites)
Region 3
|111 sites}
Region 4
(227 sites}
Region 5
(180 sites |
Region 6
: 59 s<:=s (
Region 7
|G3 sites)
Region 3
;72 stesi
Region 9
[30 sitea)
Reoicn "iO
|57 sites)
68.5
16.7
11.1
-3.7
61.9
21.4
71
7.1
5-5.9
ma
7:
45
75.3
1D.t
5-
94.5
-5.1
35.7
9.5
10D.D
76,3
125
3.3
•1.3
•13
:Cowrage: 945 monitoring sites,
Dcated in 41
:Tatala may
raunding
Data Miinw: iSSDA ftjrast Serwos,
am
EPA R&Siont
Figure 8-3 Ozone Injury to Forest Plants in U.S. by EPA Regions, 2002a
8.1.2.2.1.1 Indicator Limitations
Field and laboratory studies were reviewed to identify the forest plant species in each
region that are highly sensitive to ozone air pollution. Other forest plant species, or even genetic
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variants of the same species, may not be harmed at ozone levels that cause effects on the selected
ozone-sensitive species.
Because species distributions vary regionally, different ozone-sensitive plant species
were examined in different parts of the country. These target species could vary with respect to
ozone sensitivity, which might account for some of the apparent differences in ozone injury
among regions of the U.S.
Ozone damage to foliage is considerably reduced under conditions of low soil moisture,
but most of the variability in the index (70%) was explained by ozone concentration.186 Ozone
may have other adverse impacts on plants (e.g., reduced productivity) that do not show signs of
visible foliar injury.18?
Though FIA has extensive spatial coverage based on a robust sample design, not all
forested areas in the U.S. are monitored for ozone injury. Even though the biosite data have been
collected over multiple years, most biosites were not monitored over the entire period, so these
data cannot provide more than a baseline for future trends.
8.1.2.3 Ozone Impacts on Forest Health
Air pollution can impact the environment and affect ecological systems, leading to
changes in the biological community (both in the diversity of species and the health and vigor of
individual species). As an example, many studies have shown that ground-level ozone reduces
the health of plants including many commercial and ecologically important forest tree species
throughout the United States.188
When ozone is present in the air, it can enter the leaves of plants, where it can cause
significant cellular damage. Since photosynthesis occurs in cells within leaves, the ability of the
plant to produce energy by photosynthesis can be compromised if enough damage occurs to
these cells. If enough tissue becomes damaged it can reduce carbon fixation and increase plant
respiration, leading to reduced growth and/or reproduction in young and mature trees. Ozone
stress also increases the susceptibility of plants to disease, insects, fungus, and other
environmental stressors (e.g., harsh weather). Because ozone damage can consist of visible
injury to leaves, it also reduces the aesthetic value of ornamental vegetation and trees in urban
landscapes, and negatively affects scenic vistas in protected natural areas.
Assessing the impact of ground-level ozone on forests in the eastern United States
involves understanding the risks to sensitive tree species from ambient ozone concentrations and
accounting for the prevalence of those species within the forest. As a way to quantify the risks to
particular plants from ground-level ozone, scientists have developed ozone-exposure/tree-
response functions by exposing tree seedlings to different ozone levels and measuring reductions
in growth as "biomass loss." Typically, seedlings are used because they are easy to manipulate
and measure their growth loss from ozone pollution. The mechanisms of susceptibility to ozone
within the leaves of seedlings and mature trees are identical, though the magnitude of the effect
may be higher or lower depending on the tree species. 189
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Some of the common tree species in the United States that are sensitive to ozone are
black cherry (Prunus serotina), tulip-poplar (Liriodendron tulipifera), eastern white pine (Pinus
strobus). Ozone-exposure/tree-response functions have been developed for each of these tree
species, as well as for aspen (Populus tremuliodes), and ponderosa pine (Pinusponderosd).
Other common tree species, such as oak (Quercus spp.j and hickory (Carya spp.), are not nearly
as sensitive to ozone. Consequently, with knowledge of the distribution of sensitive species and
the level of ozone at particular locations, it is possible to estimate a "biomass loss" for each
species across their range.
8.1.2.4 Particulate Matter Deposition
Particulate matter contributes to adverse effects on vegetation and ecosystems, and to
soiling and materials damage. These welfare effects result predominately from exposure to
excess amounts of specific chemical species, regardless of their source or predominant form
(particle, gas or liquid). The following characterizations of the nature of these environmental
effects are based on information contained in the 2009 PM ISA and the 2005 PM Staff Paper as
well as the Integrated Science Assessment for Oxides of Nitrogen and Sulfur- Ecological
Criteria.190'191'192
8.1.2.4.1 Deposition of Nitrogen and Sulfur
Nitrogen and sulfur interactions in the environment are highly complex. Both are
essential, and sometimes limiting, nutrients needed for growth and productivity. Excesses of
nitrogen or sulfur can lead to acidification, nutrient enrichment, and eutrophication of aquatic
193
ecosystems.
The process of acidification affects both freshwater aquatic and terrestrial ecosystems.
Acid deposition causes acidification of sensitive surface waters. The effects of acid deposition
on aquatic systems depend largely upon the ability of the ecosystem to neutralize the additional
acid. As acidity increases, aluminum leached from soils and sediments, flows into lakes and
streams and can be toxic to both terrestrial and aquatic biota. The lower pH concentrations and
higher aluminum levels resulting from acidification make it difficult for some fish and other
aquatic organisms to survive, grow, and reproduce. Research on effects of acid deposition on
forest ecosystems has come to focus increasingly on the biogeochemical processes that affect
uptake, retention, and cycling of nutrients within these ecosystems. Decreases in available base
cations from soils are at least partly attributable to acid deposition. Base cation depletion is a
cause for concern because of the role these ions play in acid neutralization, and because calcium,
magnesium and potassium are essential nutrients for plant growth and physiology. Changes in
the relative proportions of these nutrients, especially in comparison with aluminum
concentrations, have been associated with declining forest health.
At current ambient levels, risks to vegetation from short-term exposures to dry deposited
particulate nitrate or sulfate are low. However, when found in acid or acidifying deposition, such
particles do have the potential to cause direct leaf injury. Specifically, the responses of forest
trees to acid precipitation (rain, snow) include accelerated weathering of leaf cuticular surfaces,
increased permeability of leaf surfaces to toxic materials, water, and disease agents; increased
leaching of nutrients from foliage; and altered reproductive processes—all which serve to
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weaken trees so that they are more susceptible to other stresses (e.g., extreme weather, pests,
pathogens). Acid deposition with levels of acidity associated with the leaf effects described
above are currently found in some locations in the eastern U.S.194 Even higher concentrations of
acidity can be present in occult depositions (e.g., fog, mist or clouds) which more frequently
impacts higher elevations. Thus, the risk of leaf injury occurring from acid deposition in some
areas of the eastern U.S. is high. Nitrogen deposition has also been shown to impact ecosystems
in the western U.S. A study conducted in the Columbia River Gorge National Scenic Area
(CRGNSA), located along a portion of the Oregon/Washington border, indicates that lichen
communities in the CRGNSA have shifted to a higher proportion of nitrophilous species and the
nitrogen content of lichen tissue is elevated.195 Lichens are sensitive indicators of nitrogen
deposition effects to terrestrial ecosystems and the lichen studies in the Columbia River Gorge
clearly show that ecological effects from air pollution are occurring.
Some of the most significant detrimental effects associated with excess nitrogen
deposition are those associated with a condition known as nitrogen saturation. Nitrogen
saturation is the condition in which nitrogen inputs from atmospheric deposition and other
sources exceed the biological requirements of the ecosystem. The effects associated with
nitrogen saturation include: (1) decreased productivity, increased mortality, and/or shifts in plant
community composition, often leading to decreased biodiversity in many natural habitats
wherever atmospheric reactive nitrogen deposition increases significantly above background and
critical thresholds are exceeded; (2) leaching of excess nitrate and associated base cations from
soils into streams, lakes, and rivers, and mobilization of soil aluminum; and (3) fluctuation of
ecosystem processes such as nutrient and energy cycles through changes in the functioning and
species composition of beneficial soil organisms.196
In the U.S. numerous forests now show severe symptoms of nitrogen saturation. These
forests include: the northern hardwoods and mixed conifer forests in the Adirondack and
Catskill Mountains of New York; the red spruce forests at Whitetop Mountain, Virginia, and
Great Smoky Mountains National Park, North Carolina; mixed hardwood watersheds at Fernow
Experimental Forest in West Virginia; American beech forests in Great Smoky Mountains
National Park, Tennessee; mixed conifer forests and chaparral watersheds in southern California
and the southwestern Sierra Nevada in Central California; the alpine tundra/subalpine conifer
forests of the Colorado Front Range; and red alder forests in the Cascade Mountains in
Washington.
Excess nutrient inputs into aquatic ecosystems (i.e. streams, rivers, lakes, estuaries or
oceans) either from direct atmospheric deposition, surface runoff, or leaching from nitrogen
saturated soils into ground or surface waters can contribute to conditions of severe water oxygen
depletion; eutrophication and algae blooms; altered fish distributions, catches, and physiological
states; loss of biodiversity; habitat degradation; and increases in the incidence of disease.
Atmospheric deposition of nitrogen is a significant source of total nitrogen to many
estuaries in the United States. The amount of nitrogen entering estuaries that is ultimately
attributable to atmospheric deposition is not well-defined. On an annual basis, atmospheric
nitrogen deposition may contribute significantly to the total nitrogen load, depending on the size
and location of the watershed. In addition, episodic nitrogen inputs, which may be ecologically
important, may play a more important role than indicated by the annual average concentrations.
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Estuaries in the U.S. that suffer from nitrogen enrichment often experience a condition known as
eutrophication. Symptoms of eutrophication include changes in the dominant species of
phytoplankton, low levels of oxygen in the water column, fish and shellfish kills, outbreaks of
toxic alga, and other population changes which can cascade throughout the food web. In
addition, increased phytoplankton growth in the water column and on surfaces can attenuate light
causing declines in submerged aquatic vegetation, which serves as an important habitat for many
estuarine fish and shellfish species.
Severe and persistent eutrophication often directly impacts human activities. For
example, losses in the nation's fishery resources may be directly caused by fish kills associated
with low dissolved oxygen and toxic blooms. Declines in tourism occur when low dissolved
oxygen causes noxious smells and floating mats of algal blooms create unfavorable aesthetic
conditions. Risks to human health increase when the toxins from algal blooms accumulate in
edible fish and shellfish, and when toxins become airborne, causing respiratory problems due to
inhalation. According to a NOAA report, more than half of the nation's estuaries have moderate
to high expressions of at least one of these symptoms - an indication that eutrophication is well
developed in more than half of U.S. estuaries.1 7
8.1.2.4.2 Deposition of Heavy Metals
Heavy metals, including cadmium, copper, lead, chromium, mercury, nickel and zinc,
have the greatest potential for impacting forest growth.198 Investigation of trace metals near
roadways and industrial facilities indicate that a substantial load of heavy metals can accumulate
on vegetative surfaces. Copper, zinc, and nickel have been documented to cause direct toxicity
to vegetation under field conditions. Little research has been conducted on the effects associated
with mixtures of contaminants found in ambient PM. While metals typically exhibit low
solubility, limiting their bioavailability and direct toxicity, chemical transformations of metal
compounds occur in the environment, particularly in the presence of acidic or other oxidizing
species. These chemical changes influence the mobility and toxicity of metals in the
environment. Once taken up into plant tissue, a metal compound can undergo chemical changes,
exert toxic effects on the plant itself, accumulate and be passed along to herbivores or can re-
enter the soil and further cycle in the environment. Although there has been no direct evidence
of a physiological association between tree injury and heavy metal exposures, heavy metals have
been implicated because of similarities between metal deposition patterns and forest decline.
This hypothesized relationship/correlation was further explored in high elevation forests in the
northeastern U.S. These studies measured levels of a group of intracellular compounds found in
plants that bind with metals and are produced by plants as a response to sublethal concentrations
of heavy metals. These studies indicated a systematic and significant increase in concentrations
of these compounds associated with the extent of tree injury. These data strongly imply that
metal stress causes tree injury and contributes to forest decline in the northeastern United
1 QQ
States. Contamination of plant leaves by heavy metals can lead to elevated soil levels. Trace
metals absorbed into the plant frequently bind to the leaf tissue, and then are lost when the leaf
drops. As the fallen leaves decompose, the heavy metals are transferred into the soil.200'201
Upon entering the soil environment, PM pollutants can alter ecological processes of energy flow
and nutrient cycling, inhibit nutrient uptake, change ecosystem structure, and affect ecosystem
biodiversity. Many of the most important effects occur in the soil. The soil environment is one
of the most dynamic sites of biological interaction in nature. It is inhabited by microbial
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communities of bacteria, fungi, and actinomycetes. These organisms are essential participants in
the nutrient cycles that make elements available for plant uptake. Changes in the soil
environment that influence the role of the bacteria and fungi in nutrient cycling determine plant
and ultimately ecosystem response.202
The environmental sources and cycling of mercury are currently of particular concern due
to the bioaccumulation and biomagnification of this metal in aquatic ecosystems and the potent
toxic nature of mercury in the forms in which is it ingested by people and other animals.
Mercury is unusual compared with other metals in that it largely partitions into the gas phase (in
elemental form), and therefore has a longer residence time in the atmosphere than a metal found
predominantly in the particle phase. This property enables mercury to travel far from the
primary source before being deposited and accumulating in the aquatic ecosystem. The major
source of mercury in the Great Lakes is from atmospheric deposition, accounting for
approximately eighty percent of the mercury in Lake Michigan.203'204 Over fifty percent of the
mercury in the Chesapeake Bay has been attributed to atmospheric deposition.2 5 Overall, the
National Science and Technology Council identifies atmospheric deposition as the primary
source of mercury to aquatic systems.206 Forty-four states have issued health advisories for the
consumption offish contaminated by mercury; however, most of these advisories are issued in
areas without a mercury point source.
Elevated levels of zinc and lead have been identified in streambed sediments, and these
elevated levels have been correlated with population density and motor vehicle use.207'208 Zinc
and nickel have also been identified in urban water and soils. In addition, platinum, palladium,
and rhodium, metals found in the catalysts of modern motor vehicles, have been measured at
elevated levels along roadsides.209 Plant uptake of platinum has been observed at these
locations.
8.1.2.4.3 Deposition of Poly cyclic Organic Matter
Polycyclic organic matter (POM) is a byproduct of incomplete combustion and consists
of organic compounds with more than one benzene ring and a boiling point greater than or equal
to 100 degrees centigrade.210 Polycyclic aromatic hydrocarbons (PAHs) are a class of POM that
contains compounds which are known or suspected carcinogens.
Major sources of PAHs include mobile sources. PAHs in the environment may be
present as a gas or adsorbed onto airborne paniculate matter. Since the majority of PAHs are
adsorbed onto particles less than 1.0 jim in diameter, long range transport is possible. However,
studies have shown that PAH compounds adsorbed onto diesel exhaust particulate and exposed
to ozone have half lives of 0.5 to 1.0 hours.211
Since PAHs are insoluble, the compounds generally are particle reactive and accumulate
in sediments. Atmospheric deposition of particles is believed to be the major source of PAHs to
91991^
the sediments of Lake Michigan. ' Analyses of PAH deposition in Chesapeake and
Galveston Bay indicate that dry deposition and gas exchange from the atmosphere to the surface
water predominate.214'215 Sediment concentrations of PAHs are high enough in some segments
of Tampa Bay to pose an environmental health threat. EPA funded a study to better characterize
o 1 /:
the sources and loading rates for PAHs into Tampa Bay. PAHs that enter a water body
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Draft Regulatory Impact Analysis
through gas exchange likely partition into organic rich particles and can be biologically recycled,
while dry deposition of aerosols containing PAHs tend to be more resistant to biological
recycling.217 Thus, dry deposition is likely the main pathway for PAH concentrations in
sediments while gas/water exchange at the surface may lead to PAH distribution into the food
web, leading to increased health risk concerns.
Trends in PAH deposition levels are difficult to discern because of highly variable
ambient air concentrations, lack of consistency in monitoring methods, and the significant
influence of local sources on deposition levels.218 Van Metre et al. noted PAH concentrations in
urban reservoir sediments have increased by 200-300% over the last forty years and correlate
with increases in automobile use.219
Cousins et al. estimate that more than ninety percent of semi-volatile organic compound
(SVOC) emissions in the United Kingdom deposit on soil.220 An analysis of PAH
concentrations near a Czechoslovakian roadway indicated that concentrations were thirty times
greater than background.221
8.1.2.4.4 Materials Damage and Soiling
The effects of the deposition of atmospheric pollution, including ambient PM, on
materials are related to both physical damage and impaired aesthetic qualities. The deposition of
PM (especially sulfates and nitrates) can physically affect materials, adding to the effects of
natural weathering processes, by potentially promoting or accelerating the corrosion of metals,
by degrading paints, and by deteriorating building materials such as concrete and limestone.
Only chemically active fine particles or hygroscopic coarse particles contribute to these physical
effects. In addition, the deposition of ambient PM can reduce the aesthetic appeal of buildings
and culturally important articles through soiling. Particles consisting primarily of carbonaceous
compounds cause soiling of commonly used building materials and culturally important items
such as statues and works of art.
8.1.2.5 Environmental Effects of Air Toxics
Emissions from producing, transporting and combusting fuel contribute to ambient levels
of pollutants that contribute to adverse effects on vegetation. Volatile organic compounds
(VOCs), some of which are considered air toxics, have long been suspected to play a role in
vegetation damage.222 In laboratory experiments, a wide range of tolerance to VOCs has been
observed.223 Decreases in harvested seed pod weight have been reported for the more sensitive
plants, and some studies have reported effects on seed germination, flowering and fruit ripening.
Effects of individual VOCs or their role in conjunction with other stressors (e.g., acidification,
drought, temperature extremes) have not been well studied. In a recent study of a mixture of
VOCs including ethanol and toluene on herbaceous plants, significant effects on seed production,
99A
leaf water content and photosynthetic efficiency were reported for some plant species.
Research suggests an adverse impact of vehicle exhaust on plants, which has in some
cases been attributed to aromatic compounds and in other cases to nitrogen oxides.225'226'227 The
impacts of VOCs on plant reproduction may have long-term implications for biodiversity and
survival of native species near major roadways. Most of the studies of the impacts of VOCs on
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vegetation have focused on short-term exposure and few studies have focused on long-term
effects of VOCs on vegetation and the potential for metabolites of these compounds to affect
herbivores or insects.
8.2 Air Quality Impacts of Non-GHG Pollutants
8.2.1 Introduction
Chapter 6 of this draft RIA presents the projected emissions changes due to the proposal.
Once the emissions changes are projected the next step is to look at how the ambient air quality
would be impacted by those emissions changes. Although the purpose of this proposal is to
address greenhouse gas emissions, this proposal would also impact emissions of criteria and
hazardous air pollutants. Section 8.2.2 describes current ambient levels of PM, ozone, and some
air toxics without the standards being proposed. No air quality modeling was done for this draft
RIA to project the impacts of the proposal. Air quality modeling will be done for the final
rulemaking, however, and those plans are discussed in Section 8.2.3.
8.2.2 Current Levels of Pollutants
8.2.2.1 Particulate Matter
As described in Section 8.1.1.1, PM causes adverse health effects, and the EPA has set
national standards to provide requisite protection against those health effects. There are two
National Ambient Air Quality Standards (NAAQS) for PM2.5: an annual standard (15 ug/m3) and
a 24-hour standard (35 ug/m3). The most recent revisions to these standards were in 1997 and
2006. In 2005 the U.S. EPA designated nonattainment areas for the 1997 PM2.5 NAAQS (70 FR
19844, April 14, 2005).M As of January 6, 2010, approximately 88 million people live in the 39
areas that are designated as nonattainment for the 1997 PM2.5 NAAQS. These PM2.5
nonattainment areas are comprised of 208 full or partial counties. On October 8, 2009, the EPA
issued final nonattainment area designations for the 2006 24-hour PM2.5 NAAQS (74 FR 58688,
November 13, 2009). These designations include 31 areas composed of 120 full or partial
counties with a population of over 70 million. In total, there are 54 PM2.5 nonattainment areas
composed of 245 counties with a population of 101 million people.
States with PM2.5 nonattainment areas will be required to take action to bring those areas
into compliance in the future. Most 1997 PM2.5 nonattainment areas are required to attain the
1997 PM2.5 NAAQS in the 2010 to 2015 time frame and then required to maintain the 1997
PM2.5 NAAQS thereafter.228 The 2006 24-hour PM2.5 nonattainment areas will be required to
attain the 2006 24-hour PM2.s NAAQS in the 2014 to 2019 time frame and then be required to
maintain the 2006 24-hour PM2.5 NAAQS thereafter.229 The heavy-duty vehicle standards
proposed here first apply to model year 2014 vehicles.
M A nonattainment area is defined in the Clean Air Act (CAA) as an area that is violating an ambient standard or is
contributing to a nearby area that is violating the standard.
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8.2.2.2 Ozone
As described in Section 8.1.1.3, ozone causes adverse health effects, and the EPA has set
national standards to protect against those health effects. The primary and secondary NAAQS
for ozone are 8-hour standards set at 0.075 ppm. The most recent revision to the ozone standards
was in 2008; the previous 8-hour ozone standards, set in 1997, had been set at 0.08 ppm. In
2004, the U.S. EPA designated nonattainment areas for the 1997 8-hour ozone NAAQS (69 FR
23858, April 30, 2004). As of January 6, 2010, there are 51 8-hour ozone nonattainment areas
for the 1997 ozone NAAQS composed of 266 full or partial counties with a total population of
over 122 million. On January 6, 2010, EPA proposed to reconsider the 2008 ozone NAAQS to
ensure that they are requisite to protect public health with an ample margin of safety, and
requisite to protect public welfare. EPA intends to complete the reconsideration by August 31,
2010. If, as a result of the reconsideration, EPA promulgates different ozone standards, the new
2010 ozone standards would replace the 2008 ozone standards and the requirement to designate
areas for the replaced 2008 standards would no longer apply. Because of the significant
uncertainty the reconsideration proposal creates regarding the continued applicability of the 2008
ozone NAAQS, EPA has extended the deadline for designating areas for the 2008 NAAQS by
one year. This will allow EPA to complete its reconsideration of the 2008 ozone NAAQS before
determining whether designations for those standards are necessary.
If EPA promulgates new ozone standards in 2010, EPA intends to accelerate the
designations process for the primary standard so that the designations would be effective in
August 2011. EPA is considering two alternative schedules for designating areas for a new
seasonal secondary standard, an accelerated schedule or a 2-year schedule.
States with ozone nonattainment areas are required to take action to bring those areas into
compliance in the future. The attainment date assigned to an ozone nonattainment area is based
on the area's classification. Most ozone nonattainment areas are required to attain the 1997 8-
hour ozone NAAQS in the 2007 to 2013 time frame and then be required to maintain it
thereafter.N In addition, there will be attainment dates associated with the designation of
nonattainment areas as a result of the reconsideration of the 2008 ozone NAAQS. If the ozone
NAAQS reconsideration action is completed on the proposed schedule, the primary NAAQS
attainment dates would be in the 2014-2031 time frame. The heavy-duty vehicle standards
proposed here first apply to model year 2014 vehicles.
The Los Angeles South Coast Air Basin 8-hour ozone nonattainment area is designated as severe and will have to
attain before June 15, 2021. The South Coast Air Basin has requested to be reclassified as an extreme nonattainment
area which will make their attainment date June 15, 2024. The San Joaquin Valley Air Basin 8-hour ozone
nonattainment area is designated as serious and will have to attain before June 15, 2013. The San Joaquin Valley
Air Basin has requested to be reclassified as an extreme nonattainment area which will make their attainment date
June 15, 2024.
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8.2.2.3 Air Toxics
The majority of Americans continue to be exposed to ambient concentrations of air toxics
at levels which have the potential to cause adverse health effects.230 The levels of air toxics to
which people are exposed vary depending on where people live and work and the kinds of
activities in which they engage, as discussed in detail in U.S. EPA's most recent Mobile Source
Air Toxics (MSAT) Rule. 31 According to the National Air Toxics Assessment (NATA) for
2002, mobile sources were responsible for 47 percent of outdoor toxic emissions and over 50
percent of the cancer risk.232 Nearly the entire U.S. population was exposed to an average
concentration of air toxics that has the potential for adverse noncancer respiratory health effects.
EPA recently finalized vehicle and fuel controls to reduce mobile source air toxics.233 In
addition, over the years, EPA has implemented a number of mobile source and fuel controls
resulting in VOC reductions, which also reduce air toxic emissions. Modeling from the recent
MSAT rule suggests that the mobile source contribution to ambient benzene concentrations is
projected to decrease over 40% by 2015, with a decrease in ambient benzene concentration from
all sources of about 25%. Although benzene is used as an example, the downward trend is
projected for other air toxics as well. See the RIA for the final MSAT rule for more information
on ambient air toxics projections.234
8.2.3 Impacts of Future Air Quality
Air quality models use mathematical and numerical techniques to simulate the physical
and chemical processes that affect air pollutants as they disperse and react in the atmosphere.
Based on inputs of meteorological data and source information, these models are designed to
characterize primary pollutants that are emitted directly into the atmosphere and secondary
pollutants that are formed as a result of complex chemical reactions within the atmosphere.
Photochemical air quality models have become widely recognized and routinely utilized tools for
regulatory analysis by assessing the effectiveness of control strategies. These models are applied
at multiple spatial scales from local, regional, national, and global.
Full-scale photochemical air quality modeling is necessary to accurately project levels of
criteria and air toxic pollutants. For the final rulemaking, a national-scale air quality modeling
analysis will be performed to analyze the impacts of the standards on PM2.5, ozone, and selected
air toxics (i.e., benzene, formaldehyde, acetaldehyde, acrolein and 1,3-butadiene). The length of
time needed to prepare the necessary emissions inventories, in addition to the processing time
associated with the modeling itself, has precluded us from performing air quality modeling for
this proposal.
Section VII of the preamble presents projections of the changes in criteria pollutant and
air toxics emissions due to the proposed standards; the basis for those estimates is set out in
Chapter 6 of the draft RIA. The atmospheric chemistry related to ambient concentrations of
PM2.5, ozone and air toxics is very complex, and making predictions based solely on emissions
changes is extremely difficult. However, based on the magnitude of the emissions changes
predicted to result from the proposed standards, we expect that there will be a relatively small
change in ambient air quality, pending a more comprehensive analysis for the final rulemaking.
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For the final rulemaking, EPA intends to use a 2005-based Community Multi-scale Air
Quality (CMAQ) modeling platform as the tool for the air quality modeling. The CMAQ
modeling system is a comprehensive three-dimensional grid-based Eulerian air quality model
designed to estimate the formation and fate of oxidant precursors, primary and secondary PM
concentrations and deposition, and air toxics, over regional and urban spatial scales (e.g., over
the contiguous U.S.). '236'237 '238 The CMAQ model is a well-known and well-established tool
and is commonly used by EPA for regulatory analyses, for instance the recent ozone NAAQS
proposal, and by States in developing attainment demonstrations for their State Implementation
9^Q
Plans. The CMAQ model version 4.7 was most recently peer-reviewed in February of 2009
for the U.S. EPA.240
CMAQ includes many science modules that simulate the emission, production, decay,
deposition and transport of organic and inorganic gas-phase and particle-phase pollutants in the
atmosphere. EPA intends to use the most recent version of CMAQ which reflects updates to
version 4.7 to improve the underlying science. These include aqueous chemistry mass
conservation improvements, improved vertical convective mixing and lowered CB05 mechanism
unit yields for acrolein from 1,3-butadiene tracer reactions which were updated to be consistent
with laboratory measurements.
The CMAQ modeling domain will encompass all of the lower 48 States and portions of
Canada and Mexico. The modeling domain will include a large continental U.S. 36 km grid and
two 12 km grids (an Eastern U.S. and a Western U.S. domain), as shown in Figure 8-4. The
modeling domain will contain 14 vertical layers with the top of the modeling domain at about
16,200 meters, or 100 millibars (mb).
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Figure 8-4 CMAQ 12-km Eastern and Western US Modeling Domains
The key inputs to the CMAQ model include emissions from anthropogenic and biogenic
sources, meteorological data, and initial and boundary conditions. The CMAQ meteorological
input files will be derived from simulations of the Pennsylvania State University /National
Center for Atmospheric Research Mesoscale Model241 for the entire year of 2005. This model,
commonly referred to as MM5, is a limited-area, nonhydrostatic, terrain-following system that
solves for the full set of physical and thermodynamic equations which govern atmospheric
motions.242 The meteorology for the national 36 km grid and the 12 km Eastern and Western
U.S. grids will be developed by EPA and described in more detail within the final RIA and the
technical support document for the final rulemaking air quality modeling.
The lateral boundary and initial species concentrations will be provided by a three-
dimensional global atmospheric chemistry model, the GEOS-CHEM model.243 The global
GEOS-CHEM model simulates atmospheric chemical and physical processes driven by
assimilated meteorological observations from the NASA's Goddard Earth Observing System
(GEOS). This model will be run for 2005 with a grid resolution of 2 degree x 2.5 degree
(latitude-longitude) and 20 vertical layers. The predictions will be used to provide one-way
dynamic boundary conditions at three-hour intervals and an initial concentration field for the 36
km CMAQ simulations. The future base conditions from the 36 km coarse grid modeling will be
used as the initial/boundary state for all subsequent 12 km finer grid modeling.
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8.3 Quantified and Monetized Non-GHG Health and Environmental
Impacts
This section discusses the non-GHG health and environmental impacts that can be
expected to occur as a result of the proposed heavy-duty vehicle GHG rule. GHG emissions are
predominantly the byproduct of fossil fuel combustion processes that also produce criteria and
hazardous air pollutants. The vehicles that are subject to the proposed standards are also
significant sources of mobile source air pollution such as direct PM, NOX, VOCs and air toxics.
The proposed standards would affect exhaust emissions of these pollutants from vehicles. They
would also affect emissions from upstream sources related to changes in fuel consumption.
Changes in ambient ozone, PM2.5, and air toxics that would result from the proposed standards
are expected to affect human health in the form of premature deaths and other serious human
health effects, as well as other important public health and welfare effects.
It is important to quantify the health and environmental impacts associated with the
proposed standard because a failure to adequately consider these ancillary co-pollutant impacts
could lead to an incorrect assessment of their net costs and benefits. Moreover, co-pollutant
impacts tend to accrue in the near term, while any effects from reduced climate change mostly
accrue over a time frame of several decades or longer.
EPA typically quantifies and monetizes the health and environmental impacts related to
both PM and ozone in its regulatory impact analyses (RIAs), when possible. However, EPA was
unable to do so in time for this proposal. EPA attempts to make emissions and air quality
modeling decisions early in the analytical process so that we can complete the photochemical air
quality modeling and use that data to inform the health and environmental impacts analysis.
Resource and time constraints precluded the Agency from completing this work in time for the
proposal. Instead, we provide a characterization of the health and environmental impacts that
will be quantified and monetized for the final rulemaking.
EPA bases its analyses on peer-reviewed studies of air quality and health and welfare
effects and peer-reviewed studies of the monetary values of public health and welfare
improvements, and is generally consistent with benefits analyses performed for the analysis of
the final Ozone National Ambient Air Quality Standard (NAAQS) and the final PM NAAQS
analysis, as well as the proposed Portland Cement National Emissions Standards for Hazardous
Air Pollutants (NESHAP) RIA, and final NO2 NAAQS.244'245' 246'247
8.3.1 Human Health and Environmental Impacts
To model the ozone and PM air quality benefits of the final rule, EPA will use the
Community Multiscale Air Quality (CMAQ) model (see Section 8.2.3 for a description of the
CMAQ model). The modeled ambient air quality data will serve as an input to the
Environmental Benefits Mapping and Analysis Program (BenMAP).248 BenMAP is a computer
program developed by EPA that integrates a number of the modeling elements used in previous
RIAs (e.g., interpolation functions, population projections, health impact functions, valuation
functions, analysis and pooling methods) to translate modeled air concentration estimates into
health effects incidence estimates and monetized benefits estimates.
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Table 8-2 lists the co-pollutant health effect exposure-response functions we will use to
quantify the co-pollutant incidence impacts associated with the final heavy-duty vehicles
standard.
(Table 8-2 starts on the following page)
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Table 8-2: Health Impact Functions Used in BenMAP to Estimate Impacts of PM25 and Ozone Reductions
ENDPOINT
POLLUTANT
STUDY
STUDY POPULATION
Premature Mortality
Premature mortality -
daily time series
Premature mortality
— cohort study, all-
cause
Premature mortality,
total exposures
Premature mortality
— all-cause
03
PM25
PM25
PM25
Multi-city
Bell et al (2004) (NMMAPS study)249 - Non-
accidental
Huang et al (2005)250 - Cardiopulmonary
Schwartz (2005)251 - Non-accidental
Meta-analyses:
Bell et al (2005)252 - All cause
Ito et al (2005)253 - Non-accidental
Levy et al (2005)254 - All cause
Pope etal. (2002) 255
Laden et al. (2006)256
Expert Elicitation (lEc, 2006) 257
Woodruff et al. ( 1997) 258
All ages
>29 years
>25 years
>24 years
Infant (<1 year)
Chronic Illness
Chronic bronchitis
Nonfatal heart attacks
PM25
PM25
Abbey etal. (1995)259
Peters etal. (200 1)260
>26 years
Adults (>18 years)
Hospital Admissions
Respiratory
Cardiovascular
03
PM25
PM25
PM25
PM25
PM25
PM25
Pooled estimate:
Schwartz (1995) - ICD 460-519 (all resp)261
Schwartz (1994a; 1994b) - ICD 480-486
(pneumonia)262'263
Moolgavkar et al. (1997) - ICD 480-487
(pneumonia)264
Schwartz (1994b) - ICD 491-492, 494-496
(COPD)
Moolgavkar et al. (1997) - ICD 490-496
(COPD)
Burnett etal. (200 1)265
Pooled estimate:
Moolgavkar (2003)— ICD 490-496 (COPD)266
Ito (2003)— ICD 490-496 (COPD)267
Moolgavkar (2000)— ICD 490-496 (COPD)268
Ito (2003)— ICD 480-486 (pneumonia)
Sheppard (2003)— ICD 493 (asthma)269
Pooled estimate:
Moolgavkar (2003)— ICD 390-429 (all
cardiovascular)
Ito (2003)— ICD 410-414, 427-428 (ischemic
heart disease, dysrhythmia, heart failure)
Moolgavkar (2000)— ICD 390-429 (all
cardiovascular)
>64 years
<2 years
>64 years
20-64 years
>64 years
<65 years
>64 years
20-64 years
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ENDPOINT
Asthma-related ER
visits
Asthma-related ER
visits (con't)
POLLUTANT
03
PM25
STUDY
Pooled estimate:
Peel etal (2005) 27°
Wilson et al (2005)271
Norrisetal. (1999)272
STUDY POPULATION
All ages
All ages
0-18 years
Other Health Endpoints
Acute bronchitis
Upper respiratory
symptoms
Lower respiratory
symptoms
Asthma exacerbations
Work loss days
School absence days
Minor Restricted
Activity Days
(MRADs)
PM25
PM25
PM25
PM25
PM25
03
03
PM25
Dockeryetal. (1996)273
Pope etal. (1991)274
Schwartz and Neas (2000)275
Pooled estimate:
Ostro et al. (200 1)276 (cough, wheeze and
shortness of breath)
Vedal et al. (1998)277 (cough)
Ostro (1987)278
Pooled estimate:
Gilliland et al. (2001)279
Chen etal. (2000)280
Ostro and Rothschild (1989)281
Ostro and Rothschild (1989)
8-12 years
Asthmatics, 9-11
years
7-14 years
6-18 years3
18-65 years
5-17 years'3
18-65 years
18-65 years
Notes:
a The original study populations were 8 to 13 for the Ostro et al. (2001) study and 6 to 13 for the Vedal et al. (1998)
study. Based on advice from the Science Advisory Board Health Effects Subcommittee (SAB-HES), we extended
the applied population to 6 to 18, reflecting the common biological basis for the effect in children in the broader age
group. See: U.S. Science Advisory Board. 2004. Advisory Plans for Health Effects Analysis in the Analytical Plan
for EPA's Second Prospective Analysis -Benefits and Costs of the Clean Air Act, 1990—2020. EPA-SAB-
COUNCIL-ADV-04-004. See also National Research Council (NRC). 2002. Estimating the Public Health Benefits
of Proposed Air Pollution Regulations. Washington, DC: The National Academies Press.
b Gilliland et al. (2001) studied children aged 9 and 10. Chen et al. (2000) studied children 6 to 11. Based on recent
advice from the National Research Council and the EPA SAB-HES, we have calculated reductions in school
absences for all school-aged children based on the biological similarity between children aged 5 to 17.
8.3.2 Monetized Impacts
Table 8-3presents the monetary values we will apply to changes in the incidence of health
and welfare effects associated with reductions in non-GHG pollutants that will occur when these
GHG control strategies are finalized.
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Table 8-3: Valuation Metrics Used in BenMAP to Estimate Monetary Co-Benefits
Endpoint
Valuation Method
Premature mortality
Assumed Mean VSL
Chronic Illness
Chronic Bronchitis
Myocardial Infarctions, Nonfatal
WTP: Average Severity
Medical Costs Over 5 Years. Varies by
age and discount rate. Russell
(1998)282
Medical Costs Over 5 Years. Varies by
age and discount rate. Wittels
(1990)283
Work Loss Days
Minor Restricted Activity Days
School Absence Days
Worker Productivity
Chestnut (1986) 286
Median Daily Wage, County-Specific
WTP: 1 Day, CV Studies
Median Daily Wage, Women 25+
Median Daily Wage, Outdoor
Workers, County-Specific
Environmental Endpoints
Recreational Visibility
WTP: 86 Class I Areas
Valuation
(2000$)
$6,300,000
$340,482
Hospital Admissions
Respiratory, Age 65+
Respiratory, Ages 0-2
Chronic Lung Disease (less
Asthma)
Pneumonia
Asthma
Cardiovascular
ER Visits, Asthma
Other Health Endpoints
Acute Bronchitis
Upper Respiratory Symptoms
Lower Respiratory Symptoms
Asthma Exacerbation
COI: Medical Costs + Wage Lost
COI: Medical Costs
COI: Medical Costs + Wage Lost
COI: Medical Costs + Wage Lost
COI: Medical Costs + Wage Lost
COI: Medical Costs + Wage Lost (20-
64)
COI: Medical Costs + Wage Lost (65-
99)
COI: Smith etal. (1997) 284
COI: Standford et al. (1999)285
WTP: 6 Day Illness, CV Studies
WTP: 1 Day, CV Studies
WTP: 1 Day, CV Studies
WTP: Bad Asthma Day, Rowe and
$18,353
$7,741
$12,378
$14,693
$6,634
$22,778
$21,191
$312
$261
$356
$25
$16
$43
$51
$75
Source: Dollar amounts for each valuation method were extracted from BenMAP version 3.0.
8.3.3 Other Unquantified Health and Environmental Impacts
In addition to the co-pollutant health and environmental impacts we will quantify for the
analysis of the heavy-duty vehicle GHG standard, there are a number of other health and human
welfare endpoints that we will not be able to quantify because of current limitations in the
methods or available data. These impacts are associated with emissions of air toxics (including
benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and acrolein), ambient ozone, and ambient
PM2.5 exposures. For example, we have not quantified a number of known or suspected health
effects linked with ozone and PM for which appropriate health impact functions are not available
or which do not provide easily interpretable outcomes (e.g., changes in heart rate variability). In
addition, we are currently unable to quantify a number of known welfare effects, including
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reduced acid and particulate deposition damage to cultural monuments and other materials, and
environmental benefits due to reductions of impacts of eutrophication in coastal areas. Table 8-4
lists these unquantified health and environmental impacts.
Table 8-4: Unquantified and Non-Monetized Potential Effects
POLLUTANT/EFFECTS
EFFECTS NOT INCLUDED IN ANALYSIS - CHANGES IN:
Ozone Health
Chronic respiratory damage
Premature aging of the lungs
Non-asthma respiratory emergency room visits
Exposure to UVb (+/-)d
Ozone Welfare
Yields for
-commercial forests
-some fruits and vegetables
-non-commercial crops
Damage to urban ornamental plants
Impacts on recreational demand from damaged forest aesthetics
Ecosystem functions
Exposure to UVb (+/-)
PM Health
Premature mortality - short term exposures
Low birth weight
Pulmonary function
Chronic respiratory diseases other than chronic bronchitis
Non-asthma respiratory emergency room visits
Exposure to UVb (+/-)
PM Welfare
Residential and recreational visibility in non-Class I areas
Soiling and materials damage
Damage to ecosystem functions
Exposure to UVb (+/-)
Nitrogen and Sulfate
Deposition Welfare
Commercial forests due to acidic sulfate and nitrate deposition
Commercial freshwater fishing due to acidic deposition
Recreation in terrestrial ecosystems due to acidic deposition
Existence values for currently healthy ecosystems
Commercial fishing, agriculture, and forests due to nitrogen deposition
Recreation in estuarine ecosystems due to nitrogen deposition
Ecosystem functions
Passive fertilization
CO Health
Behavioral effects
Hydrocaibon (HC)/Toxics
Health6
Cancer (benzene, 1,3-butadiene, formaldehyde, acetaldehyde)
Anemia (benzene)
Disruption of production of blood components (benzene)
Reduction in the number of blood platelets (benzene)
Excessive bone marrow formation (benzene)
Depression of lymphocyte counts (benzene)
Reproductive and developmental effects (1,3-butadiene)
Irritation of eyes and mucus membranes (formaldehyde)
Respiratory irritation (formaldehyde)
Asthma attacks in asthmatics (formaldehyde)
Asthma-like symptoms in non-asthmatics (formaldehyde)
Irritation of the eyes, skin, and respiratory tract (acetaldehyde)
Upper respiratory tract irritation and congestion (acrolein)
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HC/Toxics Welfaref
Direct toxic effects to animals
Bioaccumulation in the food chain
Damage to ecosystem function
Odor
Notes:
In addition to primary economic endpoints, there are a number of biological responses that have been associated
with ozone health effects including increased airway responsiveness to stimuli, inflammation in the lung, acute
inflammation and respiratory cell damage, and increased susceptibility to respiratory infection. The public health
impact of these biological responses may be partly represented by our quantified endpoints.
In addition to primary economic endpoints, there are a number of biological responses that have been associated
with PM health effects including morphological changes and altered host defense mechanisms. The public health
impact of these biological responses may be partly represented by our quantified endpoints.
0 While some of the effects of short-term exposures are likely to be captured in the estimates, there may be
premature mortality due to short-term exposure to PM not captured in the cohort studies used in this analysis.
However, the PM mortality results derived from the expert elicitation do take into account premature mortality
effects of short term exposures.
May result in benefits or disbenefits.
e Many of the key hydrocarbons related to this rule are also hazardous air pollutants listed in the Clean Air Act.
Please refer to Chapter 8.1.1 for additional information on the health effects of air toxics.
f Please refer to Chapter 8.1.2 for additional information on the welfare effects of air toxics.
While there will be impacts associated with air toxic pollutant emission changes that
result from the final standard, we will not attempt to monetize those impacts. This is primarily
because currently available tools and methods to assess air toxics risk from mobile sources at the
national scale are not adequate for extrapolation to incidence estimations or benefits assessment.
The best suite of tools and methods currently available for assessment at the national scale are
those used in the National-Scale Air Toxics Assessment (NAT A). The EPA Science Advisory
Board specifically commented in their review of the 1996 NATA that these tools were not yet
ready for use in a national-scale benefits analysis, because they did not consider the full
distribution of exposure and risk, or address sub-chronic health effects.287 While EPA has since
improved the tools, there remain critical limitations for estimating incidence and assessing
benefits of reducing mobile source air toxics. EPA continues to work to address these
limitations; however, we do not anticipate having methods and tools available for national-scale
^88
application in time for the analysis of the final rules.
8.4 Changes in Atmospheric CO2 Concentrations, Global Mean
Temperature, Sea Level Rise, and Ocean pH Associated with the
Proposal's GHG Emissions Reductions
8.4.1 Introduction
Based on modeling analysis performed by the EPA, reductions in CC>2 and other GHG
emissions associated with this proposal will affect climate change projections. Since GHGs are
well-mixed in the atmosphere and have long atmospheric lifetimes, changes in GHG emissions
will affect atmospheric concentrations of greenhouse gases and future climate for decades to
centuries and even millennia. This section provides estimates of the projected change in
atmospheric CC>2 concentrations based on the emission reductions estimated for this proposal
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(preferred approach). In addition, this section analyzes the following climate-related variables:
global mean temperature, sea level rise, and ocean pH. Provided here are projected estimates for
the response in atmospheric CC>2 concentrations, global mean temperature, sea level rise, and
ocean pH to the estimated net global GHG emissions reductions associated with the preferred
approach of this proposal (see Chapter 5 for the estimated net reductions in global emissions
over time by GHG).
8.4.2 Estimated Projected Change in Atmospheric CO2 Concentrations, Global
Mean Surface Temperatures and Sea Level Rise
To assess the impact of the emissions reductions from the proposed standards, EPA
estimated changes in projected atmospheric CC>2 concentrations, global mean surface
temperature and sea-level rise to 2100 using the GCAM (Global Change Assessment Model,
formerly MiniCAM), integrated assessment model0'289 coupled with the MAGICC (Model for
the Assessment of Greenhouse-gas Induced Climate Change) simple climate model.p'290'291
GCAM was used to create the globally and temporally consistent set of climate relevant
variables required for running MAGICC. MAGICC was then used to estimate the projected
change in these variables over time. Given the magnitude of the estimated emissions reductions
associated with the rule, a simple climate model such as MAGICC is reasonable for estimating
the atmospheric and climate response.
8.4.2.2 Methodology
An emissions scenario for the proposal was developed by applying the estimated
emissions reductions from the proposal's primary alternative to the GCAM reference (no climate
policy or baseline) scenario (used as the basis for the Representative Concentration Pathway
RCP4.5).292 Specifically, the annual CC>2, N2O, and CH4 emissions reductions from Chapter 5
were applied as net reductions to the GCAM global baseline net emissions for each GHG. All
emissions reductions were assumed to begin in 2014, with zero emissions change in 2013 and
linearly increasing to equal the value supplied (in Chapter 5) for 2018, 2030, and 2050 (CO,
GCAM is a long-term, global integrated assessment model of energy, economy, agriculture and land use that
considers the sources of emissions of a suite of greenhouse gases (GHG's), emitted in 14 globally disaggregated
regions, the fate of emissions to the atmosphere, and the consequences of changing concentrations of greenhouse
related gases for climate change. GCAM begins with a representation of demographic and economic developments
in each region and combines these with assumptions about technology development to describe an internally
consistent representation of energy, agriculture, land-use, and economic developments that in turn shape global
emissions.
p MAGICC consists of a suite of coupled gas-cycle, climate and ice-melt models integrated into a single framework.
The framework allows the user to determine changes in greenhouse-gas concentrations, global-mean surface air
temperature and sea-level resulting from anthropogenic emissions of carbon dioxide (CO2), methane (CH4), nitrous
oxide (N2O), reactive gases (CO, NOx, VOCs), the halocarbons (e.g. HCFCs, HFCs, PFCs) and sulfur dioxide
(SO2). MAGICC emulates the global-mean temperature responses of more sophisticated coupled
Atmosphere/Ocean General Circulation Models (AOGCMs) with high accuracy.
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SO2, VOCs, and NOx emissions reductions were only provided for these years). EPA linearly
scaled emissions reductions between the 0 input value in 2013 and the value supplied for 2018 to
produce the reductions between 2014 and 2018. A similar scaling was used for 2019-2029 and
2031-2050. The emissions reductions past 2050 were scaled with total U.S. road transportation
fuel consumption from the GCAM reference scenario. This was chosen as a simple scale factor
given that both direct and upstream emissions changes are included in the emissions reduction
scenario provided. Road transport fuel consumption past 2050 does not change significantly and
thus emissions reductions remain relatively constant from 2050 through 2100.
OQQ
The GCAM reference scenario depicts a world in which global population reaches a
maximum of more than 9 billion in 2065 and then declines to 8.7 billion in 2100 while global
GDP grows by an order of magnitude and global energy consumption triples. The reference
scenario includes no explicit policies to limit carbon emissions, and therefore fossil fuels
continue to dominate global energy consumption, despite substantial growth in nuclear and
renewable energy. Atmospheric CO2 concentrations rise throughout the century and reach 792
ppmv by 2100, with total radiative forcing approaching 7 Watts per square meter (W/m2) Forest
land declines in the reference scenario to accommodate increases in land use for food and
bioenergy crops. Even with the assumed agricultural productivity increases, the amount of land
devoted to crops increases in the first half of the century due to increases in population and
income (higher income drives increases in land-intensive meat consumption). After 2050 the
rate of growth in food demand slows, in part due to declining population. As a result the amount
of cropland and also land use change (LUC) emissions decline as agricultural crop productivity
continues to increase.
The GCAM reference scenario uses non-CO2 and pollutant emissions implemented as
described in Smith and Wigley (2006); land-use change emissions as described in Wise et al.
(2009); and updated base-year estimates of global GHG emissions. This scenario was created as
part of the Climate Change Science Program (CCSP) effort to develop a set of long-term global
emissions scenarios that incorporate an update of economic and technology data and utilize
improved scenario development tools compared to the IPCC Special Report on Emissions
Scenarios (SRES) (IPCC 2000).
Using MAGICC 5.3 v2,294 the change in atmospheric CC>2 concentrations, global mean
temperature, and sea level were projected at five-year time steps to 2100 for both the reference
(no climate policy) scenario and the emissions reduction scenario specific to the preferred
approach of this proposal. To capture some of the uncertainty in the climate system, the changes
in projected atmospheric CC>2 concentrations, global mean temperature and sea level were
estimated across the most current Intergovernmental Panel on Climate Change (IPCC) range of
climate sensitivities, 1.5°C to 6.0°C.Q The range as illustrated in Chapter 10, Box 10.2, Figure 2
In IPCC reports, equilibrium climate sensitivity refers to the equilibrium change in the annual mean
global surface temperature following a doubling of the atmospheric equivalent carbon dioxide
concentration. The IPCC states that climate sensitivity is "likely" to be in the range of 2°C to 4.5°C, "very
unlikely" to be less than 1.5°C, and "values substantially higher than 4.5°C cannot be excluded." IPCC
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of the IPCC's Working Group I is approximately consistent with the 10-90% probability
distribution of the individual cumulative distributions of climate sensitivity.29
The integrated impact of the following pollutant and greenhouse gas emissions changes
are considered: CO2, CH4, N2O, VOC, NOx, CO, and SO2. For CO, SO2, andNOx, emissions
reductions were estimated for 2018, 2030, and 2050. For CO2, CH/j, and N2O an annual time-
series of (upstream + downstream) emissions reductions estimated from the proposal were input
directly. The GHG emissions reductions, from Chapter 5, were applied as net reductions to a
global reference case (or baseline) emissions scenario in GCAM to generate an emissions
scenario specific to this proposal. EPA linearly scaled emissions reductions between a zero input
value in 2013 and the value supplied for 2018 to produce the reductions for 2014-2018. A
similar scaling was used for 2019-2029 and 2031-2050. The emissions reductions past 2050
were scaled with total U.S. road transportation fuel consumption from the GCAM reference
scenario. Road transport fuel consumption past 2050 does not change significantly and thus
emissions reductions remain relatively constant from 2050 through 2100. Specific details about
the reference case scenario and how the emissions reductions were applied to generate the
scenario can be found in the proposal's RIA, Chapter 8.4.
MAGICC is a global model and is primarily concerned with climate, therefore the impact
of short-lived climate forcing agents (e.g., Os) are not explicitly simulated as in regional air
quality models. While many precursors to short-lived climate forcers such as ozone are
considered, MAGICC simulates the longer term effect on climate from long-lived GHGs. The
impacts to ground-level ozone and other non-GHGs are discussed in Section VII of this proposal
and the draft RIA, Chapter 8.2. Some aerosols, such as black carbon, cause a positive forcing or
warming effect by absorbing incoming solar radiation. There remain some significant scientific
uncertainties about black carbon's total climate effect,R as well as concerns about how to treat
the short-lived black carbon emissions alongside the long-lived, well-mixed greenhouse gases in
a common framework (e.g., what are the appropriate metrics to compare the warming and/or
climate effects of the different substances, given that, unlike greenhouse gases, the magnitude of
aerosol effects can vary immensely with location and season of emissions). Further, estimates of
the direct radiative forcing of individual species are less certain than the total direct aerosol
radiative forcing.
There is no single accepted methodology for transforming black carbon emissions into
temperature change or CO2-equivalent emissions. The interaction of black carbon (and other co-
emitted aerosol species) with clouds is especially poorly quantified, and this factor is key to any
WGI, 2007, Climate Change 2007 - The Physical Science Basis, Contribution of Working Group I to the
Fourth Assessment Report of the IPCC, http://www.ipcc.ch/.
o
The range of uncertainty in the current magnitude of black carbon's climate forcing effect is evidenced by the
ranges presented by the IPCC Fourth Assessment Report (2007) and the more recent study by Ramanathan, V. and
Carmichael, G. (2008) Global and regional climate changes due to black carbon. Nature Geoscience, 1(4): 221-227.
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attempt to estimate the net climate impacts of black carbon. While black carbon is likely to be
an important contributor to climate change, it would be premature to include quantification of
black carbon climate impacts in an analysis of the proposed standards at this time.
To compute the reductions in atmospheric CC>2 concentration, global mean temperature,
and sea level rise specifically attributable to the impacts of the proposed standards, the output
from the proposal's primary emissions scenario was subtracted from the reference case (base
case) emissions scenario. As a result of the proposal's specified emissions reductions from the
primary alternative, the concentration of atmospheric CO 2 is projected to be reduced by
approximately 0.693 to 0.784 parts per million by volume (ppmv), the global mean temperature
is projected to be reduced by approximately 0.002-0.004°C by 2100 and global mean sea level
rise is projected to be reduced by approximately 0.012-0.48 cm by 2100. The reference (no
policy) and the specified emission reductions scenarios were subtracted from global emissions
for the years 2000-2100. The difference between these two results is the impact of the preferred
approach of this proposal on global CC>2 concentrations and other key climate variables.
Figure 8-5 provides the results over time for the estimated reductions in atmospheric CC>2
concentration associated with the proposal. Figure 8-6 provides the estimated change in
projected global mean temperatures associated with the proposal. Figure 8-7 provides the
estimated reductions in global mean sea level rise associated with the proposal. The range of
reductions in global mean temperature and sea level rise is larger because CO2 concentrations
are not tightly coupled to climate sensitivity, whereas the magnitude of temperature change
response to CO2 changes (and therefore sea level rise) is tightly coupled to climate sensitivity in
the MAGICC model.
Change in CO2 Concentration
(Primary Alternative - Reference)
m m K-
2000
2020 2040
2060
2080
2100
Figure 8-5 Estimated Projected Reductions in Atmospheric CO2 Concentrations (parts per million by
volume) from Baseline for the Proposed Heavy-Duty Rule (climate sensitivity (CS) cases ranging from 1.5-
6°C)
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Environmental and Health
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0.000
-0.005
Change in Global Mean Temperature
(Primary Alternative - Reference)
2000
2020
2040
2060
2080
2100
Figure 8-6 Estimated Projected Reductions in Global Mean Surface Temperatures from Baseline for the
Proposed Heavy-Duty Rule (climate sensitivity (CS) cases ranging from 1.5-6°C)
-0.06
Change in Global Mean Sea Level Rise
(Primary Alternative - Reference)
2000
2020
2040
2060
2080
2100
Figure 8-7 Estimated Projected Reductions in Global Mean Sea Level Rise from Baseline for the Final
Proposed Heavy-Duty Rule (climate sensitivity (CS) cases ranging from 1.5-6°C)
The results in Figure 8-6 and Figure 8-7 show a relatively small reduction in the
projected global mean temperature and sea level respectively, across all climate sensitivities. The
projected reductions are small relative to the IPCC's 2100 "best estimates" for global mean
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Draft Regulatory Impact Analysis
temperature increases (1.1 - 6.4°C) and sea level rise (0.18-0.59 cm) for all global GHG
emissions sources for a range of emissions scenarios.8'296 However, this is to be expected given
the magnitude of reductions from the proposal in the context of global emissions.
8.4.3 Estimated Projected Change in Ocean pH
For this proposal, EPA analyzes another key climate-related variable and calculates
projected change in ocean pH for tropical waters. For this analysis, changes in ocean pH are
related to the change in the atmospheric concentration of carbon dioxide (CO2) resulting from
the preferred approach of this proposal. EPA used the program developed for CC>2 System
Calculations (CO2SYS) CO2SYS,297 version 1.05, a program which performs calculations
relating parameters of the carbon dioxide (CO2) system in seawater. The program was
developed by Ernie Lewis at Brookhaven National Laboratory and Doug Wallace at the Insitut
fuer Meereskunde in Germany, supported by the U.S. Department of Energy, Office of
Biological and Environmental Research, under Contract No. DE-ACO2-76CH00016.
The program uses two of the four measurable parameters of the CO2 system [total
alkalinity (TA), total inorganic CC>2 (TC), pH, and either fugacity (fCC^) or partial pressure of
CO2 (pCCh)] to calculate the other two parameters given a specific set of input conditions
(temperature and pressure) and output conditions chosen by the user. EPA utilized the DOS
9QR
version (Lewis and Wallace, 1998) of the program to compute pH under two emissions
scenarios as follows:
1) A reference case scenario which was based on the change in atmospheric CO2
concentrations (also known as partial pressure) in 2100 in parts per million by volume
(ppmv) from reference scenario developed for the MAGICC modeling [modeling was
performed across a range of climate sensitivities 1.5-6.0°C].
2) An emissions reduction scenario based on the proposal's preferred alternative which
reduces atmospheric CO2 concentrations in 2100 by 0.693 to 0.784 ppmv [MAGICC
modeling was performed across a range of climate sensitivities 1.5-6.0°C].
In order to determine the change in pH resulting from the emissions reduction, EPA
subtracted the reference scenario pH from the emission reduction scenario pH for each climate
sensitivity case. The analysis indicates that the emissions reductions in 2100 result in a slight
increase in ocean pH of 0.0003 by the year 2100. The values for pH under the two scenarios
varied according to the climate sensitivity being evaluated. Using the set of seawater parameters
detailed below and the climate sensitivity case of 3.0, the reference scenario pH was 7.7888 and
the emissions reduction scenario was 7.7891 resulting in a difference of 0.0003.
The CO2SYS program required the input of a number of variables and constants for each
scenario for calculated the result for both the reference case and the proposal's emissions
s IPCC WGI, 2007. The IPCC "best estimates" include only emissions uncertainty, and not any climate parameter
uncertainty. The sea level rise estimates exclude any possible future dynamical changes in ice flow from ice sheets.
The baseline temperature increases by 2100 from our MiniCAM-MAGICC runs are 1.8°C to 4.5°C.
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reduction case. EPA used the following inputs, with justification and references for these inputs
provided in brackets:
1) Input mode: Single-input [This simply means that the program calculates pH for one set
of input variables at a time, instead of a batch of variables. The choice has no affect on
results].
2) Choice of constants: Mehrbach et al. (1973)299, refit by Dickson and Millero (1987)300
3) Choice of fCC>2 or pCC^: pCC>2 [pCC>2 is the partial pressure of CO2 and can be
converted to fugacity (fCO2) if desired]
4) Choice of KSO4: Dickson (1990)301 [Lewis and Wallace (1998)302 recommend using the
equation of Dickson (1990) for this dissociation constant. The model also allows the use
of the equation of Khoo et al. (1977).303 Switching this parameter to Khoo et al. (1977)
instead of Dickson (1990) had no effect on the calculated result].
5) Choice of pH scale: Total scale [The model allows pH outputs to be provided on the total
scale, the seawater scale, the free scale, and the National Bureau of Standards (NBS)
scale. The various pH scales can be interrelated using equations provided by Lewis and
Wallace (1998)].
The program provides several choices of constants for saltwater that are needed for the
calculations. EPA calculated pH values using all choices and found that in all cases the choice
had an indistinguishable effect on the results. Additional inputs are required and EPA ran the
model using a variety of input values to test whether the model was sensitive to these inputs.
EPA found the model was not sensitive to these inputs in terms of the incremental change in pH
calculated for each climate sensitivity case. The input values are derived from certified reference
materials of sterilized natural sea water (Dickson, 2003, 2005, and 2009).304 Based on the
projected atmospheric CC>2 concentration reductions that would result from this proposal (0.731
ppmv for a climate sensitivity of 3.0), the modeling program calculates an increase in ocean pH
of approximately 0.0003 pH units in 2100. Thus, this analysis indicates the projected decrease in
atmospheric CC>2 concentrations from the preferred approach of this proposal yields an increase
in ocean pH. Table 8-5 contains the projected change results in ocean pH based the change in
atmospheric CC>2 concentrations.
Table 8-5: Impact of Proposal's GHG Emissions Reductions On Ocean pH
CLIMATE
SENSITIVITY
3.0
DIFFERENCE
INCO2a
-0.731
YEAR
2100
PROJECTED
CHANGE
0.0003
a represents the change in atmospheric CO2 concentrations in 2100 based on the difference from the
proposal's preferred alternative from the GCAM reference scenario used in the MAGICC modeling.
8.4.4 Summary of Climate Analyses
EPA's analysis of the impact of the proposal's preferred approach on global climate
conditions is intended to quantify these potential reductions using the best available science.
While EPA's modeling results of the impact of the preferred approach alone show small
differences in climate effects (CC>2 concentration, global mean temperature, sea level rise, and
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Draft Regulatory Impact Analysis
ocean pH), when expressed in terms of global climate endpoints and global GHG emissions, they
yield results that are repeatable and consistent within the modeling frameworks used. The results
are summarized in Table 8-6, Impact of GHG Emissions Reductions On Projected Changes in
Global Climate Associated with the Proposal.
These projected reductions are proportionally representative of changes to U.S. GHG
emissions in the transportation sector. While not formally estimated for this proposal, a reduction
in projected global mean temperature and sea level rise implies a reduction in the risks associated
with climate change. The figures for these variables illustrate that the distribution across a range
of climate sensitivities for projected global mean temperature and sea level rise shifts down. The
benefits of GHG emissions reductions can be characterized both qualitatively and quantitatively,
some of which can be monetized (see Chapter 8.5). There are substantial uncertainties in
modeling the global risks of climate change, which complicates quantification and cost-benefits
assessments. Changes in climate variables are a meaningful proxy for changes in the risk of all
potential impacts—including those that can be monetized, and those that have not been monetized
but can be quantified in physical terms (e.g., water availability), as well as those that have not yet
been quantified or are extremely difficult to quantify (e.g., forest disturbance and catastrophic
events such as collapse of large ice sheets and subsequent sea level rise).
Table 8-6 Impact of GHG Emissions Reductions On Projected Changes in Global Climate Associated with the
Proposal (based on a range of climate sensitivities from 1.5-6°C)
VARIABLE
Atmospheric COi
Concentration
Global Mean Surface
Temperature
Sea Level Rise
Ocean pH
UNITS
ppmv
°C
cm
pH units
YEAR
2100
2100
2100
2100
PROJECTED
CHANGE
-0.693 to -0.784
-0.002 to -0.004
-0.012 to -0.048
0.00036
The value for projected change in ocean pH is based on a climate sensitivity of 3.0.
8.5 Monetized CO2 Impacts
We assigned a dollar value to reductions in carbon dioxide (CO2) emissions using recent
estimates of the "social cost of carbon" (SCC). The SCC is an estimate of the monetized
damages associated with an incremental increase in carbon emissions in a given year. It is
intended to include (but is not limited to) changes in net agricultural productivity, human health,
property damages from increased flood risk, and the value of ecosystem services due to climate
change. The SCC estimates used in this analysis were developed through an interagency process
that included EPA, DOT/NHTSA, and other executive branch entities, and concluded in
February 2010. We first used these SCC estimates in the benefits analysis for the final joint
EPA/DOT Rulemaking to establish Light-Duty Vehicle Greenhouse Gas Emission Standards and
Corporate Average Fuel Economy Standards; see the rule's preamble for discussion about
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application of the SCC (75 FR 25324; 5/7/10). The SCC Technical Support Document (SCC
TSD) provides a complete discussion of the methods used to develop these SCC estimates.1
The interagency group selected four SCC values for use in regulatory analyses, which we
have applied in this analysis: $5, $22, $36, and $66 per metric ton of CC>2 emissions in 2010, in
2008 dollars.11'v The first three values are based on the average SCC from three integrated
assessment models, at discount rates of 5, 3, and 2.5 percent, respectively. SCCs at several
discount rates are included because the literature shows that the SCC is quite sensitive to
assumptions about the discount rate, and because no consensus exists on the appropriate rate to
use in an intergenerational context. The fourth value is the 95th percentile of the SCC from all
three models at a 3 percent discount rate. It is included to represent higher-than-expected
impacts from temperature change further out in the tails of the SCC distribution. Low
probability, high impact events are incorporated into all of the SCC values through explicit
consideration of their effects in two of the three models as well as the use of a probability density
function for equilibrium climate sensitivity. Treating climate sensitivity probabilistically results
in more high temperature outcomes, which in turn lead to higher projections of damages.
The SCC increases over time because future emissions are expected to produce larger
incremental damages as physical and economic systems become more stressed in response to
greater climatic change. Note that the interagency group estimated the growth rate of the SCC
directly using the three integrated assessment models rather than assuming a constant annual
growth rate. This helps to ensure that the estimates are internally consistent with other modeling
assumptions. Table VIII.G.1-1 presents the SCC estimates used in this analysis.
When attempting to assess the incremental economic impacts of carbon dioxide
emissions, the analyst faces a number of serious challenges. A recent report from the National
Academies of Science (NRC 2009) points out that any assessment will suffer from uncertainty,
speculation, and lack of information about (1) future emissions of greenhouse gases, (2) the
effects of past and future emissions on the climate system, (3) the impact of changes in climate
T Docket ID EPA-HQ-OAR-2009-0472-114577, Technical Support Document: Social Cost of Carbon for
Regulatory Impact Analysis Under Executive Order 12866, Interagency Working Group on Social Cost of Carbon,
with participation by Council of Economic Advisers, Council on Environmental Quality, Department of Agriculture,
Department of Commerce, Department of Energy, Department of Transportation, Environmental Protection Agency,
National Economic Council, Office of Energy and Climate Change, Office of Management and Budget, Office of
Science and Technology Policy, and Department of Treasury (February 2010). Also available at
http://epa.gov/otaq/climate/regulations.htm
u The interagency group decided that these estimates apply only to CO2 emissions. Given that warming profiles and
impacts other than temperature change (e.g. ocean acidification) vary across GHGs, the group concluded
"transforming gases into CO2-equivalents using GWP, and then multiplying the carbon-equivalents by the SCC,
would not result in accurate estimates of the social costs of non-CO2 gases" (SCC TSD, pg 13).
v The SCC estimates were converted from 2007 dollars to 2008 dollars using a GDP price deflator (1.021) obtained
from the Bureau of Economic Analysis, National Income and Product Accounts Table 1.1.4, Prices Indexes for
Gross Domestic Product.
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Draft Regulatory Impact Analysis
on the physical and biological environment, and (4) the translation of these environmental
impacts into economic damages.305 As a result, any effort to quantify and monetize the harms
associated with climate change will raise serious questions of science, economics, and ethics and
should be viewed as provisional.
The interagency group noted a number of limitations to the SCC analysis, including the
incomplete way in which the integrated assessment models capture catastrophic and non-
catastrophic impacts, their incomplete treatment of adaptation and technological change,
uncertainty in the extrapolation of damages to high temperatures, and assumptions regarding risk
aversion. The limited amount of research linking climate impacts to economic damages makes
the interagency modeling exercise even more difficult. The interagency group hopes that over
time researchers and modelers will work to fill these gaps and that the SCC estimates used for
regulatory analysis by the Federal government will continue to evolve with improvements in
modeling. Additional details on these limitations are discussed in the SCC TSD.
In light of these limitations, the interagency group has committed to updating the current
estimates as the science and economic understanding of climate change and its impacts on
society improves over time. Specifically, the interagency group has set a preliminary goal of
revisiting the SCC values in the next few years or at such time as substantially updated models
become available, and to continue to support research in this area.
Applying the global SCC estimates, shown in Table 8-7, to the estimated reductions in
domestic CC>2 emissions for the proposed rule, we estimate the dollar value of the climate related
benefits for each analysis year. For internal consistency, the annual benefits are discounted back
to net present value terms using the same discount rate as each SCC estimate (i.e. 5%, 3%, and
2.5%) rather than 3% and 7%.w The SCC estimates are presented in and the associated CO2
benefit estimates for each calendar year are shown in Table 8-8.
w It is possible that other benefits or costs of proposed regulations unrelated to CO2 emissions will be discounted at
rates that differ from those used to develop the SCC estimates.
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Table 8-7 Social Cost of CO2,2010 - 2050a (in 2008 dollars)
Year
2010
2015
2020
2025
2030
2035
2040
2045
2050
Discount Rate and Statistic
5% Average
$4.80
$5.87
$6.94
$8.45
$9.95
$11.46
$12.97
$14.50
$16.03
3% Average
$21.85
$24.35
$26.85
$30.15
$33.44
$36.73
$40.02
$42.93
$45.84
2.5% Average
$35.84
$39.21
$42.58
$46.84
$51.10
$55.36
$59.63
$63.00
$66.37
3%
95th percentile
$66.26
$74.33
$82.39
$92.25
$102.10
$111.95
$121.81
$130.43
$139.06
a The SCC values are dollar-year and emissions-year specific.
Table 8-8 Upstream and Downstream CO2 Benefits for the Given SCC Value, Calendar Year Analysis"
(Millions of 2008 dollars)
YEAR
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
5%
(AVERAGE SCC =
$5 IN 20 10)
$0
$0
$23
$47
$74
$112
$154
$195
$237
$280
$324
$368
$414
$460
$506
$552
$598
$643
$689
$733
$776
$821
$866
$912
$959
$1,006
$1,054
$1,103
$1,153
$1,203
3%
(AVERAGE SCC =
$22 IN 20 10)
$0
$0
$97
$196
$301
$452
$612
$766
$916
$1,064
$1,208
$1,352
$1,497
$1,641
$1,782
$1,919
$2,052
$2,183
$2,313
$2,436
$2,556
$2,677
$2,798
$2,922
$3,047
$3,173
$3,301
$3,429
$3,559
$3,682
2.5%
(AVERAGE SCC =
$36 IN 20 10)
$0
$0
$156
$315
$483
$722
$976
$1,217
$1,452
$1,680
$1,899
$2,117
$2,335
$2,550
$2,759
$2,961
$3,156
$3,346
$3,535
$3,712
$3,883
$4,056
$4,229
$4,405
$4,582
$4,760
$4,939
$5,120
$5,302
$5,467
3%
(95™ PERCENTILE =
$66 IN 20 10)
$0
$0
$294
$597
$919
$1,381
$1,875
$2,347
$2,810
$3,264
$3,703
$4,143
$4,584
$5,022
$5,451
$5,868
$6,272
$6,668
$7,063
$7,435
$7,798
$8,165
$8,532
$8,908
$9,286
$9,666
$10,051
$10,440
$10,832
$11,201
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Draft Regulatory Impact Analysis
2042
2043
2044
2045
2046
2047
2048
2049
2050
NPVb
$1,255
$1,307
$1,361
$1,416
$1,472
$1,529
$1,588
$1,648
$1,709
$8,605
$3,806
$3,933
$4,063
$4,193
$4,327
$4,463
$4,602
$4,743
$4,888
$43,991
$5,635
$5,805
$5,979
$6,153
$6,331
$6,513
$6,697
$6,884
$7,076
$74,572
$11,575
$11,957
$12,347
$12,740
$13,141
$13,551
$13,968
$14,392
$14,826
$134,077
"The SCC values are dollar-year and emissions-year specific.
b Note that net present value of reduced GHG emissions is calculated differently than other benefits.
discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 2.5 percent)
calculate net present value of SCC for internal consistency. Refer to SCC TSD for more detail.
The same
is used to
We also conducted a separate analysis of the CC>2 benefits over the model year lifetimes
of the 2014 through 2018 model year vehicles. In contrast to the calendar year analysis, the
model year lifetime analysis shows the lifetime impacts of the program on each of these MY
fleets over the course of its lifetime. Full details of the inputs to this analysis can be found in
RIA chapter 5. The CC>2 benefits of the full life of each of the five model years from 2014
through 2018 are shown in Table 8-9 through Table 8-12 for each of the four different social cost
of carbon values. The CC>2 benefits are shown for each year in the model year life and in net
present value. The same discount rate used to discount the value of damages from future
emissions (SCC at 5, 3, 2.5 percent) is used to calculate net present value of SCC for internal
consistency.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Environmental and Health
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Table 8-9 Upstream and Downstream CO2 Benefits for the 5% (Average SCC) Value, Model Year Analysis"
(Millions of 2008 dollars)
YEAR
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
NPV,
5%
MY 2014
$0
$0
$18
$17
$16
$16
$15
$14
$13
$12
$11
$10
$9
$8
$7
$7
$6
$5
$5
$4
$4
$3
$3
$2
$2
$2
$1
$1
$1
$1
$1
$1
$1
$0
$0
$0
$0
$0
$0
$200
MY 2015
$0
$0
$0
$19
$19
$18
$17
$16
$15
$14
$13
$12
$11
$10
$9
$8
$7
$6
$6
$5
$4
$4
$3
$3
$2
$2
$2
$2
$1
$1
$1
$1
$1
$1
$0
$0
$0
$0
$0
$200
MY 2016
$0
$0
$0
$0
$22
$21
$20
$19
$18
$17
$16
$15
$14
$13
$11
$10
$9
$8
$7
$7
$6
$5
$4
$4
$3
$3
$2
$2
$2
$2
$1
$1
$1
$1
$1
$0
$0
$0
$0
$200
MY 2017
$0
$0
$0
$0
$0
$35
$33
$32
$30
$29
$27
$25
$23
$21
$19
$18
$16
$14
$13
$11
$10
$9
$8
$7
$6
$5
$4
$4
$3
$3
$2
$2
$2
$2
$1
$2
$0
$0
$0
$300
MY 2018
$0
$0
$0
$0
$0
$0
$40
$38
$36
$35
$33
$31
$29
$27
$25
$23
$20
$19
$17
$15
$13
$12
$10
$9
$8
$7
$6
$5
$5
$4
$3
$3
$3
$2
$2
$2
$2
$0
$0
$300
SUM
$0
$0
$18
$37
$57
$90
$125
$119
$112
$106
$99
$92
$85
$78
$72
$65
$59
$53
$47
$42
$37
$33
$29
$25
$22
$19
$16
$14
$12
$10
$9
$8
$7
$5
$4
$3
$2
$0
$0
$1,100
"The SCC values are dollar-year and emissions-year specific.
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Table 8-10 Upstream and Downstream CO2 Benefits for the 3% (Average SCC) SCC Value, Model Year
Analysis3 (Millions of 2008 dollars)
YEAR
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
NPV,
3%
MY 2014
$0
$0
$75
$71
$67
$63
$59
$54
$50
$45
$41
$37
$33
$30
$26
$23
$20
$18
$16
$13
$12
$10
$8
$7
$6
$5
$4
$4
$3
$3
$2
$2
$2
$0
$0
$0
$0
$0
$0
$600
MY 2015
$0
$0
$0
$81
$76
$72
$68
$63
$58
$53
$48
$43
$39
$35
$32
$28
$25
$22
$19
$16
$14
$12
$11
$9
$8
$7
$6
$5
$4
$3
$3
$2
$2
$2
$0
$0
$0
$0
$0
$600
MY 2016
$0
$0
$0
$0
$91
$86
$81
$76
$71
$65
$60
$54
$49
$45
$40
$36
$32
$28
$25
$22
$19
$17
$14
$12
$11
$9
$8
$7
$6
$5
$4
$3
$3
$2
$3
$0
$0
$0
$0
$700
MY 2017
$0
$0
$0
$0
$0
$140
$132
$125
$117
$108
$99
$91
$83
$76
$69
$61
$55
$49
$43
$38
$33
$29
$25
$22
$19
$16
$14
$12
$10
$9
$7
$6
$5
$5
$4
$5
$0
$0
$0
$1,000
MY 2018
$0
$0
$0
$0
$0
$0
$157
$148
$140
$131
$122
$112
$104
$95
$86
$78
$70
$63
$56
$50
$44
$39
$34
$29
$26
$22
$19
$16
$14
$12
$10
$9
$7
$6
$5
$5
$6
$0
$0
$1,200
SUM
$0
$0
$75
$152
$234
$361
$497
$466
$435
$403
$369
$338
$308
$280
$253
$227
$202
$180
$159
$140
$122
$107
$92
$80
$69
$59
$51
$43
$37
$32
$27
$23
$20
$16
$12
$9
$6
$0
$0
$4,200
aThe SCC values are dollar-year and emissions-year specific.
8-58
-------
Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Environmental and Health
Impacts
Table 8-11 Upstream and Downstream CO2 Benefits for the from 2.5% (Average SCC) SCC Value,
Model Year Analysis3 (Millions of 2008 dollars)
YEAR
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
NPV,
2.5%
MY 2014
$0
$0
$121
$115
$108
$101
$94
$86
$79
$71
$64
$58
$51
$46
$41
$36
$31
$27
$24
$21
$18
$15
$13
$11
$9
$8
$7
$6
$5
$4
$3
$3
$3
$0
$0
$0
$0
$0
$0
$1,000
MY 2015
$0
$0
$0
$130
$122
$115
$108
$100
$92
$83
$75
$68
$61
$55
$49
$43
$38
$33
$29
$25
$22
$19
$16
$14
$12
$10
$8
$7
$6
$5
$4
$4
$3
$o
3
$0
$0
$0
$0
$0
$1,000
MY 2016
$0
$0
$0
$0
$146
$137
$129
$121
$112
$103
$94
$85
$77
$70
$62
$56
$49
$43
$38
$33
$29
$25
$22
$19
$16
$14
$12
$10
$8
$7
$6
$5
$4
$4
$4
$0
$0
$0
$0
$1,100
MY 2017
$0
$0
$0
$0
$0
$224
$211
$198
$185
$171
$156
$143
$129
$117
$106
$95
$85
$75
$66
$58
$51
$44
$38
$33
$28
$24
$21
$18
$15
$13
$11
$9
$8
$7
$6
$7
$0
$0
$0
$1,600
MY 2018
$0
$0
$0
$0
$0
$0
$250
$236
$221
$207
$192
$176
$162
$147
$134
$121
$108
$97
$86
$76
$67
$58
$51
$44
$38
$33
$28
$24
$21
$18
$15
$13
$11
$9
$8
$7
$8
$0
$0
$1,800
SUM
$0
$0
$121
$245
$376
$577
$792
$741
$689
$635
$581
$529
$481
$435
$392
$350
$311
$275
$243
$213
$186
$161
$140
$121
$104
$89
$76
$65
$55
$47
$40
$34
$29
$23
$18
$14
$8
$0
$0
$6,500
aThe SCC values are dollar-year and emissions-year specific.
8-59
-------
Draft Regulatory Impact Analysis
Table 8-12 Upstream and Downstream CO2 Benefits for the 3% (95th Percentile) SCC Value, Model Year
Analysis3 (Millions of 2008 dollars)
YEAR
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
NPV,
3%
MY 2014
$0
$0
$229
$217
$205
$193
$180
$166
$152
$138
$125
$113
$101
$91
$80
$71
$62
$55
$47
$41
$35
$30
$26
$22
$19
$16
$14
$11
$10
$8
$7
$6
$7
$0
$0
$0
$0
$0
$0
$1,900
MY 2015
$0
$0
$0
$247
$233
$220
$207
$193
$177
$162
$146
$133
$120
$108
$96
$85
$75
$66
$58
$50
$44
$38
$32
$28
$24
$20
$17
$14
$12
$10
$9
$7
$6
$7
$0
$0
$0
$0
$0
$2,000
MY 2016
$0
$0
$0
$0
$277
$262
$248
$234
$217
$200
$183
$166
$151
$137
$123
$110
$98
$87
$76
$67
$58
$51
$44
$38
$32
$28
$24
$20
$17
$15
$12
$11
$9
$8
$9
$0
$0
$0
$0
$2,200
MY 2017
$0
$0
$0
$0
$0
$429
$405
$382
$358
$332
$305
$279
$254
$231
$210
$188
$168
$149
$132
$116
$102
$89
$77
$67
$57
$49
$43
$36
$31
$27
$22
$19
$16
$14
$12
$14
$0
$0
$0
$3,200
MY 2018
$0
$0
$0
$0
$0
$0
$481
$455
$428
$402
$374
$345
$318
$290
$264
$240
$215
$193
$171
$152
$134
$118
$103
$90
$78
$67
$58
$50
$43
$36
$31
$27
$23
$20
$17
$14
$17
$0
$0
$3,500
SUM
$0
$0
$229
$464
$715
$1,104
$1,521
$1,429
$1,333
$1,234
$1,132
$1,036
$944
$857
$774
$694
$619
$549
$485
$427
$373
$325
$282
$244
$210
$180
$155
$132
$113
$96
$81
$69
$61
$48
$37
$28
$17
$0
$0
$13,000
aThe SCC values are dollar-year and emissions-year specific.
8-60
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Environmental and Health
Impacts
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64Ishinishi, N. Kuwabara, N. Takaki, Y., et al. (1988). Long-term inhalation experiments on diesel exhaust. In:
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68 U.S. EPA (2002). Health Assessment Document for Diesel Engine Exhaust. EPA/600/8-90/057F Office of
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71 Wade, J.F., III, Newman, L.S. (1993) Diesel asthma: reactive airways disease following overexposure to
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72U.S. EPA (2009) 2002 National-Scale Air Toxics Assessment, http://www.epa.gov/ttn/atw/nata2002. Docket
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73 Zhu, Y.; Hinds, W.C.; Kim, S.; Shen, S.; Sioutas, C. (2002) Study of ultrafine particles near a major highway with
heavy-duty diesel traffic. Atmospheric Environment 36: 4323-4335.
74
Lena, T.S; Ochieng, V.; Holguin-Veras, J.; Kinney, P.L. (2002) Elemental carbon and PM2.5 levels in an urban
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75 Soliman, A.S.M.; Jacko, J.B.; Palmer, G.M. (2006) Development of an empirical model to estimate real-world
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76 Davis, M.E.; Smith, T.J.; Laden, F.; Hart, J.E.; Ryan, L.M.; Garshick, E. (2006) Modeling particle exposure in
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77 Miller, T.L.; Fu, J.S.; Hromis, B.; Storey, J.M. (2007) Diesel truck idling emissions - measurements at a PM25 hot
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78 Ramachandran, G.; Paulsen, D.; Watts, W.; Kittelson, D. (2005) Mass, surface area, and number metrics in diesel
occupational exposure assessment. J Environ Monit 7: 728-735.
79U.S. EPA. 2000. Integrated Risk Information System File for Benzene. This material is available electronically at:
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80 International Agency for Research on Cancer, IARC monographs on the evaluation of carcinogenic risk of
chemicals to humans, Volume 29, Some industrial chemicals and dyestuffs, International Agency for Research on
Cancer, World Health Organization, Lyon, France 1982. Docket EPA-HQ-OAR-2010-0162.
81 Irons, R.D.; Stillman, W.S.; Colagiovanni, D.B.; Henry, V.A. (1992) Synergistic action of the benzene metabolite
hydroquinone on myelopoietic stimulating activity of granulocyte/macrophage colony-stimulating factor in vitro,
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82 International Agency for Research on Cancer (IARC). 1987. Monographs on the evaluation of carcinogenic risk
of chemicals to humans, Volume 29, Supplement 7, Some industrial chemicals and dyestuffs, World Health
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83 U.S. Department of Health and Human Services National Toxicology Program 11th Report on Carcinogens
available at: http://ntp.niehs.nih.gov/go/16183.
84Aksoy, M. (1989). Hematotoxicity and carcinogenicity of benzene. Environ. Health Perspect. 82:193-197.
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85 Goldstein, B.D. (1988). Benzene toxicity. Occupational medicine. State of the Art Reviews. 3: 541-554. Docket
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86Rothman, N., G.L. Li, M. Dosemeci, W.E. Bechtold, G.E. Marti, Y.Z. Wang, M. Linet, L.Q. Xi, W. Lu, M.T.
Smith, N. Titenko-Holland, L.P. Zhang, W. Blot, S.N. Yin, and R.B. Hayes (1996) Hematotoxicity among Chinese
workers heavily exposed to benzene. Am. J. Ind. Med. 29: 236-246. Docket EPA-HQ-OAR-2010-0162.
87 U.S. EPA 2002 Toxicological Review of Benzene (Noncancer Effects). Environmental Protection Agency,
Integrated Risk Information System (IRIS), Research and Development, National Center for Environmental
Assessment, Washington DC. This material is available electronically at http://www.epa.gov/iris/subst/0276.htm.
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88 Qu, O.; Shore, R.; Li, G.; Jin, X.; Chen, C.L.; Cohen, B.; Melikian, A.; Eastmond, D.; Rappaport, S.; Li, H.; Rupa,
D.; Suramaya, R.; Songnian, W.; Huifant, Y.; Meng, M.; Winnik, M.; Kwok, E.; Li, Y.; Mu, R.; Xu, B.; Zhang,
X.; Li, K. (2003). HEI Report 115, Validation & Evaluation of Biomarkers in Workers Exposed to Benzene in
China. Docket EPA-HQ-OAR-2010-0162.
89Qu, Q., R. Shore, G. Li, X. Jin, L.C. Chen, B. Cohen, et al. (2002). Hematological changes among Chinese
workers with a broad range of benzene exposures. Am. J. Industr. Med. 42: 275-285. Docket EPA-HQ-OAR-2010-
0162.
90Lan, Qing, Zhang, L., Li, G., Vermeulen, R., et al. (2004). Hematotoxically in Workers Exposed to Low Levels
of Benzene. Science 306: 1774-1776. Docket EPA-HQ-OAR-2010-0162.
91 Turtletaub, K.W. and Mani, C. (2003). Benzene metabolism in rodents at doses relevant to human exposure from
Urban Air. Research Reports Health Effect Inst. Report No.113. Docket EPA-HQ-OAR-2010-0162.
92U.S. EPA. 2002. Health Assessment of 1,3-Butadiene. Office of Research and Development, National Center for
Environmental Assessment, Washington Office, Washington, DC. Report No. EPA600-P-98-001F. This document
is available electronically at http://www.epa.gov/iris/supdocs/buta-sup.pdf. Docket EPA-HQ-OAR-2010-0162.
93U.S. EPA. 2002 "Full IRIS Summary for 1,3-butadiene (CASRN 106-99-0)" Environmental Protection Agency,
Integrated Risk Information System (IRIS), Research and Development, National Center for Environmental
Assessment, Washington, DC http://www.epa.gov/iris/subst/0139.htm. Docket EPA-HQ-OAR-2010-0162.
94 International Agency for Research on Cancer (IARC) (1999) Monographs on the evaluation of carcinogenic risk
of chemicals to humans, Volume 71, Re-evaluation of some organic chemicals, hydrazine and hydrogen peroxide
and Volume 97 (in preparation), World Health Organization, Lyon, France. Docket EPA-HQ-OAR-2010-0162.
95
International Agency for Research on Cancer (IARC) (2008) Monographs on the evaluation of carcinogenic risk
of chemicals to humans, 1,3-Butadiene, Ethylene Oxide and Vinyl Halides (Vinyl Fluoride, Vinyl Chloride and
Vinyl Bromide) Volume 97, World Health Organization, Lyon, France. Docket EPA-HQ-OAR-2010-0162.
96 U.S. Department of Health and Human Services National Toxicology Program 11th Report on Carcinogens
available at: http://ntp.niehs.nih.gov/go/16183.
97Bevan, C.; Stadler, J.C.; Elliot, G.S.; et al. (1996) Subchronic toxicity of 4-vinylcyclohexene in rats and mice by
inhalation. Fundam. Appl. Toxicol. 32:1-10. Docket EPA-HQ-OAR-2010-0162.
98U.S. EPA. 1987. Assessment of Health Risks to Garment Workers and CertainHome Residents fromExposure to
Formaldehyde, Office of Pesticides and Toxic Substances, April 1987. Docket EPA-HQ-OAR-2010-0162.
"Hauptmann, M..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2003. Mortality from lymphohematopoetic
malignancies among workers in formaldehyde industries. Journal of the National Cancer Institute 95: 1615-1623.
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100Hauptmann, M..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2004. Mortality from solid cancers among
workers in formaldehyde industries. American Journal of Epidemiology 159: 1117-1130. Docket EPA-HQ-OAR-
2010-0162.
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Impacts
101 Beane Freeman, L. E.; Blair, A.; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Hoover, R. N.; Hauptmann, M. 2009.
Mortality from lymphohematopoietic malignancies among workers in formaldehyde industries: The National Cancer
Institute cohort. J. National Cancer Inst. 101: 751-761. Docket EPA-HQ-OAR-2010-0162.
102 Pinkerton, L. E. 2004. Mortality among a cohort of garment workers exposed to formaldehyde: an update.
Occup. Environ. Med. 61: 193-200. Docket EPA-HQ-OAR-2010-0162.
103 Coggon, D, EC Harris, J Poole, KT Palmer. 2003. Extended follow-up of a cohort of British chemical workers
exposed to formaldehyde. J National Cancer Inst. 95:1608-1615. Docket EPA-HQ-OAR-2010-0162.
104 Conolly, RB, JS Kimbell, D Janszen, PM Schlosser, D Kalisak, J Preston, and FJ Miller. 2003. Biologically
motivated computational modeling of formaldehyde carcinogenicity in the F344 rat. Tox Sci 75: 432-447. Docket
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105 Conolly, RB, JS Kimbell, D Janszen, PM Schlosser, D Kalisak, J Preston, and FJ Miller. 2004. Human
respiratory tract cancer risks of inhaled formaldehyde: Dose-response predictions derived from biologically-
motivated computational modeling of a combined rodent and human dataset. Tox Sci 82: 279-296. Docket EPA-
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106 Chemical Industry Institute of Toxicology (CUT). 1999. Formaldehyde: Hazard characterization and dose-
response assessment for carcinogenicity by the route of inhalation. CUT, September 28, 1999. Research Triangle
Park, NC. Docket EPA-HQ-OAR-2010-0162.
107 U.S. EPA. Analysis of the Sensitivity and Uncertainty in 2-Stage Clonal Growth Models for Formaldehyde with
Relevance to Other Biologically-Based Dose Response (BBDR) Models. U.S. Environmental Protection Agency,
Washington, D.C., EPA/600/R-08/103, 2008. Docket EPA-HQ-OAR-2010-0162.
108 Subramaniam, R; Chen, C; Crump, K; .et .al. (2008) Uncertainties in biologically-based modeling of
formaldehyde-induced cancer risk: identification of key issues. Risk Anal 28(4): 907-923. Docket EPA-HQ-OAR-
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109 Subramaniam, R; Chen, C; Crump, K; .et .al. (2007). Uncertainties in the CUT 2-stage model for formaldehyde-
induced nasal cancer in the F344 rat: a limited sensitivity analysis-I. Risk Anal 27:1237. Docket EPA-HQ-OAR-
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110 Crump, K; Chen, C; Fox, J; .et .al. (2008) Sensitivity analysis of biologically motivated model for formaldehyde-
induced respiratory cancer in humans. Ann Occup Hyg 52:481-495. Docket EPA-HQ-OAR-2010-0162.
111 Crump, K; Chen, C; Fox, J; .et .al. (2008) Sensitivity analysis of biologically motivated model for formaldehyde-
induced respiratory cancer in humans. Ann Occup Hyg 52:481-495. Docket EPA-HQ-OAR-2010-0162.
112 Subramaniam, R; Chen, C; Crump, K; .et .al. (2007). Uncertainties in the CUT 2-stage model for formaldehyde-
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113 International Agency for Research on Cancer (2006) Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-
2-ol. Monographs Volume 88. World Health Organization, Lyon, France. Docket EPA-HQ-OAR-2010-0162.
114 Agency for Toxic Substances and Disease Registry (ATSDR). 1999. Toxicological profile for Formaldehyde.
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115 WHO (2002) Concise International Chemical Assessment Document 40: Formaldehyde. Published under the
joint sponsorship of the United Nations Environment Programme, the International Labour Organization, and the
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Management of Chemicals. Geneva. Docket EPA-HQ-OAR-2010-0162.
116U.S. EPA (1988). Integrated Risk Information System File of Acetaldehyde. Research and Development,
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117 U. S. Department of Health and Human Services National Toxicology Program 11th Report on Carcinogens
available at: http://ntp.niehs.nih.gov/go/16183.
118 International Agency for Research on Cancer (IARC). 1999. Re-evaluation of some organic chemicals,
hydrazine, and hydrogen peroxide. IARC Monographs on the Evaluation of Carcinogenic Risk of Chemical to
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119 U.S. EPA (1988). Integrated Risk Information System File of Acetaldehyde. This material is available
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120 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Research and Development, National
Center for Environmental Assessment, Washington, DC. This material is available electronically at
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121 Appleman, L.M., R.A. Woutersen, and V.J. Feron. (1982). Inhalation toxicity of acetaldehyde in rats. I. Acute
and subacute studies. Toxicology. 23: 293-297. Docket EPA-HQ-OAR-2010-0162.
122 Myou, S.; Fujimura, M; Nishi K.; Ohka, T.; and Matsuda, T. (1993) Aerosolized acetaldehyde induces
histamine-mediated bronchoconstriction in asthmatics. Am. Rev. Respir.Dis. 148(4 Pt 1): 940-943. Docket EPA-
HQ-OAR-2010-0162.
123 U.S. EPA. (2003) Toxicological review of acrolein in support of summary information on Integrated Risk
Information System (IRIS) National Center for Environmental Assessment, Washington, DC. EPA/635/R-03/003. p.
10. Available online at: http://www.epa.gov/ncea/iris/toxreviews/0364tr.pdf. Docket EPA-HQ-OAR-2010-0162.
124 U.S. EPA. (2003) Toxicological review of acrolein in support of summary information on Integrated Risk
Information System (IRIS) National Center for Environmental Assessment, Washington, DC. EPA/635/R-03/003.
Available online at: http://www.epa.gov/ncea/iris/toxreviews/0364tr.pdf. Docket EPA-HQ-OAR-2010-0162.
125 U.S. EPA. (2003) Toxicological review of acrolein in support of summary information on Integrated Risk
Information System (IRIS) National Center for Environmental Assessment, Washington, DC. EPA/635/R-03/003. p.
11. Available online at: http://www.epa.gov/ncea/iris/toxreviews/0364tr.pdf. Docket EPA-HQ-OAR-2010-0162.
126 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Office of Research and Development,
National Center for Environmental Assessment, Washington, DC. This material is available at
http://www.epa.gov/iris/subst/0364.htm. Docket EPA-HQ-OAR-2010-0162.
127 U.S. EPA. (2003) Toxicological review of acrolein in support of summary information on Integrated Risk
Information System (IRIS) National Center for Environmental Assessment, Washington, DC. EPA/635/R-03/003. p.
15. Available online at: http://www.epa.gov/ncea/iris/toxreviews/0364tr.pdf. Docket EPA-HQ-OAR-2010-0162.
128 Morris JB, Symanowicz PT, Olsen JE, et al. 2003. Immediate sensory nerve-mediated respiratory responses to
irritants in healthy and allergic airway-diseased mice. J ApplPhysiol 94(4): 1563-1571. Docket EPA-HQ-OAR-
2010-0162.
129 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Research and Development, National
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130 International Agency for Research on Cancer (IARC). 1995. Monographs on the evaluation of carcinogenic risk
of chemicals to humans, Volume 63. Dry cleaning, some chlorinated solvents and other industrial chemicals, World
Health Organization, Lyon, France. Docket EPA-HQ-OAR-2010-0162.
131 Perera, P.P.; Rauh, V.; Tsai, W-Y.; et al. (2002) Effect of transplacental exposure to environmental pollutants on
birth outcomes in a multiethnic population. Environ Health Perspect. Ill: 201-205. Docket EPA-HQ-OAR-2010-
0162.
132 Perera, P.P.; Rauh, V.; Whyatt, R.M.; Tsai, W.Y.; Tang, D.; Diaz, D.; Hoepner, L.; Barr, D.; Tu, Y.H.; Camann,
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133 U. S. EPA. 1998. Toxicological Review of Naphthalene (Reassessment of the Inhalation Cancer Risk),
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Impacts
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134 Oak Ridge Institute for Science and Education. (2004). External Peer Review for the IRIS Reassessment of the
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135 National Toxicology Program (NTP). (2004). 11th Report on Carcinogens. Public Health Service, U.S.
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136 International Agency for Research on Cancer (IARC). (2002). Monographs on the Evaluation of the
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137 U. S. EPA. 1998. Toxicological Review of Naphthalene, Environmental Protection Agency, Integrated Risk
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This material is available electronically at http://www.epa.gov/iris/subst/0436.htm
138 Zhou, Y.; Levy, J.I. (2007) Factors influencing the spatial extent of mobile source air pollution impacts: a meta-
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139 HEI Panel on the Health Effects of Air Pollution. (2010) Traffic -related air pollution: a critical review of the
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140 Salam, M.T.; Islam, T.; Gilliland, F.D. (2008) Recent evidence for adverse effects of residential proximity to
traffic sources on asthma. Current Opin Pulm Med 14: 3-8. Docket EPA-HQ-OAR-2010-0162.
141 Holguin, F. (2008) Traffic, outdoor air pollution, and asthma. Immunol Allergy Clinics North Am 28: 577-588.
142 Adar, S.D.; Kaufman, J.D. (2007) Cardiovascular disease and air pollutants: evaluating and improving
epidemiological data implicating traffic exposure. InhalToxicol 19: 135-149. Docket EPA-HQ-OAR-2010-0162.
143 Raaschou-Nielsen, O.; Reynolds, P. (2006) Air pollution and childhood cancer: a review of the epidemiological
literature. IntJ Cancer 118: 2920-2929. Docket EPA-HQ-OAR-2010-0162.
144 U.S. Census Bureau (2008) American Housing Survey for the United States in 2007. Series H-150 (National
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145 Lena, T.S.; Ochieng, V.; Carter, M.; Holguin-Veras, J.; Kinney, P.L. (2002) Elemental carbon and PM2.5 levels
in an urban community heavily impacted by truck traffic. Environ Health Perspect 110: 1009-1015. Docket EPA-
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146 Wier, M.; Sciammas, C.; Seto, E.; Bhatia, R.; Rivard, T. (2009) Health, traffic, and environmental justice:
collaborative research and community action in San Francisco, California. Am J Public Health 99: S499-S504.
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147 Forkenbrock, D.J. and L.A. Schweitzer, Environmental Justice and Transportation Investment Policy. Iowa
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148 Appatova, A.S.; Ryan, P.H.; LeMasters, O.K.; Grinshpun, S.A. (2008) Proximal exposure of public schools and
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149 Green, R.S.; Smorodinsky, S.; Kim, J.J.; McLaughlin, R.; Ostro, B. (2004) Proximity of California public schools
to busy roads. Environ Health Perspect 112: 61-66. Docket EPA-HQ-OAR-2010-0162.
150 Houston, D.; Ong, P.; Wu, J.; Winer, A. (2006) Proximity of licensed child care facilities to near-roadway vehicle
pollution. Am J Public Health 96: 1611-1617. Docket EPA-HQ-OAR-2010-0162.
151 Wu, Y.; Batterman, S. (2006) Proximity of schools in Detroit, Michigan to automobile and truck traffic. J
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152 U.S. EPA (2009). Integrated Science Assessment for Paniculate Matter (Final Report). U.S. Environmental
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153 U.S. EPA. 1999. The Benefits and Costs of the Clean Air Act, 1990-2010. Prepared for U.S. Congress by U.S.
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154 U.S. EPA (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. EPA,
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155 Winner, W.E., and C.J. Atkinson. 1986. "Absorption of air pollution by plants, and consequences for growth."
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156U.S. EPA (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. EPA,
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157 Tingey, D.T., and Taylor, G.E. (1982) Variation in plant response to ozone: a conceptual model of physiological
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158U.S. EPA (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. EPA,
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162 Ollinger, S.V., Aber, J.D., Reich, P.B. (1997). Simulating ozone effects on forest productivity: interactions
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163 Winner, W.E. (1994). Mechanistic analysis of plant responses to air pollution. Ecological Applications, 4(4), 651-
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168 Pye, J.M. (1988). Impact of ozone on the growth and yield of trees: A review. Journal of Environmental Quality,
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169U.S. EPA (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. EPA,
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170U.S. EPA (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. EPA,
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171 McBride, J.R., Miller, P.R., Laven, R.D. (1985). Effects of oxidant air pollutants on forest succession in the
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172 Miller, P.R., O.C. Taylor, R.G. Wilhour. 1982. Oxidant air pollution effects on a western coniferous forest
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173U.S. EPA (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. EPA,
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174Kopp, R. I, Vaughn, W. I, Hazilla, M., Carson, R. (1985). Implications of environmental policy for U.S.
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175 Adams, R. M., Hamilton, S. A., McCarl, B. A. (1986). The benefits of pollution control: the case of ozone and
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176 Adams, R. M., Glyer, J. D., Johnson, S. L., McCarl, B. A. (1989). A reassessment of the economic effects of
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177 Abt Associates, Inc. 1995. Urban ornamental plants: sensitivity to ozone and potential economic losses. U.S.
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178U.S. EPA (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. EPA,
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179 Grulke, N.E. (2003). The physiological basis of ozone injury assessment attributes in Sierran conifers. In A.
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180 White, D., Kimerling, A.J., Overton, W.S. (1992). Cartographic and geometric component of a global sampling
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181 Smith, G., Coulston, J., Jepsen, E., Prichard, T. (2003). A national ozone biomonitoring program—results from
field surveys of ozone sensitive plants in Northeastern forests (1994-2000). Environmental Monitoring and
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182 White, D., Kimerling, A.J., Overton, W.S. (1992). Cartographic and geometric component of a global sampling
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183 Smith, G., Coulston, J., Jepsen, E., Prichard, T. (2003). A national ozone biomonitoring program—results from
field surveys of ozone sensitive plants in Northeastern forests (1994-2000). Environmental Monitoring and
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184 Coulston, J.W., Riitters, K.H., Smith, G.C. (2004). A preliminary assessment of the Montreal process indicators
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185 U.S. EPA. (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants. EPA/600/R-05/004aF-
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186 Smith, G., Coulston, J., Jepsen, E., Prichard, T. (2003). A national ozone biomonitoring program—results from
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187 U.S. EPA (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants. EPA/600/R-05/004aF-cF.
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188 US EPA. (2007) Review of the National Ambient Air Quality Standards for Ozone: Policy assessment of
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189 Chappelka, A.H., Samuelson, L.J. (1998). Ambient ozone effects on forest trees of the eastern United States: a
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190 U.S. EPA (2009). Integrated Science Assessment for Paniculate Matter (Final Report). U.S. Environmental
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191 U.S. EPA (2005) Review of the National Ambient Air Quality Standard for Paniculate Matter: Policy
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192 U.S. EPA, 2008. Integrated Science Assessment for Oxides of Nitrogen and Sulfur- Ecological Criteria (Final).
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193 U.S. EPA, 2008. Integrated Science Assessment for Oxides of Nitrogen and Sulfur- Ecological Criteria (Final).
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194 Environmental Protection Agency (2003). Response Of Surface Water Chemistry to the Clean Air Act
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195 Fenn, M.E. and Blubaugh, TJ. (2005) Winter Deposition of Nitrogen and Sulfur in the Eastern Columbia River
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196 Galloway, J. N.; Cowling, E. B. (2002). Reactive nitrogen and the world: 200 years of change. Ambio 31: 64-71.
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197 Bricker, Suzanne B., et al., National Estuarine Eutrophication Assessment, Effects of Nutrient Enrichment in the
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198 Smith, W.H. 1991. "Air pollution and Forest Damage." Chemical Engineering News, 69(45): 30-43. Docket
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199 Gawel, J.E.; Ahner, B.A.; Friedland, A.J.; and Morel, F.M.M. 1996. "Role for heavy metals in forest decline
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200 Cotrufo, M.F.; DeSanto, A.V.; Alfani, A.; et al. 1995. "Effects of urban heavy metal pollution on organic matter
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201 Niklinska, M.; Laskowski, R.; Maryanski, M. 1998. "Effect of heavy metals and storage time on two types of
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202 U.S. EPA (2009). Integrated Science Assessment for Paniculate Matter (Final Report). U.S. Environmental
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203 Mason, R.P. and Sullivan, K.A. 1997. "Mercury in Lake Michigan." Environmental Science & Technology, 31:
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204 Landis, M.S. and Keeler, G. J. 2002. "Atmospheric mercury deposition to Lake Michigan during the Lake
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205 U.S. EPA. 2000. EPA453/R-00-005, "Deposition of Air Pollutants to the Great Waters: Third Report to
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206 National Science and Technology Council (NSTC) 1999. "The Role of Monitoring Networks in the Management
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207 Callender, E. and Rice, K.C. 2000. "The Urban Environmental Gradient: Anthropogenic Influences on the Spatial
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208 Rice, K.C. 1999. "Trace Element Concentrations in Streambed Sediment Across the Conterminous United
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209 Ely, JC; Neal, CR; Kulpa, CF; et al. 2001. "Implications of Platinum-Group Element Accumulation along U.S.
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210U.S. EPA. 1998. EPA454/R-98-014, "Locating and Estimating Air Emissions from Sources of Polycyclic
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211 U.S. EPA. 1998. EPA454/R-98-014, "Locating and Estimating Air Emissions from Sources of Polycyclic
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212 Simcik, M.F.; Eisenreich, S.J.; Golden, K.A.; et al. 1996. "Atmospheric Loading of Polycyclic Aromatic
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213 Simcik, M.F.; Eisenreich, S.J.; and Lioy, PJ. 1999. "Source apportionment and source/sink relationship of PAHs
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214 Arzayus, K.M.; Dickhut, R.M.; and Canuel, E.A. 2001. "Fate of Atmospherically Deposited Polycyclic Aromatic
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215 Park, J.S.; Wade, T.L.; and Sweet, S. 2001. "Atmospheric distribution of polycyclic aromatic hydrocarbons and
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216Poor, N.; Tremblay, R.; Kay, H.; et al. 2002. "Atmospheric concentrations and dry deposition rates of polycyclic
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217 Arzayus, K.M.; Dickhut, R.M.; and Canuel, E.A. 2001. "Fate of Atmospherically Deposited Polycyclic Aromatic
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218 U.S. EPA. 2000. EPA453/R-00-005, "Deposition of Air Pollutants to the Great Waters: Third Report to
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219 Van Metre, P.C.; Mahler, B.J.; and Furlong, E.T. 2000. "Urban Sprawl Leaves its PAH Signature."
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221 Tuhackova, J. et al. (2001) Hydrocarbon deposition and soil microflora as affected by highway traffic.
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222 U.S. EPA. 1991. Effects of organic chemicals in the atmosphere on terrestrial plants. EPA/600/3-91/001. Docket
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223 Cape JN, ID Leith, J Binnie, J Content, M Donkin, M Skewes, DN Price AR Brown, AD Sharpe. 2003. Effects
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224 Cape JN, ID Leith, J Binnie, J Content, M Donkin, M Skewes, DN Price AR Brown, AD Sharpe. 2003. Effects
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225 Viskari E-L. 2000. Epicuticular wax of Norway spruce needles as indicator of traffic pollutant deposition. Water,
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226 Ugrekhelidze D, F Korte, G Kvesitadze. 1997. Uptake and transformation of benzene and toluene by plant leaves.
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227 Kammerbauer H, H Selinger, R Rommelt, A Ziegler-Jons, D Knoppik, B Hock. 1987. Toxic components of
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228 U.S. EPA. (2007). PM2.5 National Ambient Air Quality Standard Implementation Rule (Final). Washington,
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229PM Standards Revision- 2006: Timeline. Docket EPA-HQ-OAR-2010-0162.
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230 U. S. Environmental Protection Agency (2007). Control of Hazardous Air Pollutants from Mobile Sources; Final
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233 U. S. Environmental Protection Agency (2007). Control of Hazardous Air Pollutants from Mobile Sources; Final
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234 US EPA (2007) Control of Hazardous Air Pollutants from Mobile Sources Regulatory Impact Analysis. EPA
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235 U.S. Environmental Protection Agency, Byun, D.W., and Ching, J.K.S., Eds, 1999. Science algorithms of EPA
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236 Byun, D.W., and Schere, K.L., 2006. Review of the Governing Equations, Computational Algorithms, and Other
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237 Dennis, R.L., Byun, D.W., Novak, J.H., Galluppi, K.J., Coats, C.J., and Vouk, M.A., 1996. The next generation
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238 Carton, A., Bhave, P., Napelnok, S., Edney, E., Sarwar, G., Finder, R., Pouliot, G., and Houyoux, M. Model
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239 US EPA (2007). Regulatory Impact Analysis of the Proposed Revisions to the National Ambient Air Quality
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240 Allen, D. et al (2009). Report on the Peer Review of the Atmospheric Modeling and Analysis Division, National
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242 Grell, G., Dudhia, I, Stauffer, D. (1994). A Description of the Fifth-Generation Penn State/NCAR Mesoscale
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248 Information on BenMAP, including downloads of the software, can be found at http://www.epa.gov/ttn/ecas/
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249 Bell, M.L., et al. (2004). Ozone and short-term mortality in 95 US urban communities, 1987-2000. JAMA, 2004.
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250 Huang, Y.; Dominici, F.; Bell, M. L. (2005) Bayesian hierarchical distributed lag models for summer ozone
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251 Schwartz, J. (2005) How sensitive is the association between ozone and daily deaths to control for temperature?
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252 Bell, M.L., F. Dominici, and J.M. Samet. (2005). A meta-analysis of time-series studies of ozone and mortality
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254 Levy, J.I., S.M. Chemerynski, and J.A. Sarnat. (2005). Ozone exposure and mortality: an empiric bayes
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256 Laden, F., J. Schwartz, F.E. Speizer, and D.W. Dockery. (2006). Reduction in Fine Participate Air
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262 Schwartz J. (1994a). PM(10) Ozone, and Hospital Admissions For the Elderly in Minneapolis St Paul,
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268 Moolgavkar, S.H. (2000). Air Pollution and Hospital Admissions for Diseases of the Circulatory System in
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269 Sheppard, L. (2003). Ambient Air Pollution and Nonelderly Asthma Hospital Admissions in Seattle,
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286 Rowe, R.D., and L.G. Chestnut. (1986). Oxidants and Asthmatics in Los Angeles: A Benefits Analysis—
Executive Summary. Prepared by Energy and Resource Consultants, Inc. Report to the U.S. Environmental
Protection Agency, Office of Policy Analysis. EPA-230-09-86-018. Washington, DC.
287 Science Advisory Board. 2001. NATA - Evaluating the National-Scale Air Toxics Assessment for 1996 - an
SAB Advisory, http://www.epa.gov/ttn/atw/sab/sabrev.html.
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In April, 2009, EPA hosted a workshop on estimating the benefits or reducing hazardous air pollutants. This
workshop built upon the work accomplished in the June 2000 Science Advisory Board/EPA Workshop on the
Benefits of Reductions in Exposure to Hazardous Air Pollutants, which generated thoughtful discussion on
approaches to estimating human health benefits from reductions in air toxics exposure, but no consensus was
reached on methods that could be implemented in the near term for a broad selection of air toxics. Please visit
http://epa.gov/air/toxicair/2009workshop.html for more information about the workshop and its associated materials.
289 Brenkert A, S. Smith, S. Kim, and H. Pitcher, 2003: Model Documentation for the MiniCAM. PNNL-14337,
Pacific Northwest National Laboratory, Richland, Washington.
290 Wigley, T.M.L. and Raper, S.C.B. 1992. Implications for Climate And Sea-Level of Revised IPCC Emissions
Scenarios Nature 357, 293-300. Raper, S.C.B., Wigley T.M.L. and Warrick R.A. 1996. in Sea-Level Rise and
Coastal Subsidence: Causes, Consequences and Strategies J.D. Milliman, B.U. Haq, Eds., Kluwer Academic
Publishers, Dordrecht, The Netherlands, pp. 11-45.
291 Wigley, T.M.L. and Raper, S.C.B. 2002. Reasons for larger warming projections in the IPCC Third Assessment
Report J. Climate 15, 2945-2952.
292 Thompson AM, KV Calvin, SJ Smith, GP Kyle, A Volke, P Patel, S Delgado-Arias, B Bond-Lamberty, MA
Wise, LE Clarke and JA Edmonds. 2010. "RCP4.5: A Pathway for Stabilization of Radiative Forcing by 2100."
Climatic Change (in review)
293 Clarke, L., J. Edmonds, H. Jacoby, H. Pitcher, J. Reilly, R. Richels, (2007) Scenarios of Greenhouse Gas
Emissions and Atmospheric Concentrations. Sub-report 2.1 A of Synthesis and Assessment Product 2.1 by the U.S.
Climate Change Science Program and the Subcommittee on Global Change Research (Department of Energy, Office
of Biological & Environmental Research, Washington, DC., USA, 154 pp.).
294 Wigley, T.M.L. 2008. MAGICC 5.3.v2 User Manual. UCAR - Climate and Global Dynamics Division, Boulder,
Colorado, http://www.cgd.ucar.edu/cas/wigley/magicc/
295 Meehl, G. A. et al. (2007) Global Climate Projections. In: Climate Change 2007: The Physical Science Basis.
Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate
Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)].
Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
296 Meehl, G. A. et al. (2007) Global Climate Projections. In: Climate Change 2007: The Physical Science Basis.
Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate
Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)].
Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
297 Lewis, E., and D. W. R. Wallace. 1998. Program Developed for CO2 System Calculations. ORNL/CDIAC-105.
Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak
Ridge, Tennessee.
298 Lewis, E., and D. W. R. Wallace. 1998. Program Developed for CO2 System Calculations. ORNL/CDIAC-
105. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy,
Oak Ridge, Tennessee.
299 Mehrbach, C., C. H. Culberson, J. E. Hawley, and R. N. Pytkowicz. 1973. Measurement of the apparent
dissociation constants of carbonic acid in seawater at atmospheric pressure. Limnology and Oceanography 18:897-
907.
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Impacts
300 Dickson, A. G. and F. J. Millero. 1987. A comparison of the equilibrium constants for the dissociation of
carbonic acid in seawater media. Deep-Sea Res. 34, 1733-1743. (Corrigenda. Deep-Sea Res. 36, 983).
301 A. G. Dickson. 1990. Thermodynamics of the dissociation of boric acid in synthetic sea water from 273.15 to
318.15 K. Deep-Sea Res. 37, 755-766.
302 Lewis, E., and D. W. R. Wallace. 1998. Program Developed for CO2 System Calculations. ORNL/CDIAC-
105. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy,
Oak Ridge, Tennessee.
303 Khoo, K.H., R. W. Ramette, C.H. Culberson, and R. G. Bates. 1977. Determination of hydrogen ion
concentrations in seawater from 5 to 40°C: Standard potentials at salinities from 20 to 45%o. Analytical Chemistry
49(1): 29-34.
304
Dickson, A. G. 2003. Certificate of Analysis - Reference material for oceanic CO2 measurements (Batch #62,
bottled on August 21, 2003). Certified by Andrew Dickson, Scripps Institution of Oceanography. November 21,
2003.
Dickson, A. G. 2005. Certificate of Analysis - Reference material for oceanic CO2 measurements (Batch #69,
bottled on January 4, 2005). Certified by Andrew Dickson, Scripps Institution of Oceanography. July 12, 2005.
Dickson, A. G. 2009. Certificate of Analysis - Reference material for oceanic CO2 measurements (Batch #100,
bottled on November 13, 2009). Certified by Andrew Dickson, Scripps Institution of Oceanography. February 10,
2010.
305 National Research Council (2009). Hidden Costs of Energy: Unpriced Consequences of Energy Production and
Use. National Academies Press. See docket ID EPA-HQ-OAR-2009-0472-11486.
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Chapter 9: Other Economic and Social Impacts
Chapter 9. Economic and Social Impacts
9.1 Framework for Benefits and Costs
The net benefits of the proposed National Program consist of the effects of the program on:
• the engine and truck program costs,
fuel savings associated with reduced fuel usage resulting from the program,
greenhouse gas emissions,
• other air pollutants,
• noise, congestion, accidents resulting from truck use,
refueling savings,
energy security impacts,
• increased driving due to the "rebound" effect.
At this time some impacts, such as the effects of the rule on public health, are not included in this
analysis. We plan to address as many of these omitted impacts as possible for the final rule.
As discussed in preamble Section VIII. A, this proposal identifies technologies that reduce
fuel costs enough to pay for themselves over short periods of time. Assuming full information,
perfect foresight, perfect competition, and financially rational vehicle producers and buyers,
standard economic theory suggests that, under normal market operations, interactions between
the buyers and producers would lead to incorporation into the vehicles of all cost-effective
technology without government intervention. Unlike in the light-duty vehicle market, the vast
majority of vehicles in the medium- and heavy-duty truck market are purchased and operated by
businesses; for them, fuel costs may represent substantial operating expenses. Even in the
presence of uncertainty and imperfect information - conditions that hold to some degree in every
market - we generally expect firms to be cost-minimizing to survive in a competitive
marketplace and to make decisions that are therefore in the best interest of the company and its
owners and/or shareholders. In this case, the benefits of the rule would be due to external
benefits. The analysis in Chapter 7 of this draft RIA nevertheless is based on the observation
that fuel savings that appear to be cost-effective in our analysis have not been generally adopted.
As discussed in preamble Section VIII. A., several explanations have been offered for
why there appear to be cost-effective fuel-saving technologies that are not generally adopted. In
the original sales market, there appears to be poor information available about the effectiveness
of fuel-saving technologies for new vehicles. The SmartWay program has helped to improve the
reliability of information, but the technological diffusion process appears to be gradual even
when information is well demonstrated. Similar issues arise in the resale market, where lack of
trust in information about the effectiveness of fuel-saving technology may lead to lack of
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Draft Regulatory Impact Analysis
willingness to pay for fuel-saving technology. This inability to recover some of the value of
fuel-saving technology in the resale market may contribute to the observed very short payback
periods that original equipment buyers expect. It also appears that market coordination is
incomplete. Different agents in the market, such as those who buy trucks and those who pay for
operating costs, may not coordinate their activities; those who buy trucks may not fully consider
the effects of their activities on those who incur fuel expenses. Finally, future fuel savings are
uncertain due, among other factors, to fluctuating fuel prices, while technology costs are
immediate and certain; risk-averse or loss-averse truck purchasers may put more emphasis on the
immediate costs than the uncertain future benefits when deciding what vehicles to purchase.
Several of these explanations, including imperfect information and split incentives, imply
problems in the markets for trucks. Uncertainty and loss aversion reflect buyers' preferences;
requiring them to buy additional fuel-saving technology may affect the utility they receive from
purchasing trucks. These factors could also influence the extent of any increases in VMT due to
the "rebound effect" (discussed below), as well as any impacts on fleet turnover.
Preamble Section VIII.A. discusses these explanations in more detail. We seek comment
on these and other explanations for why our analysis shows cost-effective fuel-saving
technologies that truck purchasers have not adopted.
The costs estimates include the costs of holding other vehicle attributes, such as
performance, constant. The 2010 light-duty GHG/CAFE rule, discussed that if other vehicle
attributes are not held constant, then the cost estimates do not capture the impacts of these
changes.l The light duty rule also discussed other potential issues that could affect the
calculation of the welfare impacts of these types of changes, such as behavioral issues affecting
the demand for technology investments and investment horizon uncertainty. The agencies seek
comments, including supporting data and quantitative analyses, if possible, of any additional
impacts of the proposed standards on vehicle attributes and performance, and other potential
aspects that could positively or negatively affect the welfare implications of this proposed
rulemaking, not addressed in this analysis.
9.2 Rebound Effect
The VMT rebound effect refers to the fraction of fuel savings expected to result from an
increase in fuel efficiency that is offset by additional vehicle use. If truck shipping costs
decrease as a result of lower fuel costs, an increase in truck VMT may occur. Unlike the light-
duty rebound effect, the medium-duty and heavy-duty rebound effect has not been extensively
studied. Because the factors influencing the medium- and heavy-duty rebound effect are
generally different from those affecting the light-duty rebound effect, much of the research on
the light-duty is not likely to apply to the medium- and heavy- duty sectors. One of the major
differences between the medium- and heavy-duty rebound effect and the light-duty rebound
effect is that heavy-duty trucks are used primarily for commercial and business purposes. Since
these businesses are profit driven, decision makers are highly likely to be aware of the costs and
benefits of different operating and shipping decisions, both in the near-term and long-term.
Therefore, both truck operators and shippers are likely to take into account changes in the overall
operating costs per mile when making operating and shipping decisions that affect truck usage.
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Chapter 9: Other Economic and Social Impacts
Another difference from the light-duty case is that, as discussed in the recent NAS
Report, when calculating the change in trucking costs that causes the rebound effect, all
components of truck operating costs should be considered. The cost of labor and fuel generally
constitute the two largest shares of truck operating costs, depending on the price of petroleum,
distance traveled, type of truck, and commodity (see Figure 9-1).23 In addition, the equipment
depreciation costs associated with the purchase or leasing of the truck is also a significant
component of total operating costs. Even though vehicle purchases are lump-sum costs, they are
likely to be considered as operating costs by trucking firms, and these costs are, in many cases,
expected to be passed onto the final consumers of shipping services. By partially offsetting the
reduction in fuel costs resulting from higher fuel efficiency, higher vehicle purchase or lease
prices could thus help temper the magnitude of the fuel economy rebound effect relative to that
for light-duty vehicles, in which vehicle depreciation costs may not be considered as operating
costs by vehicle owners.
When calculating the net change in operating costs, both the increase in new vehicle costs
and the decrease in fuel costs per mile should be taken into consideration. The higher the net
cost savings, the higher the expected rebound effect. Conversely, if the upfront vehicle costs
outweighed future cost savings and total costs increased, shipping costs would rise, which would
likely result in a decrease in truck VMT. In theory, other cost changes resulting from any
requirement to achieve higher fuel economy, such as changes in maintenance costs or insurance
rates, should also be taken into account, although information on potential changes in these
elements of truck operating costs is extremely limited.
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Draft Regulatory Impact Analysis
Figure 9-1 Average Truck Operating Costs
Reference Gate Total Truck Operating Cost Per IVile
Source: ATRL2008
50.126
$0.036
$0.441
$0.634
$0.019
$0.024
$0.030
$O.C60
$0.062
$0.206
$0.092J
D Fuel-Oil Costs ($/mile)
• Fuel Taxes ($/mile)
IH Truck/Trailer Lease or Purchase
Payments ($/mile)
D Repair and Maintenance ($/mile)
• Truck Insurance Premiums
($/mile)
D Tires ($/mile)
• Licensing and Overweight-
Oversize Permits ($/mile)
n Tolls ($/mile)
• Driver Pay* ($/mile)
• Driver Benefits ($/mile)
El Driver Bonus Payments ($/mile)
The following sections describe the factors affecting the rebound effect, different
methodologies for estimating the rebound effect, and examples of different estimates of the
rebound effect to date. According to the NAS study, it is "not possible to provide a confident
measure of the rebound effect," yet NAS concluded that a rebound effect likely exists and that
"estimates of fuel savings from regulatory standards will be somewhat misestimated if the
rebound effect is not considered." While we believe the medium- and heavy- duty rebound
effect needs to be studied in more detail, we have attempted to capture the potential impact of the
rebound effect in our analysis. For this proposal, we have used a rebound effect for single unit
trucks of 15%, a rebound effect for medium-duty (2b and 3) trucks of 10%, and a rebound effect
for combination tractors of 5%. These VMT impacts are reflected in the estimates of total GHG
and other air pollution reductions presented in Chapter 5 of the draft RIA.
9.2.1 Factors Affecting the Magnitude of the Rebound Effect
The heavy-duty vehicle rebound effect is driven by the interaction of several different
factors. In the short-run, decreasing the fuel cost per mile of operating trucks could lead to a
decrease in delivered prices for products shipped by truck. Lower delivered prices could
9-4
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Chapter 9: Other Economic and Social Impacts
stimulate additional demand for those products, which would then result in an increase in truck
usage and VMT. In the long- run, shippers could reorganize their logistics and distribution
networks to take advantage of lower truck shipping costs. For example, shippers may shift away
from other modes of shipping such as rail, barge, or air. In addition, shippers may also choose to
reduce the number of warehouses, reduce load rates, and make smaller, more frequent shipments,
all of which could also lead to an increase in heavy-duty VMT. Finally, the benefits of the fuel
savings could ripple through the economy which could in turn increase overall demand for goods
and services shipped by trucks, and therefore increase truck VMT.
Conversely, if a fuel economy regulation leads to net increases in the cost of trucking
because fuel savings do not fully offset the increase in upfront vehicle costs, then the price of
trucking services could rise, spurring a decrease in heavy-duty VMT and shift to rail shipping.
These effects would also ripple through the economy.
As discussed in Section 8 of the preamble, the magnitude of the rebound effect is likely
to be determined by the extent of market failures that affect demand for fuel economy in
medium- and heavy-duty fleets, such as split incentives and imperfect information, as well as
rational firm responses to the tradeoff between higher certain upfront vehicle costs and lower but
uncertain future expenditures on fuel.
9.2.2 Options for Quantifying the Rebound Effect
As described in the previous section, the fuel economy rebound effect for heavy-duty
trucks has not been studied as extensively as the rebound effect for light-duty vehicles, and
virtually no research has been conducted on the medium-duty truck rebound effect. In this
proposal, we discuss four options for quantifying the rebound effect.
9.2.2.1 Aggregate Estimates
The aggregate approximation approach quantifies the overall change in truck VMT as a
result of a percentage change in truck shipping prices. This approach relies on estimates of
aggregate price elasticity of demand for trucking services, given a percentage change in trucking
prices, which is generally referred to as an "own price elasticity." Estimates of trucking own-
price elasticities vary widely, and there is no general consensus on the most appropriate values to
use. A 2004 literature survey cited in the recent NAS report found aggregate elasticity estimates
in the range of-0.5 to -1.5.4 In other words, given an own price elasticity of-1.5, a 10%
decrease in trucking prices leads to a 15% increase in demand for truck shipping demand.
However, this survey does not differentiate between studies that quantify change in tons shipped
or ton-miles. In addition, most of the studies find that these elasticity estimates vary
substantially based on the length of the trip and the type of cargo. For example, one study
estimated an own-price elasticity of-0.1 for the lumber sector and -2.3 for the chemical sector.5
The increase in overall truck VMT resulting from the rebound effect implicitly includes
some component of mode shifting. Since there are differences in GHG emissions per ton of
freight moved by different modes (e.g., rail, barge, air) compared to truck, any potential shifting
of freight from one mode to the other could have GHG impacts. Although the total demand for
freight transport is generally determined by economic activity, there is often the choice of
9-5
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Draft Regulatory Impact Analysis
shipping by either truck or other modes when freight is transported. This is because the United
States has both an extensive highway network and extensive rail, waterway and air transport
networks; these networks often closely parallel each other and are often viable choices for freight
transport for many origin and destination pairs within the continent. If rates go down for one
mode, there will be an increase in demand for that mode and some demand will be shifted from
other modes. This "cross-price elasticity" is a measure of the percentage change in demand for
shipping by another mode (e.g., rail) given a percentage change in the price of trucking.
Aggregate estimates of cross-price elasticities also vary widely, and there is no general
consensus on the most appropriate value to use for analytical purposes. The NAS report cites
values ranging from 0.35 to 0.59.6 Other reports provide significantly different cross-price
elasticities, ranging from O.I7 to 2.0. See Figure 9-2.8
9-6
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Chapter 9: Other Economic and Social Impacts
Figure 9-2 Examples of Road Elasticity and Cross Elasticity Estimates
Rtftrtnet
(Qum*i. 1994]
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Source: Christidisand Leduc, 2009
When considering intermodal shift, one of the most relevant kinds of shipments are those
that are competitive between rail and truck modes. These trips include long-haul shipments
greater than 500 miles, which weigh between 50,000 and 80,000 pounds (the legal road limit in
many states). Special kinds of cargo like coal and short-haul deliveries are of less interest
because they are generally not economically transferable between truck and rail modes, and they
would not be expected to shift modes except under an extreme price change. However, the total
volume of ton-miles that could potentially be subject to mode shifting has also not been studied
extensively.
9.2.2.2 Sector-Specific Estimates
Given the limited data available regarding the medium- and heavy- duty rebound effect,
the aggregate approach greatly simplifies many of the assumptions associated with calculations
of the rebound effect. In reality, however, responses to changes in fuel efficiency and new
vehicle costs will vary significantly based on the commodities affected. A detailed, sector
specific approach, would be expected to more accurately reflect changes in the trucking market
given these standards. For example, input-output tables could be used to determine the trucking
cost share of the total delivered price of a product or sector. Using the change in trucking prices
9-7
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Draft Regulatory Impact Analysis
described in the aggregate approach, the product-specific demand elasticities could be used to
calculate the change in sales and shipments for each product. The change in shipment increases
could then be weighted by the share of the trucking industry total, and then summed to get the
total increase in trucking output. A simplifying assumption could then be made that the increase
in output results in an increase in VMT. This type of detailed data has not yet been collected,
therefore we do not have any calculations available for the proposal. While we hope to have this
data available for the final rulemaking, gathering high quality data may take a longer time frame.
We invite the submission of comments or data that could be used as part of this methodology.
9.2.2.3 Econometric Estimates
Similar to the methodology used to estimate the light-duty rebound effect, the heavy-duty
rebound effect could be modeled econometrically by estimating truck demand as a function of
economic activity (e.g., GDP) and different input prices (e.g., vehicle prices, driver wages, and
fuel costs per mile). This type of econometric model could be estimated for either truck VMT or
ton-miles as a measure of demand. The resulting elasticity estimates could then be used to
determine the change in trucking demand, given the change in fuel cost and truck prices per mile
from these standards.
9.2.2.4 Other Modeling Approaches
Regulation of the heavy-duty vehicle industry has been studied in more detail in Europe,
as the European Commission (EC) has considered allowing longer and heavier trucks for freight
transport. Part of the analysis considered by the EC relies on country-specific modeling of
changes in the freight sector that would result from changes in regulations.9 This approach
attempts to explicitly calculate modal shift decisions and impacts on GHG emissions. Although
similar types of analysis have not been conducted extensively in the U.S., research is currently
underway that explores the potential for intermodal shifting in the U.S. For example, Winebrake
and Corbett have developed the Geospatial Intermodal Freight Transportation (GIFT) model,
which evaluates the potential for GHG emissions reductions based on mode shifting, given
existing limitations of infrastructure and other route characteristics in the U.S.10 This model
connects multiple road, rail, and waterway transportation networks and embeds activity-based
calculations in the model. Within this intermodal network, the model assigns various economic,
time-of-delivery, energy, and environmental attributes to real-world goods movement routes.
The model can then calculate different network optimization scenarios, based on changes in
prices and policies.u However, more work is needed in this area to determine whether this type
of methodology is appropriate for the purposes of capturing the rebound effect. We invite
comment on this approach, as well as suggestions on alternative modeling frameworks that could
be used to assess mode shifting, fuel consumption, and the GHG emission implications of these
proposed regulations.
9.2.3 Estimates of the Rebound Effect
The aggregate methodology was used by Cambridge Systematics, Inc. (CSI) to show
several examples of the magnitude of the rebound effect.12 In their paper commissioned by the
NAS in support of the recent medium- and heavy-duty report, CSI calculated an effective
rebound effect for two different technology cost and fuel savings scenarios associated with an
9-8
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Chapter 9: Other Economic and Social Impacts
example Class 8 combination tractor. Scenario 1 increased average fuel economy from 5.59 mpg
to 6.8 mpg, with an additional cost of $22,930. Scenario 2 increased the average fuel economy
to 9.1 mpg, at an incremental cost of $71,630 per vehicle. Both of these scenarios were based on
the technologies and targets from a recent Northeast States Center for a Clean Air Future
(NESCCAF) and International Council on Clean Transportation (ICCT) report.13 The CSI
examples provided estimates using a range of own price elasticities (-0.5 to -1.5) and cross-price
elasticities (0.35 to 0.59) from the literature. For these calculations, CSI assumed 142,706
million miles of truck VMT and 1,852 billion ton-miles were affected. The truck VMT was
based on the Bureau of Transportation Statistics (BTS) highway miles for combination tractors
in 2006, and the rail ton-miles were based on the 2006 BTS total railroad miles. This assumption
may overstate the potential rebound effect, since not all highway miles and rail ton miles are in
direct competition. However, this assumption appears to be reasonable in the absence of more
detailed information on the percentage of total miles and ton-miles that are subject to potential
mode shifting.
For CSI's calculations, all costs except fuel costs and vehicle costs were taken from the
2008 ATRI study. It is not clear from the report how the new vehicle costs were incorporated
into the per mile operating costs calculations. For example, in both the ATRI report and the CSI
report, assumptions about depreciation, useful life, and the opportunity cost of capital are not
explicitly discussed.
Based on these two scenarios, CSI found a rebound effect of 11-31% for Scenario 1 and
5-16% for Scenario 2 when the fuel savings from rail were not taken into account ("First rebound
effect"). When the fuel savings from reduced rail usage were included in the calculations, the
overall rebound effect was between 9-13% for Scenario 1 and 3-15% for Scenario 2 ("Second
Rebound Effect"). See Table 9-1.
CSI included a number of caveats associated with these calculations. Namely, the
elasticity estimates derived from the literature are "heavily reliant on factors including the type
of demand measures analyzed (vehicle-miles of travel, ton-miles, or tons), geography, trip
lengths, markets served, and commodities transported." Furthermore, the CSI example only
focused on Class 8 trucks and did not attempt to quantify the potential rebound effect for any
other truck classes. Finally, these scenarios were characterized as "sketches" and were not
included in the final NAS report. In fact, the NAS report asserted that it is "not possible to
provide a confident measure of the rebound effect", yet concluded that a rebound effect likely
exists and that "estimates of fuel savings from regulatory standards will be somewhat
misestimated if the rebound effect is not considered."
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Draft Regulatory Impact Analysis
Table 9-1 Range of Rebound Effect Estimates from Cambridge Systematics Aggregate Assessment
Scenario 1
(6.8 mpg, $22,930)
Scenario 2
(9.1 mpg, $71,630)
"First Rebound Effect"
(increase in truck VMT
resulting from decrease in
operating costs)
11-31%
5-16%
"Second Rebound Effect"
(net fuel savings when
decreases from rail are
taken into account)
9-13
1 ox
3-15%
As an alternative, using the econometric approach, NHTSA has estimated the rebound
effect in the short-run and long run for single unit (Class 4-7) and combination (Class 8) trucks.
As shown in Table 9-2, the estimates for the long-run rebound effect are larger than the estimates
in the short run, which is consistent with the theory that shippers have more flexibility to change
their behavior (e.g., restructure contracts or logistics) when they are given more time. In
addition, the estimates derived from the national data also showed larger rebound effects
compared to the state data. A
One possible explanation for the difference in the estimates is that the national rebound
estimates are capturing some of the impacts of changes in economic activity. Historically, large
increases in fuel prices are highly correlated with economic downturns, and there may not be
enough variation in the national data to differentiate the impact of fuel price changes from
changes in economic activity. In contrast, some states may see an increase in output when
energy prices increase (e.g., large oil producing states such as Texas and Alaska), therefore the
state data may be more accurately isolating the impact of fuel price changes from that of changes
in economic activity. It is important to note that these estimates of the rebound effect reflect the
partial effects of fuel prices and fuel economy changes on truck usage, but not the effect of truck
prices. Therefore, these estimates do not take into account the partially offsetting impacts of
increases in new vehicle costs that are likely to result from regulations requiring higher fuel
economy. For example, if the increase in new vehicle prices associated with increased fuel
economy offset half of the resulting savings in fuel costs, then the effective rebound effect would
be half of the value shown in Table 9-2.
A NHTSA's estimates of the rebound effect are derived from econometric analysis of national and state VMT data
reported in Federal Highway Administration, Highway Statistics, various editions, Tables VM-1 and VM-4.
Specifically, the estimates of the rebound effect reported in Table 9-2 are ranges of the estimated short-run and
long-run elasticities of annual VMT by single-unit and combination trucks with respect to fuel cost per mile driven.
(Fuel cost per mile driven during each year is equal to average fuel price per gallon during that year divided by
average fuel economy of the truck fleet during that same year.) These estimates are derived from time-series
regression of annual national aggregate VMT for the period 1970-2008 on measures of nationwide economic
activity , including aggregate GDP, the value of durable and nondurable goods production, and the volume of U.S.
exports and imports of goods, and variables affecting the price of trucking services (driver wage rates, truck
purchase prices, and fuel costs), and from regression of VMT for each individual state over the period 1994-2008 on
similar variables measured at the state level.
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Chapter 9: Other Economic and Social Impacts
Table 9-2 Range of Rebound Effect Estimates from NHTSA Econometric Analysis
Truck Type
Single Unit
Combination
National Data
Short Run
13-22%
N/A
Long Run
28-45%
12-14%
State Data
Short Run
3-8%
N/A
Long Run
12-21%
4-5%
As discussed throughout this section, there are multiple methodologies for quantifying
the rebound effect, and these different methodologies produce a large range of potential values of
the rebound effect. However, for the purposes of quantifying the rebound effect for this
rulemaking, we have used a rebound effect with respect to changes in fuel costs per mile on the
lower range of the long-run estimates. Given the fact that the long-run state econometric
estimates are generally more consistent with the aggregate estimates, for this proposal we have
chosen a rebound effect for vocational vehicles of 15% that is within the range of estimates from
both methodologies. Similarly, we have chosen a rebound effect for combination tractors of 5%.
To date, no estimates of the HD pickup truck and van (Class 2b and 3) rebound effect
have been cited in the literature. Since these vehicles are used for very different purposes than
heavy-duty vehicles, it does not necessarily seem appropriate to apply one of the heavy-duty
estimates to the HD pickup trucks and vans. These vehicles are more similar in use to large
light-duty vehicles, so for the purposes of our analysis, we have chosen to apply the light-duty
rebound effect of 10% to this class of vehicles.
9.2.4 Application of the Rebound Effect to VMT Estimates
It should be noted that the NHTSA econometric analysis attempts to isolate the rebound
effect with respect to changes in the fuel cost per mile driven. As described previously, the
rebound effect should be a measure of the change in VMT with respect to the change in overall
operating costs. Therefore, NHTSA's rebound estimates with respect to fuel costs per mile must
be "scaled" to apply to total operating costs. For example, we assumed the elasticity of Class 8
truck use with respect to fuel cost per mile driven is -0.05 (which corresponds to a 5% fuel
economy rebound effect), and that fuel costs average 43% of total truck operating costs;
therefore, the elasticity of truck use with respect to total operating costs is -0.05/0.43 = -0.116.
This calculation would correspond to an "overall" rebound effect value - that is, a rebound effect
with respect to total truck operating costs - of -11.6%. In other words, cutting fuel costs per
mile by 10% would correspond to only a 4.3% decline in total truck operating costs, so the
elasticity of truck use with respect to total operating costs would have to be 2.3 times
(100%/43%) larger than the elasticity of truck use with respect to fuel cost alone, in order to
produce the same response in truck VMT (4%* -0.116= 10%*-0.05). We conducted similar
calculations for 2b/3 trucks assuming fuel costs are on average 25% of total operating costs, and
for vocational vehicles assuming fuel costs are on average 21% of total operating costs.
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Draft Regulatory Impact Analysis
Furthermore, we assumed an "average" incremental technology cost of $9,500 for Class 8
combination tractors, $2,000 for Class 2b and 3 trucks, and $300 for vocational vehicles.6
For the purposes of this proposal, we made several additional simplifying assumptions
when applying the overall rebound effect to each class of truck. For example, we assumed that
per mile vehicle costs were based on the new vehicle cost (e.g., $100,000 for the reference case
Class 8 combination tractor) divided by the total lifetime number of expected vehicle miles (e.g.,
1.26 million miles for a Class 8 combination tractor, 288,000 miles for 2b/3 trucks, and 334,000
miles for vocational vehicles). We recognize that this calculation implicitly assumes that truck
depreciation is strictly a function of usage, and that it does not take into account the opportunity
cost of alternative uses of capital. As a result, the new vehicle cost per mile assumptions used in
these calculations represent a smaller percentage of total operating costs compared to the ATRI
and CSI examples. We expect to refine this assumption between the proposal and final
rulemakings, and invite submission of data on how truck owners and operators incorporate new
vehicle costs into their operating cost per mile calculations.
In the costs and benefits summarized in Chapter 9.5, we have not taken into account any
potential fuel savings or GHG emission reductions from the rail, air or water-borne shipping
sectors due to mode shifting. However, we have provided CSFs example calculations in Table
9-1 and request comment on these values. The rebound effect values used in the cost and benefit
analysis fall within the range of the "second rebound effect" identified in the CSI analysis, which
does account for offsetting savings from reduced rail shipping.
In addition, we have not attempted to capture how current market failures might impact
the rebound effect. The direction and magnitude of the rebound effect in the medium- and
heavy-duty truck market are expected to vary depending on the existence and types of market
failures affecting the fuel economy of the trucking fleet. If firms are already accurately
accounting for the costs and benefits of these technologies and fuel savings, then these
regulations would increase their net costs, because trucks would already include all cost-effective
fuel saving technologies. As a result, the rebound effect would actually be negative and truck
VMT would decrease as a result of these proposed regulations.
However, if firms are not optimizing their behavior today due to factors such as lack of
reliable information (see preamble Section VIII. A. for further discussion), it is more likely that
truck VMT would increase. If firms recognize their lower net costs as a result of these
regulations and pass those costs along to their customers, then the rebound effect would increase
truck VMT. This response assumes that trucking rates include both truck purchase costs and fuel
costs, and that the truck purchase costs included in the rates spread those costs over the full
expected lifetime of the trucks. If those costs are spread over a shorter period, as the expected
B These cost estimates include indirect costs. Due to timing constraints, preliminary estimates were used to calculate
the rebound effect, which differ slightly from the costs presented in Chapter 7. In addition, the same "overall" VMT
rebound effect values were used for Alternatives 2 through 8 as analyzed in Chapter 6, despite the fact that each
alternative results in a different change in incremental technology costs and operating costs. For the final
rulemaking, we plan to estimate the overall VMT rebound effect values for each alternative.
9-12
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Chapter 9: Other Economic and Social Impacts
short payback period implies, then those purchase costs will inhibit reduction of freight rates, and
to the extent that they do so the rebound effect will be proportionally smaller.
As discussed in more detail in preamble Section VIII. A, if there are market failures such
as split incentives, estimating the rebound effect may depend on the nature of the failures. For
example, if the original purchaser cannot fully recoup the higher upfront costs through fuel
savings before selling the vehicle nor pass those costs onto the resale buyer, the firm would be
expected to raise shipping rates. A firm purchasing the truck second-hand might lower shipping
rates if the firm recognizes the cost savings after operating the vehicle, leading to an increase in
VMT. Similarly, if there are split incentives and the vehicle buyer isn't the same entity that
purchases the fuel, than there would theoretically be a positive rebound effect. In this scenario,
fuel savings would lower the net costs to the fuel purchaser, which would result in a larger
increase in truck VMT.
If all of these scenarios occur in the marketplace, their consequences for the rebound
effect will depend on the extent and magnitude of their relative effects, which are also likely to
vary across truck classes (for instance, split incentives may be a much larger problem for Class 7
and 8 combination tractor than they are for heavy-duty pickup trucks).
9.3 Other Economic Impacts
9.3.1 Noise, Congestion, and Accidents
Section 9.2 discusses the likely sign of the rebound effect. If net operating costs of the
vehicle decline, then we expect a positive rebound effect. Increased vehicle use associated with
a positive rebound effect also contributes to increased traffic congestion, motor vehicle
accidents, and highway noise. Depending on how the additional travel is distributed throughout
the day and on where it takes place, additional vehicle use can contribute to traffic congestion
and delays by increasing traffic volumes on facilities that are already heavily traveled during
peak periods. These added delays impose higher costs on drivers and other vehicle occupants in
the form of increased travel time and operating expenses. Because drivers do not take these
added costs into account in deciding when and where to travel, they must be accounted for
separately as a cost of the added driving associated with the rebound effect.
Increased vehicle use due to a positive rebound effect may also increase the costs
associated with traffic accidents. Drivers may take account of the potential costs they (and their
passengers) face from the possibility of being involved in an accident when they decide to make
additional trips. However, they probably do not consider all of the potential costs they impose
on occupants of other vehicles and on pedestrians when accidents occur, so any increase in these
"external" accident costs must be considered as another cost of additional rebound-effect driving.
Like increased delay costs, any increase in external accident costs caused by added driving is
likely to depend on the traffic conditions under which it takes place, since accidents are more
frequent in heavier traffic (although their severity may be reduced by the slower speeds at which
heavier traffic typically moves).
Finally, added vehicle use associated with a positive rebound effect may also increase
traffic noise. Noise generated by vehicles causes inconvenience, irritation, and potentially even
9-13
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Draft Regulatory Impact Analysis
discomfort to occupants of other vehicles, to pedestrians and other bystanders, and to residents or
occupants of surrounding property. Because these effects are unlikely to be taken into account
by the drivers whose vehicles contribute to traffic noise, they represent additional externalities
associated with motor vehicle use. Although there is considerable uncertainty in measuring their
value, any increase in the economic costs of traffic noise resulting from added vehicle use should
be included together with other increased external costs from the rebound effect.
EPA and NHTSA rely on estimates of congestion, accident, and noise costs caused by
pickup trucks and vans, single unit trucks, buses, and combination tractors developed by the
Federal Highway Administration to estimate the increased external costs caused by added
driving due to the rebound effect.14 The FHWA estimates are intended to measure the increases
in costs from added congestion, property damages and injuries in traffic accidents, and noise
levels caused by various classes of trucks that are borne by persons other than their drivers (or
"marginal" external costs). EPA and NHTSA employed estimates from this source previously in
the analysis accompanying the Light-Duty GHG final rule. The agencies continue to find them
appropriate for this analysis after reviewing the procedures used by FHWA to develop them and
considering other available estimates of these values.
FHWA's congestion cost estimates for trucks, which are weighted averages based on the
estimated fractions of peak and off-peak freeway travel for each class of trucks, already account
for the fact that trucks make up a smaller fraction of peak period traffic on congested roads
because they try to avoid peak periods when possible. FHWA's congestion cost estimates focus
on freeways because non-freeway effects are less serious due to lower traffic volumes and
opportunities to re-route around the congestion. The agencies, however, applied the congestion
cost to the overall VMT increase, though the fraction of VMT on each road type used in MOVES
range from 27 to 29 percent of the vehicle miles on freeways for vocational vehicles and 53
percent for combination tractors. The results of this analysis potentially overestimate the
congestions costs associated with increased truck use, and thus lead to a conservative estimate of
benefits.
EPA and NHTSA estimated the costs of additional vocational vehicle travel using a
weighted average of 15 percent of the FHWA estimate for bus costs and 85 percent of the
FHWA estimate for single unit truck costs to reflect the make-up of this segment. The low, mid,
and high cost estimates from FHWA updated to 2008 dollars are included in Table 9-3.
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Chapter 9: Other Economic and Social Impacts
Table 9-3 Low-Mid-High Cost Estimates ($/mile)
Noise
Pickup Truck, Van
Vocational Vehicle
Combination Tractor
High
$0.002
$0.024
$0.052
Middle
$0.001
$0.009
$0.020
Low
$0.000
$0.003
$0.006
Accidents
Pickup Truck, Van
Vocational Vehicle
Combination Tractor
High
$0.082
$0.058
$0.069
Middle
$0.026
$0.019
$0.022
Low
$0.014
$0.010
$0.010
Congestion
Pickup Truck, Van
Vocational Vehicle
Combination Tractor
High
$0.144
$0.324
$0.316
Middle
$0.049
$0.110
$0.107
Low
$0.013
$0.029
$0.028
The agencies are proposing to use FHWA's "Middle" estimates for marginal congestion,
accident, and noise costs caused by increased travel from trucks.15 This approach is consistent
with the current methodology used in the Light-Duty GHG rulemaking analysis. These costs are
multiplied by the annual increases in vehicle miles travelled from the rebound effect to yield the
estimated increases in congestion, accident, and noise externality costs during each future year.
EPA and NHTSA use the aggregate per mile costs, as shown in Table 9-4. Table 9-5
presents total monetized estimates of external costs associated with noise, accidents, and
congestion.
Table 9-4 Combined Costs of Congestion, Accidents and Noise (2008$ per mile)
Pickup Truck, Van
Vocational Vehicle
Combination Tractor
$0.076
$0.138
$0.149
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Draft Regulatory Impact Analysis
Table 9-5: Annual External Costs Associated with the Heavy-Duty Vehicle Proposal (Millions of 2008 dollars)
YEAR
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
NPV, 3%
NPV, 7%
Class 2b&3
$0
$0
$8
$16
$23
$30
$37
$44
$50
$55
$60
$65
$70
$74
$77
$81
$84
$86
$89
$91
$94
$96
$98
$101
$103
$105
$107
$109
$112
$114
$116
$118
$120
$122
$124
$126
$128
$131
$133
$1,606
$746
Vocational
$0
$0
$10
$19
$30
$39
$48
$56
$64
$71
$78
$84
$90
$96
$101
$107
$112
$117
$122
$128
$134
$141
$147
$153
$159
$164
$170
$176
$182
$188
$194
$200
$206
$212
$219
$225
$231
$238
$245
$2,407
$1,070
Combination
$0
$0
$18
$35
$52
$68
$83
$98
$111
$123
$133
$143
$153
$161
$169
$176
$182
$188
$193
$198
$202
$206
$210
$214
$218
$222
$226
$230
$233
$237
$241
$245
$248
$252
$256
$259
$263
$267
$271
$3,439
$1,614
Total
$0
$0
$36
$70
$104
$137
$168
$198
$225
$249
$271
$292
$312
$331
$348
$364
$378
$391
$404
$417
$430
$443
$455
$467
$480
$491
$503
$515
$527
$539
$551
$562
$575
$586
$598
$610
$623
$635
$648
$7,452
$3,429
9.3.2 Savings due to Reduced Refueling Time
Reducing the fuel consumption of heavy-duty trucks will either increase their driving
range before they require refueling, or lead truck manufacturers to offer, and truck purchasers
to
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Chapter 9: Other Economic and Social Impacts
buy, smaller fuel tanks. Keeping the fuel tank the same size will allow truck operators to reduce
the frequency with which drivers typically refuel their vehicles, by extending the upper limit on
the distance they can travel before requiring refueling. Alternatively, if truck purchasers and
manufacturers respond to improved fuel economy by reducing the size of fuel tanks, the smaller
tank will require less time to fill during each refueling stop.
Because refueling time represents a time cost of truck operation, these time savings
should be incorporated into truck purchasers' decisions about how much fuel-saving technology
they purchase as part of their choices of new vehicles. The savings calculated here thus raise the
same questions discussed in preamble VIII. A and draft RIA Section 9.1: does the apparent
existence of these savings reflect failures in the market for fuel economy, or does it reflect costs
that are not addressed in this analysis? The response to these questions could vary across truck
segment. See those sections for further analysis of this question.
No direct estimates of the value of extended vehicle range or reduced fuel tank size are
readily available. Instead, this analysis calculates the reduction in the annual amount of time a
driver of each type of truck will spend filling its fuel tank; this reduced time could result either
from fewer refueling events, if new trucks' fuel tanks stay the same size, or from less time spent
filling the tank during each refueling stop, if new trucks' fuels tank are made proportionately
smaller. As discussed in Section 9.2 in this draft RIA, the average number of miles each type of
truck is driven annually will increase under the proposed regulation, as truck operators respond
to lower fuel costs (the "rebound effect"). The estimates of refueling time with the regulation in
effect allow for this increase in truck use. However, EPA's estimate of the rebound effect does
not account for any reduction in net operating costs from lower refueling time. Because the
rebound effect should measure the change in VMT with respect to the net change in overall
operating costs, refueling time costs would ideally factor into this calculation. The effect of this
omission is expected to be minor because refueling time savings are small relative to the value of
reduced fuel expenditures.
The savings in refueling time are calculated as the total amount of time the driver of a
typical truck in each class will save each year as a consequence of pumping less fuel into the
vehicle's tank. The calculation does not include any reduction in time spent searching for a
fueling station or other time spent at the station; it is assumed that time savings occur only when
truck operators are actually refueling their vehicles.
The calculation uses the reduced number of gallons consumed by truck type and divides
that value by the fuel dispense rate (shown in Table 9-6) to determine the number of house saved
in a given year. The calculation then applies DOT-recommended values of travel time savings to
convert the resulting time savings to their economic value. The DOT-recommended value of
travel time per vehicle-hour for truck drivers is $22.15 in 2008$ (converted from $18.10 in
2000$).16 The inputs used in the analysis are included Table 9-6. The savings associated with
reduced refueling time for trucks of each type throughout it lifetime are shown in Table 9-7. The
aggregate savings associated with reduced refueling time are shown in Table 9-8 for vehicles
sold in 2014 through 2050.
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Draft Regulatory Impact Analysis
Table 9-6: Inputs to Calculate Refueling Time Savings
Fuel Economy
Baseline (mpg)
Fuel Economy
Scenario (mpg)
Fuel Dispensing Rate
(gallon/minute) 1?
HD PICKUP TRUCK
AND VAN
15.3
17.4
10
VOCATIONAL
VEHICLE
9.7
10.5
10
TRACTOR
5.0
5.6
20
Table 9-7: Lifetime Refueling Savings for a 2018MY Truck of Each Type (2008$)
3% Discount Rate
7% Discount Rate
PICKUP
TRUCKS AND
VANS
$64
$50
VOCATIONAL
VEHICLES
$220
$176
TRACTORS
$294
$235
The aggregate savings of the vehicles sold in 2014 through 2050 are listed in Table 9-8.
Table 9-8 Annual Refueling Savings (dollar values in Millions of 2008 dollars)
Year
2012
2013
2014
2015
2016
2017
2018
2020
2030
2040
2050
NPV, 3%
NPV, 7%
CLASS 2B&3
Hours Saved
0
0
11,462
28,880
73,842
146,255
276,082
521,325
1,397,977
1,892,106
2,281,344
Savings
$0
$0
$0
$0.6
$1.6
$3.2
$6.1
$12
$31
$42
$51
$532
$229
VOCATIONAL
Hours Saved
0
0
79,190
154,810
236,421
386,323
527,777
785,283
1,693,263
2,597,856
3,506,131
Savings
$0
$0
$1.8
$3.4
$5.2
$8.6
$12
$17
$38
$58
$78
$730
$316
COMBINATION
Hours Saved
0
0
219,593
432,794
637,785
929,379
1,211,476
1,732,760
3,275,326
4,004,536
4,652,762
Savings
$0
$0
$4.9
$10
$14
$21
$27
$38
$73
$89
$103
$1,267
$584
Total Savings
$0
$0
$6.9
$14
$21
$32
$45
$67
$141
$188
$231
$2,529
$1,129
9.4 The Effect of Safety Standards and Voluntary Safety Improvements on Vehicle
Weight
Safety regulations developed by NHTSA in previous regulations may make compliance
with the proposed standards more difficult or may reduce the projected benefits of the program.
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Chapter 9: Other Economic and Social Impacts
The primary way that safety regulations can impact fuel efficiency and GHG emissions is
through increased vehicle weight, which reduces the fuel efficiency of the vehicle. Using MY
2010 as a baseline, this section discusses the effects of other government regulations on model
year (MY) 2014-2016 medium and heavy-duty vehicle fuel efficiency. At this time, no known
safety standards will affect new models in MY 2017 or 2018. The agency's estimates are based
on cost and weight tear-down studies of a few vehicles and cannot possibly cover all the
variations in the manufacturers' fleets. National Highway Traffic Safety Administration
(NHTSA) requested, and various manufacturers provided, confidential estimates of increases in
weight resulting from safety improvements. Those increases are shown in subsequent tables.
We have broken down our analysis of the impact of safety standards that might affect the
MY 2014-16 fleets into three parts: 1) those NHTSA final rules with known effective dates, 2)
proposed rules or soon to be proposed rules by NHTSA with or without final effective dates, and
3) currently voluntary safety improvements planned by the manufacturers.
9.4.1 Weight Impacts of Required Safety Standards
NHTSA has undertaken several rulemakings in which several standards would become
effective for medium- and heavy-duty (MD/HD) vehicles between MY 2014 and MY 2016. We
will examine the potential impact on MD/HD vehicle weights for MY 2014-2016 using MY
2010 as a baseline.
1. FMVSS 119, Heavy Truck Tires Endurance and High Speed Tests
2. FMVSS 121, Air Brake Systems Stopping Distance
3. FMVSS 214, Motor Coach Lap/Shoulder Belts
4. MD/HD Vehicle Electronic Stability Control Systems
9.4.1.1 FMVSS 119, Heavy Truck Tires Endurance and High Speed Tests
The data in the large truck crash causation study (LTCCS) and the agency's test results
indicate that J and L load range tires are more likely to fail the proposed requirements among the
targeted F, G, H, J and L load range tires.0 As such the J and L load range tires specifically need
to be addressed to meet the proposed requirements since the other load range tires are likely to
pass the requirements. Rubber material improvements such as improving rubber compounds
would be a countermeasure that reduces heat retention and improve the durability of the tires.
Using high tensile strength steel chords in tire bead, carcass and belt would enable a weight
reduction in construction with no strength penalties. The rubber material improvements and
using high tensile strength steel would not add any additional weight to the current production
heavy truck tires. Thus there may not be an incremental weight per vehicle for the period of MY
2014-2016 compared to the MY 2010 baseline. This proposal could become a final rule with an
effective date of MY2016.
9.4.1.2 FMVSS No. 121, Airbrake Systems Stopping Distance
c "Preliminary Regulatory Impact Analysis, FMVSS No. 119, New Pneumatic Tires for Motor Vehicles with a
GVWR of More Than 4,536 kg (10,000 pounds), June 2010.
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Draft Regulatory Impact Analysis
The most recent major final rule was published on July 27, 2009 and became effective on
November 24, 2009 (MY2009) with different compliance dates. The final rule requires the vast
majority of new heavy truck tractors (approximately 99 percent of the fleet) to achieve a 30
percent reduction in stopping distance compared to currently required levels. Three-axel tractors
with a gross vehicle weight rating (GVWR) of 59,600 pounds or less must meet the reduced
stopping distance requirements by August 1, 2011 (MY2011). Two-axle tractors and tractors
with a GVWR above 59,600 pounds must meet the reduced stopping distance requirements by
August 1, 2013 (MY2013). There are several brake systems that can meet the requirements in
the final rule. Those systems include installation of larger S-cam drum brakes or disc brake
systems at all positions, or hybrid disc and larger rear S-cam drum brake systems.
According to the data provided by a manufacturer (Bendix), the heaviest drum brakes
weigh more than the lightest disc brakes while the heaviest disc brakes weigh more than the
lightest drum brakes. For a three-axle tractor equipped with all disc brakes, the total weight
could increase by 212 pounds or could decrease by 134 pounds compared to an all drum braked
tractor depending on which disc or drum brakes are used for comparison. The improved brakes
may add a small amount of weight to the affected vehicle for MY2014-2016 resulting in a slight
increase in fuel consumption.
9.4.1.3 FMVSS No. 208, Motor coach Lap/Shoulder Belts
Based on preliminary results from the agency's cost/weight teardown studies of motor
coach seats, D it is estimated that the weight added by 3-point lap/shoulder belts ranges from 5.96
to 9.95 pounds per 2-person seat. This is the weight only of the seat belt assembly itself and
does not include changing the design of the seat, reinforcing the floor, walls or other areas of the
motor coach. Few current production motor coaches have been installed with lap/shoulder belts
on their seats, and the number could be negligible. Assuming a 54 passenger motor coach, the
added weight for the 3-point lap/shoulder belt assembly is in the range of 161 to 269 pounds (27
* (5.96 to 9.95)) per vehicle. This proposal could become a final rule with an effective date of
MY2016.
9.4.2 Electronic Stability Control Systems (ESC) for Medium- and Heavy-Duty
(MD/HD) Vehicles
The ESC is not currently required in MD/HD vehicles and could be proposed to be
required in the vehicles by NHTSA. FMVSS No. 105, Hydraulic and electric brake systems,
requires multipurpose passenger vehicles, trucks and buses with a GVWR greater than 4,536 kg
(10,000 pounds) to be equipped with an antilock brake system (ABS). All MD/HD vehicles
have a GVWR of more than 10,000 pounds, and these vehicles are required to be installed with
an ABS by the same standard.
The ESC incorporates yaw rate control into the ABS, and yaw is a rotation around the
vertical axis. The ESC system uses several sensors in addition to the sensors used in the ABS,
D Cost and Weight Analysis of Two Motorcoach Seating Systems: One With and One Without Three-Point
Lap/Shoulder Belt Restraints, Ludkes and Associates, July 2010.
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Chapter 9: Other Economic and Social Impacts
which is required in MD/HD vehicles. Those additional sensors could include steering wheel
angle sensor, yaw rate sensor, lateral acceleration sensor and wheel speed sensor. According to
the data provided by Meritor WABCO, the weight of the ESC for the model 4S4M tractor is
estimated to be around 55.494 pounds, and the weight of the ABS only is estimated to be 45.54
pounds. Then the added weight for the ESC for the vehicle is estimated to be 9.954 (55.494 -
45.54) pounds.
9.4.3 Summary - Overview of Anticipated Weight Increases
Table 9-9 summarizes estimates made by the agency regarding the weight added by the
above discussed standards or likely rulemakings. The agency estimates that weight additions
required by final rules and likely NHTSA regulations effective in MY 2016 compared to the MY
2010 fleet will increase motor coach vehicle weight by 171-279 pounds and will increase other
heavy-duty truck weights by a minor 10 pounds.
Table 9-9 Weight Additions Due to Final Rules or Likely NHTSA Regulations: Comparing MY 2016 to the
MY 2010 Baseline Fleet
Standard Number
119
121
208
Motor coaches only
MD/HD Vehicle Electronic
Stability Control Systems
Total
Motor coaches
Total
All other MD/HD vehicles
Added Weight in
pounds
MD/HD Vehicle
0
0(?)
161-269
10
171-279
10
Added Weight in
kilograms
MD/HD Vehicle
0
0(?)
73-122
4.5
77.5-126.5
4.5
9.4.4 Effects of Vehicle Mass Reduction on Safety
NHTSA and EPA have been considering the effect of vehicle weight on vehicle safety for
the past several years in the context of our joint rulemaking for light-duty vehicle CAFE and
GHG standards, consistent with NHTSA's long-standing consideration of safety effects in setting
CAFE standards. Combining all modes of impact, the latest analysis by NHTSA for the MYs
2012-2016 final ruleE found that reducing the weight of the heavier light trucks (LT > 3,870) had
a positive overall effect on safety, reducing societal fatalities.
"Final Regulatory Impact Analysis, Corporate Average Fuel Economy for MY 2012 - MY 2016 Passenger Cars
and Light Trucks", NHTSA, March 2010, (Docket No. NHTSA-2009-0059-0344.1).
9-21
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Draft Regulatory Impact Analysis
In the context of the current rulemaking for HD fuel consumption and GHG standards,
one would expect that reducing the weight of medium-duty trucks similarly would, if anything,
have a positive impact on safety. However, given the large difference in weight between light-
duty vehicles and medium-duty trucks, and even larger difference between light-duty vehicles
and heavy-duty vehicles with loads, the agencies believe that the impact of weight reductions of
medium- and heavy-duty trucks would not have a noticeable impact on safety for any of these
classes of vehicles.
However, the agencies recognize that it is important to conduct further study and research
into the interaction of mass, size and safety to assist future rulemakings, and we expect that the
collaborative interagency work currently on-going to address this issue for the light-duty vehicle
context may also be able to inform our evaluation of safety effects for the final HD vehicle rule.
We seek comment regarding potential safety effects due to weight reduction in the HD vehicle
context, with particular emphasis on commenters providing supporting data and research for HD
vehicle weight reduction.
9.5 Petroleum and energy security impacts
9.5.1 Impact on U.S. Petroleum Imports
In 2008, U.S. petroleum import expenditures represented 21 percent of total U.S. imports
of all goods and services.18 In 2008, the United States imported 66 percent of the petroleum it
consumed, and the transportation sector accounted for 70 percent of total U.S. petroleum
consumption. This compares roughly to 37 percent of petroleum from imports and 55 percent
consumption of petroleum in the transportation sector in 1975.19 It is clear that petroleum
imports have a significant impact on the U.S. economy. Requiring lower GHG-emitting heavy-
duty vehicles and improved fuel economy in the U.S. is expected to lower U.S. petroleum
imports.
9.5.2 Background on U.S. Energy Security
U.S. energy security is broadly defined as protecting the U.S. economy against
circumstances that result in significant short- and long-term increases in energy costs. Most
discussion of U.S. energy security revolves around the topic of the economic costs of U.S.
dependence on oil imports. The U.S.'s energy security problem is that the U.S. relies on
imported oil from potentially unstable sources. In addition, oil exporters have the ability to raise
the price of oil by exerting monopoly power through the formation of a cartel, the Organization
of Petroleum Exporting Countries (OPEC). Finally, these factors contribute to the vulnerability
of the U.S. economy to episodic oil supply shocks and price spikes. In 2008, U.S. net
expenditures for imports of crude oil and petroleum products were $336 billion (in 2008$, see
Figure 9-3).
9-22
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Chapter 9: Other Economic and Social Impacts
U.S. Expenditures on Crude Oil
§
700
600
500
400
300
200
100
1970 1975 1980 1985 1990 1995 2000 2005
Figure 9-3: U.S. Expenditures on Crude Oil from 1970 through 2008F
One effect of the EPA/NHTSA joint heavy-duty vehicle rule is that it promotes more
efficient use of transportation fuels in the U.S. The result is that it reduces U.S. oil imports,
which reduces both financial and strategic risks associated with a potential disruption in supply
or a spike in the cost of a particular energy source. This reduction in risks is a measure of
improved U.S. energy security. For this rule, an "oil premium" approach is utilized to identify
those energy security related impacts which are not reflected in the market price of oil, and
which are expected to change in response to an incremental change in the level of U.S. oil
imports.
9.5.2.1 Methodology Used to Estimate U.S. Energy Security Benefits
In order to understand the energy security implications of reducing U.S. oil imports, EPA
has worked with Oak Ridge National Laboratory (ORNL), which has developed approaches for
evaluating the social costs and energy security implications of oil use. The energy security
estimates provided below are based upon a methodology developed in a peer-reviewed study
entitled, "The Energy Security Benefits of Reduced Oil Use, 2006-2015," completed in March
2008. This recent study is included as part of the docket for this rulemaking.20 This ORNL
study is an update version of the approach used for estimating the energy security benefits of
U.S. oil import reductions developed in an ORNL 1997 Report by Leiby, Paul N., Donald W.
For historical data through 2006: EIA Annual Energy Review, various editions.
For data 2006-2008: EIA Annual Energy Outlook (AEO) 2009 (Update Reference (Stimulus) Base Case).
See file "aeostimtab_ll.xls" available at http://www.eia.doe.gov/oiaf/servicerpt/stimulus/aeostim.html
9-23
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Draft Regulatory Impact Analysis
Jones, T. Randall Curlee, and Russell Lee, entitled "Oil Imports: An Assessment of Benefits and
Costs:" 21
When conducting this recent analysis, ORNL considered the full cost of importing
petroleum into the U.S. The full economic cost is defined to include two components in addition
to the purchase price of petroleum itself. These are: (1) the higher costs for oil imports resulting
from the effect of U.S. import demand on the world oil price and on OPEC market power (i.e..,
the "demand" or "monopsony" costs); and (2) the risk of reductions in U.S. economic output and
disruption to the U.S. economy caused by sudden disruptions in the supply of imported oil to the
U.S. (i.e., macroeconomic disruption/adjustment costs). Maintaining a U.S. military presence to
help secure stable oil supply from potentially vulnerable regions of the world was not included in
this analysis because its attribution to particular missions or activities is difficult (as discussed
further below).
The literature on the energy security for the last two decades has routinely combined the
monopsony and the macroeconomic disruption components when calculating the total value of
the energy security premium. However, in the context of using a global value for the Social Cost
of Carbon (SCC) the question arises: How should the energy security premium be used when
some benefits from the rule, such as the benefits of reducing greenhouse gas emissions, are
calculated using a global value? Monopsony benefits represent avoided payments by the U.S. to
oil producers in foreign countries that result from a decrease in the world oil price as the U.S.
decreases its consumption of imported oil. Although there is clearly a benefit to the U.S. when
considered from the domestic perspective, the decrease in price due to decreased demand in the
U.S. also represents a loss of income to oil-producing countries.
Given the redistributive nature of this effect, do the negative effects on other countries
"net out" the positive impacts to the U.S.? If this is the case, then the monopsony portion of the
energy security premium should be excluded from the net benefits calculation for the rule.
OMB's Circular A-4 gives guidance in this regard. Domestic pecuniary benefits (or transfers
between buyers and sellers) generally should not be included because they do not represent real
resource costs, though A- 4 notes that transfers to the U.S. from other countries may be counted
as benefits as long as the analysis is conducted from a U.S. perspective. Energy security is
broadly defined as protecting the U.S. economy against circumstances that threaten significant
short- and long-term increases in energy costs. Energy security is inherently a domestic benefit.
Accordingly, it is possible to argue that the use of the domestic monopsony benefit may not
necessarily be in conflict with the use of the global SCC, because the global SCC represents the
benefits against which the costs of our (i.e., the U.S.'s) domestic mitigation efforts should be
judged. In the final analysis, the Agency has determined that using only the macroeconomic
disruption component of the energy security benefit is the appropriate metric for this rule.
Section VIII.I of the preamble contains more discussion of how the monopsony and
macroeconomic disruption/adjustment components are treated for this analysis.
As part of the process for developing the ORNL energy security estimates, EPA
sponsored an independent, expert peer review of the 2008 ORNL study. A report compiling the
peer reviewers' comments is provided in the docket.22 In addition, EPA has worked with ORNL
to address comments raised in the peer review and to develop estimates of the energy security
9-24
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Chapter 9: Other Economic and Social Impacts
benefits associated with a reduction in U.S. oil imports for this heavy-duty vehicle rule. In
response to peer reviewer comments, ORNL modified its model by changing several key
parameters involving OPEC supply behavior, the responsiveness of oil demand and supply to a
change in the world oil price, and the responsiveness of U.S. economic output to a change in the
world oil price.
For this rule, ORNL further updated the energy security premium by incorporating the
most recent oil price forecast and energy market trends in AEO 2010 into its model. In order for
the energy security premium to be used in EPA's MOVES model, ORNL developed energy
security premium estimates for a number of different years; i.e., 2020, 2030, and 2040.
For 2020, ORNL has estimated that the total energy security premium associated with a
reduction of imported oil is $19.66/barrel. On a dollar per gallon basis, energy security benefits
for 2020 are $0.47/gallon. Table 9-10 provides estimates for energy security premium for the
years 2020, 2030 and 2040,° as well as a breakdown of the components of the energy security
premium for each year. The components of the energy security premium and their values are
discussed below.
Table 9-10 Energy Security Premium in 2020, 2030 and 2040
(2008$/Barrel)
YEAR
2020
2030
2040
MONOPSONY
(RANGE)
$12.28
($4. 16 -$23.74)
$12.69
($4.43-23.80)
$12.68
($4.41 -$23.41)
MACROECONOMIC
DISRUPTION/ADJUSTMENT
COSTS
(RANGE)
$7.39
($3.39 -$11.92)
$8.54
($4.10 -$13.60)
$8.99
($4.48 -$14.08)
TOTAL MID-POINT
(RANGE)
$19.66
($10.27 -$30.90)
$21.23
($11.30 -$32.88)
$21.67
($11.54-$31.10)
9.5.2.2 Effect of Oil Use on Long-Run Oil Price, U.S. Import Costs, and
Economic Output
The first component of the full economic costs of importing petroleum into the U.S.
follows from the effect of U.S. import demand on the world oil price over the long-run. Because
the U.S. is a sufficiently large purchaser of foreign oil supplies, its purchases can affect the world
oil price. This monopsony power means that increases in U.S. petroleum demand can cause the
world price of crude oil to rise, and conversely, that reduced U.S. petroleum demand can reduce
G AEO 2010 forecasts energy market trends and values only to 2035. The energy security premia post-2035 are
assumed to be the 2035 estimate.
9-25
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Draft Regulatory Impact Analysis
the world price of crude oil. Thus, one benefit of decreasing U.S. oil purchases, due to the
increased availability and use of other transportation fuels, is the potential decrease in the crude
oil price paid for all crude oil purchased.
The demand or monopsony effect can be readily illustrated with an example. If the U.S.
imports 10 million barrels per day at a world oil price of $50 per barrel, its total daily bill for oil
imports is $500 million. If a decrease in U.S. imports to 9 million barrels per day causes the
world oil price to drop to $49 per barrel, the daily U.S. oil import bill drops to $441 million (9
million barrels times $49 per barrel). While the world oil price only declines $1, the resulting
decrease in oil purchase payments of $59 million per day ($500 million minus $441 million) is
equivalent to an incremental benefit of $59 per barrel of oil imports reduced, or $10 more than
the newly-decreased world price of $49 per barrel. This additional $10 per barrel "import cost
premium" represents the incremental external benefits to the U.S. for avoided import costs
beyond the price paid oil purchases. This additional benefit arises only to the extent that
reduction in U.S. oil imports affects the world oil price. ORNL estimates this component of the
energy security benefit in 2020 to be $12.28/barrel, with a range of $4.16/barrel to $23.74/barrel
of imported oil reduced.
It is important to note that the decrease in global petroleum prices resulting from the
proposed rule could spur increased consumption of petroleum in other sectors and countries,
leading to a small uptick in GHG emissions outside of the United States. This global fuel
consumption increase could offset some portion of the GHG reduction benefits associated with
the rule. EPA has not quantified this increase in global GHG emissions in the draft RIA and
requests comment on whether to do so for the final RIA.
9.5.2.3 Short-Run Disruption Premium from Expected Costs of Sudden Supply
Disruptions
The second component of the oil import premium, "macroeconomic
disruption/adjustment costs," arises from the effect of oil imports on the expected cost of
disruptions. A sudden increase in oil prices triggered by a disruption in world oil supplies has
two main effects: (1) it increases the costs of oil imports in the short run and (2) it can lead to
macroeconomic contraction, dislocation and Gross Domestic Product (GDP) losses. ORNL
estimates the composite estimate of these two factors that comprise the macroeconomic
disruption/adjustment costs premium to be $7.39/barrel in 2020, with a range of $3.39/barrel to
$11.92/barrel of imported oil reduced.
9.5.2.3.1 Macroeconomic Disruption Adjustment Costs
There are two main effects of macroeconomic disruption/adjustment costs. The first is
the short-run price increases with an oil shock. The oil price shock results in a combination of
real resource shortages, costly short-run shifts in energy supply, behavioral and demand
adjustments by energy users, and other response costs. Unlike pure transfers, the root cause of
the disruption price increase is a real resource supply reduction due, for example, to disaster or
war. Regions where supplies are disrupted, such as the U.S., suffer very high costs. Businesses'
and households' emergency responses to supply disruptions and rapid price increases consume
real economic resources.
9-26
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Chapter 9: Other Economic and Social Impacts
While households and businesses can reduce their petroleum consumption, invest in fuel
switching technologies, or use futures markets to insulate themselves in advance against the
potential costs of rapid increases in oil prices, when deciding how extensively to do so, they are
unlikely to account for the effect of their petroleum consumption on the magnitude of costs that
supply interruptions and accompanying price shocks impose on others. As a consequence, the
U.S. economy as a whole will not make sufficient use of these mechanisms to insulate itself from
the real costs of rapid increases in energy prices and outlays that usually accompany oil supply
interruptions. Therefore, the ORNL estimate of macroeconomic disruption and adjustment
costs that the EPA uses to value energy security benefits includes the increased oil import costs
stemming from oil price shocks that are unanticipated and not internalized by advance actions of
U.S. consumers.
The second main effect of macroeconomic disruption/adjustment costs is the
macroeconomic losses during price shocks that reflect both aggregate output losses and
"allocative" losses. The former are a reduction in the level of output that the U.S. economy can
produce fully using its available resources; and the latter stem from temporary dislocation and
underutilization of available resources due to the shock, such as labor unemployment and idle
plant capacity. The aggregate output effect, a reduction in "potential" economic output, will last
so long as the price is elevated. It depends on the extent and duration of any disruption in the
world supply of oil, since these factors determine the magnitude of the resulting increase in
prices for petroleum products, as well as whether and how rapidly these prices return to their pre-
disruption levels.
In addition to the aggregate contraction, there are "allocative" or "adjustment" costs
associated with dislocated energy markets. Because supply disruptions and resulting price
increases occur suddenly, empirical evidence shows they also impose additional costs on
businesses and households which must adjust their use of petroleum and other productive factors
more rapidly than if the same price increase had occurred gradually. Dislocational effects
include the unemployment of workers and other resources during the time needed for their
intersectoral or interregional reallocation, and pauses in capital investment due to uncertainty.
These adjustments temporarily reduce the level of economic output that can be achieved even
below the "potential" output level that would ultimately be reached once the economy's
adaptation to higher petroleum prices is complete. The additional costs imposed on businesses
and households for making these adjustments reflect their limited ability to adjust prices, output
levels, and their use of energy, labor and other inputs quickly and smoothly in response to rapid
changes in prices for petroleum products.
Since future disruptions in foreign oil supplies are an uncertain prospect, each of the
disruption cost components must be weighted by the probability that the supply of petroleum to
the U.S. will actually be disrupted. Thus, the "expected value" of these costs - the product of the
probability that a supply disruption will occur and the sum of costs from reduced economic
output and the economy's abrupt adjustment to sharply higher petroleum prices - is the relevant
measure of their magnitude. Further, when assessing the energy security value of a policy to
reduce oil use, it is only the change in the expected costs of disruption that results from the
policy that is relevant. The expected costs of disruption may change from lowering the normal
(i.e., pre-disruption) level of domestic petroleum use and imports, from any induced alteration in
9-27
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Draft Regulatory Impact Analysis
the likelihood or size of disruption, or from altering the short-run flexibility (e.g., elasticity) of
petroleum use.
In summary, the steps needed to calculate the disruption or security premium are: 1)
determine the likelihood of an oil supply disruption in the future; 2) assess the likely impacts of a
potential oil supply disruption on the world oil price; 3) assess the impact of the oil price shock
on the U.S. economy (in terms of import costs and macroeconomic losses); and 4) determine
how these costs change with oil imports. The value of price spike costs avoided by reducing oil
imports becomes the oil security portion of the premium.
9.5.2.3.2 Cost of Existing U. S. Energy Security Policies
The last often-identified component of the full economic costs of U.S. oil imports are the
costs to the U.S. taxpayers of existing U.S. energy security policies. The two primary examples
are maintaining the Strategic Petroleum Reserve (SPR) and maintaining a military presence to
help secure a stable oil supply from potentially vulnerable regions of the world. The SPR is the
largest stockpile of government-owned emergency crude oil in the world. Established in the
aftermath of the 1973-74 oil embargo, the SPR provides the U.S. with a response option should a
disruption in commercial oil supplies threaten the U.S. economy. It also allows the U.S. to meet
part of its International Energy Agency obligation to maintain emergency oil stocks, and it
provides a national defense fuel reserve. While the costs for building and maintaining the SPR
are more clearly related to U.S. oil use and imports, historically these costs have not varied in
response to changes in U.S. oil import levels. Thus, while SPR is factored into the ORNL
analysis, the cost of maintaining the SPR is excluded.
U.S. military costs are excluded from the analysis performed by ORNL because their
attribution to particular missions or activities is difficult. Most military forces serve a broad
range of security and foreign policy objectives. Attempts to attribute some share of U.S. military
costs to oil imports are further challenged by the need to estimate how those costs might vary
with incremental variations in U.S. oil imports.
9.5.2.4 Modifications to Analysis Based Upon Peer Reviewer Comments
As part of the peer review process, the EPA commissioned ORNL to conduct a number
of sensitivity analyses to address the comments of the peer reviewers. Based upon the peer
reviewer comments, key parameters that influence the "oil import" premium were assessed.
Since not all the comments were in agreement with each other, several ranges of different
parameters were developed for the analyses. These sensitivities used the most recent price
forecasts and energy market trends available at the time the peer review was being conducted
and completed, the AEO 2007 Reference Case. Thus, the results presented below are suggestive
of how the energy security premium is influenced by alternative assumptions of key parameters
that influence world oil markets but are not directly comparable to the oil security premiums
used for the heavy-duty vehicle rule. A summary of the results of the sensitivity analyses
conducted for the peer review process are shown in Table 9-7.
Three key parameters were varied in order to assess their impacts on the oil import
premium: (1) the response of OPEC supply, (2) the combined response of non-U.S., non-OPEC
9-28
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Chapter 9: Other Economic and Social Impacts
demand and supply and (3) the GDP response to a change in the world oil as a result of reduced
U.S. oil imports. The cases used updated supply/demand elasticities for non-U.S./non-OPEC
region after considering more recent estimates than those used in 1997 study. As a result, the
total market responsiveness is greater than previous ORNL estimates. Only relatively small
changes to the world oil price are anticipated from a substantial reduction in U.S. demand, on
average, about $0.70/barrel for every million barrels per day reduction in demand. In the ORNL
framework, OPEC-behavior is treated parametrically, with a wide range of possible responses
represented by a range of supply elasticities. Case One in below refers to the AEO 2007
estimates of energy market trends and uses the elasticity parameters from the original 1997
ORNL study. In Case Two, the OPEC supply elasticities range from 0.25 to 6.0 with a mean
elasticity of 1.76. Case Three alters the distribution of the OPEC supply elasticities so that the
mean elasticity is 2.2 instead of 1.76. With the more elastic OPEC oil supply in Case Three, the
oil premium is lower. Alternatively, a candidate rule for OPEC strategic response behavior,
adapted from a lead article on what behavior maximizes OPEC's long run net revenue in a robust
way,23 would have OPEC responding to preserve its worldwide oil market share. This is
presented as Case Seven. Application of this rule instead of the range of OPEC supply responses
used leads to an estimate of the oil import premium that is between Case Two and Case Three.
The second key parameter that was varied based upon peer reviewer comments was non-
OPEC, non-U.S. demand and supply responsiveness to a change in the U.S. oil import demand
and, hence, the world oil price. In Case Four, the mean non-U.S./non-OPEC demand and supply
elasticities are taken to each be 0.3 in absolute value terms. When combined together, the net
elasticity of import demand from the non-U.S./non-OPEC region is approximately 1.6. Case
Five takes the Case Four assumptions of a more elastic OPEC supply behavior and combines
those assumptions with the 1.6 net elasticity of import demand for the non-U.S./non-OPEC
region. Case Six looks at the consequences of a yet higher net elasticity of import demand —
2.28 — for the non-U.S./non-OPEC region. The impact on the oil import premium is relatively
modest.
Cases Eight and Nine consider a reduced GDP elasticity, the parameter which
summarizes the sensitivity of GDP to oil price shocks. Several reviewers suggested a lower
estimate for this parameter. In response to their comments, a couple of cases were examined
where the GDP elasticity was lowered to 0.032 in comparison to the original ORNL estimate of
0.0495. As anticipated, this change lowered the oil import premium modestly. For example,
compared with Case Four where OPEC supply is more elastic, lowering the GDP elasticity with
respect to the world oil price reduced the oil import premium by roughly $0.40/barrel. This is
because the GDP-dislocation component is only about one-quarter of the total premium, and
there are offsetting changes in other components. The last case examined, Case Nine, looks at
the consequences for the oil import premium with a reduced elasticity of GDP if OPEC attempts
to maintain its share of the world oil market.
Clearly there is an unavoidable degree of uncertainty about the magnitude of marginal
economic costs from the U.S. importation of petroleum, and the size of the oil import premium.
ORNL sought to reflect this with probabilistic risk analysis over key input factors, guided by the
available literature and the best judgment of oil market experts. Cases shown in Table 9-7
explore some reasonable variations in the ranges of input assumptions and the mean oil premium
estimates vary in a fairly moderate range between roughly $11 and $15/barrel of imported oil.
9-29
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Draft Regulatory Impact Analysis
On balance, Case Eight suggested a reasonable and cautious assessment of the premium value to
ORNL, and is ORNL's recommended case. This is based on a review of important driving
factors, the numerical evaluations and simulations over major uncertainties, and taking into
consideration the many comments and suggestion from the reviewers, the EPA and other
Agencies. This recommended case, and the premium range resulting from 90 percent of the
simulated outcomes, encompasses a wide array of perspectives and potential market outcomes in
response to a reduction of U.S. imports.
As mentioned previously, this recommended case relied on the most recent available
projections of the U.S. and world oil market for the next ten years based upon the AEO 2007
Reference Case. OPEC behavior was treated parametrically, with a wide range of possible
responses represented by a wide range of supply elasticities, from small to quite large. This
recommended case recognized that the OPEC response is the most uncertain single element of
this analysis. It could vary between inelastic defense of output levels, or market share, or could
be highly elastic in defense of price, probably at the expense of longer run cartel power and
discounted net profits. The balance between possible elastic and inelastic OPEC response was
essentially even over a fairly wide range of elasticities. ORNL concluded that this is the best
way to estimate OPEC behavior until greater progress can be made in synthesizing what insights
are available from the evolving strategic game-theoretic and empirical research on OPEC
behavior, and advancing that research. An alternative would have been to use OPEC strategic
response behavior to maximize long-run net revenue, which may well correspond to market-
share preservation behavior (e.g., Case Seven), and a somewhat higher premium value.
Finally, ORNL's recommended case used a GDP elasticity range, the parameter which
summarizes the sensitivity of GDP to oil price shocks, which is reduced compared to earlier
estimates, and compared to the full range of historically-based estimates. This helped address
the concerns of those who either question the conclusions of past empirical estimates or expect
that the impacts of oil shocks may well be declining.
9-30
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Chapter 9: Other Economic and Social Impacts
Table 9-11 Summary Results - Oil Import Premium Under Various Cases
(S2007/BBL)
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9-31
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Draft Regulatory Impact Analysis
9.5.2.5 The Impact of Fuel Savings on U.S. Petroleum Imports
EPA used the MOVES model to estimate the reduced consumption in fuel due to this
proposal. A detailed explanation of the MOVES model can be found in Chapter 5 of this draft
RIA.
Based on a detailed analysis of differences in fuel consumption, petroleum imports, and
imports of refined petroleum products and crude oil among the Reference Case, High Economic
Growth, and Low Economic Growth Scenarios presented in AEO 2009, NHTSA and EPA
estimate that approximately 50 percent of the reduction in fuel consumption resulting from
adopting improved fuel GHG standards and fuel economy standards is likely to be reflected in
reduced U.S. imports of refined fuel, while the remaining 50 percent would be expected to be
reflected in reduced domestic fuel refining. Of this latter figure, 90 percent is anticipated to
reduce U.S. imports of crude petroleum for use as a refinery feedstock, while the remaining 10
percent is expected to reduce U.S. domestic production of crude petroleum. Thus, on balance,
each gallon of fuel saved as a consequence of improved fuel heavy-duty GHG standards and fuel
economy standards is anticipated to reduce total U.S. imports of crude petroleum or refined fuel
by 0.95 gallons.H
Based upon the fuel savings estimated by the MOVES model and the 95 percent oil
import factor, the reduction in U.S. oil imports from this rule are estimated for the years 2020,
2030 and 2040 (in millions of barrels per day (MMBD)) in Table 9-12 below.
Table 9-12 U.S. Oil Import Reductions Resulting from the Heavy-Duty Vehicle Rule in 2020, 2030 and 2040
(in MMBD)
12020
0.177
2030
0.357
2040
0.463
For comparison purposes, Table 9-13 shows the U.S. imports of crude oil in 2020 and
2030 as projected by DOE in the Annual Energy Outlook 2010.
i
Table 9-13 Projected U.S. Imports of Crude Oil in 2020 and 2030
(in MMBD)
2020
8.54
2030
8.69
H This figure is calculated as 0.50 + 0.50*0.9 = 0.50 + 0.45 = 0.95.
1 AEO 2010, EIA, Table 127, Projected United States Imported Liquids by Source to 2030.
9-32
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Chapter 9: Other Economic and Social Impacts
9.5.2.6 Energy Security Benefits of this Proposed Program
Using the same methodology as the peer reviewed model, but updating the analysis using
AEO 2010 world oil price values and the estimated fuel savings from the rule using the MOVES
model, EPA has calculated the energy security benefits of the rule for the years 2020, 2030 and
2040. Since the Agency is taking a global perspective with respect to valuing greenhouse gas
benefits from the rule, only the macroeconomic adjustment/disruption portion of the energy
security premium is used in the energy security benefits estimates present below. These results
are shown below in Table 9-14.
Table 9-14 U.S. Energy Security Benefits of the Heavy-Duty Vehicle Rulemaking in 2020, 2030 and 2040
(in millions of $2008)
12020
$479
2030
$1,117
2040
$1,526
9.6 Summary of Benefits and Costs
In this section, the agencies present a summary of costs, benefits, and net benefits of the
proposal. Table 9-15 shows the estimated annual monetized costs of the proposed program for
the indicated calendar years. The table also shows the net present values of those costs for the
calendar years 2012-2050 using both 3 percent and 7 percent discount rates/ In this table, the
aggregate value of fuel savings is calculated using pre-tax fuel prices since savings in fuel taxes
do not represent a reduction in the value of economic resources utilized in producing and
consuming fuel. Note that fuel savings shown here result from reductions in fleet-wide fuel use.
Thus, they grow over time as an increasing fraction of the fleet meets the 2018 standards.
Table 9-15 Estimated Monetized Costs of the Proposed Program (Millions of 2008 dollars)3
Truck/Tractor
Costs
Fuel Savings
(pre-tax)
Quantified
Annual Costs
2020
$2,000
$8,100
$6,100
2030
$1,900
$19,000
$17,100
2040
$2,200
$28,100
$25,900
2050
$2,500
$35,400
$32,900
NPV, YEARS 20 12-
2050, 3% DISCOUNT
RATE
$42,100
-$352,300
-$310,200
NPV, YEARS 20 12-
2050, 7% DISCOUNT
RATE
$22,500
-$152,600
-$130,100
a Technology costs and fuel savings for separate truck segments can be found in Chapter 7.
Table 9-16 presents estimated annual monetized benefits for the indicated calendar years.
The table also shows the net present values of those benefits for the calendar years 2012-2050
1 For the estimation of the stream of costs and benefits, we assume that after implementation of the proposed MY
2014-2017 standards, the 2017 standards apply to each year out to 2050.
9-33
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Draft Regulatory Impact Analysis
using both 3 percent and 7 percent discount rates. The table shows the benefits of reduced CO2
emissions—and consequently the annual quantified benefits (i.e., total benefits)—for each of
four SCC values estimated by the interagency working group. As discussed in Section 8.5, there
are some limitations to the SCC analysis, including the incomplete way in which the integrated
assessment models capture catastrophic and non-catastrophic impacts, their incomplete treatment
of adaptation and technological change, uncertainty in the extrapolation of damages to high
temperatures, and assumptions regarding risk aversion.
In addition, these monetized GHG benefits exclude the value of reductions in non-CC>2
GHG emissions (CH/j, N2O, HFC) expected under this proposal. Although EPA has not
monetized the benefits of reductions in non-CC>2 GHGs, the value of these reductions should not
be interpreted as zero. Rather, the net reductions in non-CC>2 GHGs will contribute to this rule's
climate benefits, as explained in Section III.F of the preamble.
Table 9-16 Monetized Benefits Associated with the Proposed Program (Millions of 2008 dollars)
2020
2030
2040
2050
NPV, YEARS 2012-2050, 3%
DISCOUNT RATEA
NPV, YEARS 2012-2050, 3%
DISCOUNT RATEA
Reduced CO2 Emissions at each assumed SCC valueb
5% (avg SCC)
3% (avg SCC)
2.5% (avg SCC)
3%(95thpercentile)
Energy Security Impacts
(price shock)
Accidents, Noise,
Congestion
Refueling Savings
Non-CO2 GHG Impacts
and
Non-GHG Impacts c'd
$200
$900
$1,500
$2,800
$500
-$200
$100
n/a
$700
$2,300
$3,500
$7,100
$1,100
-$400
$100
n/a
$1,200
$3,600
$5,300
$10,800
$1,500
-$500
$200
n/a
$1,700
$4,900
$7,100
$14,800
$1,800
-$600
$200
n/a
$8,600
$44,000
$74,600
$134,100
$19,800
-$7,500
$2,500
n/a
$8,600
$44,000
$74,600
$134,100
$8,700
-$3,400
$1,100
n/a
Total Annual Benefits at each assumed SCC valueb
5% (avg SCC)
3% (avg SCC)
2.5% (avg SCC)
3%(95thpercentile)
$600
$1,300
$1,900
$3,200
$1,500
$3,100
$4,300
$7,900
$2,400
$4,800
$6,500
$12,000
$3,100
$6,300
$8,500
$16,200
$23,400
$58,800
$89,400
$148,900
$15,000
$50,400
$81,000
$140,500
" Note that net present value of reduced CO2 emissions is calculated differently than other benefits. The same
discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 2.5 percent) is used to
calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail.
* Section 8.5 of the RIA notes that SCC increases over time. Corresponding to the years in this table, the SCC
estimates range as follows: for Average SCC at 5%: $5-$ 16; for Average SCC at 3%: $22-$46; for Average SCC
at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.F also presents these SCC estimates.
0 The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG emissions
expected under this proposal (see RIA Chapter 5). Although EPA has not monetized changes in non-CO2 GHGs,
the value of any increases or reductions should not be interpreted as zero.
d Non-GHG-related health and welfare impacts (related to PM2 5 and ozone exposure) were not estimated for this
proposal, but will be included in the analysis of the final rulemaking.
Table 9-17 presents estimated annual net benefits for the indicated calendar years. The
table also shows the net present values of those net benefits for the calendar years 2012-2050
using both 3 percent and 7 percent discount rates. The table includes the benefits of reduced
9-34
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Chapter 9: Other Economic and Social Impacts
CC>2 emissions (and consequently the annual net benefits) for each of four SCC values
considered by EPA.
Table 9-17 Monetized Net Benefits Associated with the Proposed Program (Millions of 2008 dollars)
Annual Costs3
2020
-$6,100
2030
-$17,100
2040
-$25,900
2050
-$32,900
NPV, 3%
-$310,200
NPV, 7%
-$130,100
Monetized Annual Benefits at each assumed SCC value
5% (avg SCC)
3% (avg SCC)
2.5% (avg SCC)
3%(95thpercentile)
$600
$1,300
$1,900
$3,200
$1,500
$3,100
$4,300
$7,900
$2,400
$4,800
$6,500
$12,000
$3,100
$6,300
$8,500
$16,200
$23,400
$58,800
$89,400
$148,900
$15,000
$50,400
$81,000
$140,500
Monetized Net Benefits at each assumed SCC value
5% (avg SCC)
3% (avg SCC)
2.5% (avg SCC)
3%(95thpercentile)
$6,700
$7,400
$8,000
$9,300
$18,600
$20,200
$21,400
$25,000
$28,300
$30,700
$32,400
$37,900
$36,000
$39,200
$41,400
$49,100
$333,600
$369,000
$399,600
$459,100
$145,100
$180,500
$211,100
$270,600
a Note that negative costs represent savings rather than costs.
EPA also conducted a separate analysis of the total benefits over the model year lifetimes
of the 2014 through 2018 model year trucks/tractors. In contrast to the calendar year analysis
presented in Table 9-15 through Table 9-17, the model year lifetime analysis shows the impacts
of the proposed program on vehicles produced during each of the model years 2014 through
2018 over the course of their expected lifetimes. The net societal benefits over the full lifetimes
of vehicles produced during each of the five model years from 2014 through 2018 are shown in
Table 9-18 and Table 9-19 at both 3 percent and 7 percent discount rates, respectively.
Table 9-18 Monetized Costs, Benefits, and Net Benefits Associated with the Lifetimes of 2014-2018 Model
Year Trucks (Millions of 2008 dollars; 3% Discount Rate)
2014MY
2015MY
2016MY
2017MY
2018MY
SUM
Monetized Costs
Technology Costs
-$1,300
-$1,300
-$1,500
-$1,600
-$2,000
-$7,700
Monetized Benefits at each assumed SCC value
Pre-tax Fuel Savings
Energy Security
Accidents, Noise, Congestion
Refueling Savings
Non-CO2 GHG Impacts and
Non-GHG Impacts ^
Reduced CO2 emissions at each assumed SCC value
5% (avg SCC)
3% (avg SCC)
2.5% (avg SCC)
3% (95th percentile)
$6,100
$400
-$300
$200
n/a
$200
$600
$1,000
$1,900
$6,400
$400
-$300
$200
n/a
$200
$600
$1,000
$2,000
$7,200
$400
-$300
$200
n/a
$200
$700
$1,100
$2,200
$10,700
$600
-$300
$200
n/a
$300
$1,000
$1,600
$3,200
$11,900
$700
-$300
$200
n/a
$300
$1,200
$1,800
$3,500
$42,300
$2,500
-$1,400
$1,100
n/a
$1,200
$4,100
$6,500
$12,800
Monetized Net Benefits at each assumed SCC value
5% (avg SCC)
3% (avg SCC)
2.5% (avg SCC)
3% (95th percentile)
$5,300
$5,700
$6,100
$7,000
$5,600
$6,000
$6,400
$7,400
$6,200
$6,700
$7,100
$8,200
$9,900
$10,600
$11,200
$12,800
$10,800
$11,700
$12,300
$14,000
$38,000
$40,900
$43,300
$49,600
9-35
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Draft Regulatory Impact Analysis
a The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG emissions
expected under this proposal (see RIA Chapter 5). Although EPA has not monetized changes in non-CO2 GHGs,
the value of any increases or reductions should not be interpreted as zero.
b Non-GHG-related health and welfare impacts (related to PM2 5 and ozone exposure) were not estimated for this
proposal, but will be included in the analysis of the final rulemaking.
Table 9-19 Monetized Costs, Benefits, and Net Benefits Associated with the Lifetimes of 2014-2018 Model
Year Trucks (Millions of 2008 dollars; 7% Discount Rate)
2014MY
2015MY
2016MY
2017MY
2018MY
SUM
Monetized Costs
Technology Costs
-$1,300
-$1,300
-$1,500
-$1,600
-$2,000
-$7,700
Monetized Benefits at each assumed SCC value
Pre-tax Fuel Savings
Energy Security
Accidents, Noise, Congestion
Refueling Savings
Non-CO2 GHG Impacts and
Non-GHG Impacts a'b
Reduced CO2 emissions at each assumed SCC value
5% (avg SCC)
3% (avg SCC)
2.5% (avg SCC)
3%(95thpercentile)
$4,500
$300
-$200
$200
n/a
$200
$600
$1,000
$1,900
$4,500
$300
-$200
$200
n/a
$200
$600
$1,000
$2,000
$4,900
$300
-$200
$200
n/a
$200
$700
$1,100
$2,200
$7,000
$400
-$200
$200
n/a
$300
$1,000
$1,600
$3,200
$7,500
$400
-$200
$200
n/a
$300
$1,200
$1,800
$3,500
$28,400
$1,700
-$900
$900
n/a
$1,200
$4,100
$6,500
$12,800
Monetized Net Benefits at each assumed SCC value
5% (avg SCC)
3% (avg SCC)
2.5% (avg SCC)
3% (95th percentile)
$3,700
$4,100
$4,500
$5,400
$3,700
$4,100
$4,500
$5,500
$3,900
$4,400
$4,800
$5,900
$6,100
$6,800
$7,400
$9,000
$6,200
$7,100
$7,700
$9,400
$23,600
$26,500
$28,900
$35,200
a The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG emissions
expected under this proposal (see RIA Chapter 5). Although EPA has not monetized changes in non-CO2 GHGs,
the value of any increases or reductions should not be interpreted as zero.
b Non-GHG-related health and welfare impacts (related to PM2 5 and ozone exposure) were not estimated for this
proposal, but will be included in the analysis of the final rulemaking.
9-36
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Chapter 9: Other Economic and Social Impacts
Reference
1 Environmental Protection Agency and Department of Transportation, "Light-Duty Vehicle Greenhouse Gas
Emissions Standards and Corporate Average Fuel Economy Standards; Final Rule," Federal Register 75(88) (May 7,
2010). See especially sections III.H.l (pp. 25510-25513) and IV.G.6 (pp. 25651-25657).
2 American Transportation Research Institute, An Analysis of the Operational Costs of Trucking, December 2008
(Docket ID: EPA-HQ-OAR-2010-0162-0007).
3 Transport Canada, Operating Cost of Trucks, 2005. See http://www.tc.gc.ca/eng/policv/report-acg-
operatingcost2005-2005-e-2-1727.htm. accessed on July 16, 2010 (Docket ID: EPA-HQ-OAR-2010-0162-0006).
4 Graham and Glaister, "Road Traffic Demand Elasticity Estimates: A Review," Transport Reviews Volume 24, 3,
pp. 261-274, 2004 (Docket ID: EPA-HQ-OAR-2010-0162-0005).
5 Winston, C. (1981). The welfare effects of ICC rate regulation revisited. The Bell Journal of Economics, 12, 232-
244 (Docket ID: EPA-HQ-OAR-2010-0162-0021).
6 Committee to Assess Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles; National Research
Council; Transportation Research Board (2010). Technologies and Approaches to Reducing the Fuel Consumption
of Medium- and Heavy-Duty Vehicles. ("The NAS Report") Washington, D.C., The National Academies Press.
Available electronically from the National Academy Press Website at http://www.nap.edu/catalog. See also 2009
Cambridge Systematics, Inc., Draft Final Paper commissioned by the NAS in support of the medium-duty and
heavy-duty report. Assessment of Fuel Economy Technologies for Medium and Heavy Duty Vehicles:
Commissioned Paper on Indirect Costs and Alternative Approaches (Docket ID: EPA-HQ-OAR-2010-0162-0009).
7 Friedlaender, A. and Spady, R. (1980) A derived demand function for freight transportation, Review of Economics
and Statistics, 62, pp. 432^41 (Docket ID: EPA-HQ-OAR-2010-0162-0004).
8 Christidis and Leduc, "Longer and Heavier Vehicles for freight transport," European Commission Joint Research
Center's Institute for Prospective Technology Studies, 2009 (Docket ID: EPA-HQ-OAR-2010-0162-0010).
9 Christidis and Leduc, 2009.
10 Winebrake, James and James J. Corbett (2010). "Improving the Energy Efficiency and Environmental
Performance of Goods Movement," in Sperling, Daniel and James S. Cannon (2010) Climate and Transportation
Solutions: Findings from the 2009 Asilomar Conference on Transportation and Energy Policy. See
http://www.its.ucdavis.edu/events/2009book/Chapterl3.pdf (Docket ID: EPA-HQ-OAR-2010-0162-0011)
11 Winebrake, J. J.; Corbett, J. J.; Falzarano, A.; Hawker, J. S.; Korfmacher, K.; Ketha, S.; Zilora, S., Assessing
Energy, Environmental, and Economic Tradeoffs in Intermodal Freight Transportation, Journal of the Air & Waste
Management Association, 58(8), 2008 (Docket ID: EPA-HQ-OAR-2010-0162-0008).
12 Cambridge Systematics, Inc.. 2009.
13 Northeast States Center for a Clean Air Future, Southeast Research Institute, TIAX, LLC., and International
Council on Clean Transportation, Reducing Heavy-Duty Long Haul Truck Fuel Consumption and CO2 Emissions,
September 2009. See http://www.nescaum.org/documents/heaw-dutv-truck-ghg report final-200910.pdf
14
These estimates were developed by FHWA for use in its 1997 Federal Highway Cost Allocation Study, see
http://www.fhwa.dot.gov/policy/hcas/fmal/index.htm (last accessed July 21, 2010).
9-37
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Draft Regulatory Impact Analysis
15 See Federal Highway Administration, 1997 Federal Highway Cost Allocation Study,
http://www.fhwa.dot.gov/policy/hcas/final/index.htm, Tables V-22, V-23, and V-24 (last accessed July 21, 2010).
16 See Table 4. Last viewed on September 9, 2010 at http://ostpxweb.dot.gov/policv/Data/VOTrevisionl 2-11-
03.pdf. Note that we assume the value of travel time is constant out to 2050, which is a conservative assumption
since it is likely this value will increase due to income growth in the future.
Passenger vehicle fuel dispensing rate per EPA regulations, last viewed on August 4, 2010 at
http://www. epa. gov/oms/regs/ld-hwy/evap/spitback. txt
18
U.S. Bureau of Economic Analysis, U.S. International Transactions Accounts Data, as shown on June 14, 2010.
iy U.S. Department of Energy, Annual Energy Review 2008, Report No. DOE/EIA-0384(2008), Tables 5.1 and
5.13c, June 26, 2009.
20 Leiby, Paul N. "Estimating the Energy Security Benefits of Reduced U.S. Oil Imports," Oak Ridge National
Laboratory, ORNL/TM-2007/028, Final Report, 2008.
21 Leiby, Paul N., Donald W. Jones, T. Randall Curlee, and Russell Lee, Oil Imports: An Assessment of Benefits and
Costs, ORNL-6851, Oak Ridge National Laboratory, November, 1997.
Peer Review Report Summary: Estimating the Energy Security Benefits of Reduced U.S. Oil Imports, ICF, Inc.,
September 2007.
23 Gately, Dermot 2004. "OPEC's Incentives for Faster Output Growth," The Energy Journal, 25(2):75-96, "What
Oil Export Levels Should We Expect From OPEC?" The Energy Journal, 28(2): 151-173, 2007
9-38
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Small Business Flexibility
Analysis
CHAPTER 10:
Small Business Flexibility Analysis
The Regulatory Flexibility Act, as amended by the Small Business Regulatory
Enforcement Fairness Act of 1996 (SBREFA), generally requires an agency to prepare a
regulatory flexibility analysis for any rule subject to notice-and-comment rulemaking
requirements under the Administrative Procedure Act or any other statute. This requirement
does not apply if the agency certifies that the rule will not have a significant economic impact
on a substantial number of small entities.
The following discussion provides an overview of small entities in the heavy-duty
vehicle and engine market. Small entities include small businesses, small organizations, and
small governmental jurisdictions. For the purposes of assessing the impacts of the rule on
small entities, a small entity is defined as: (1) a small business that meets the definition for
business based on the Small Business Administration's (SBA) size standards (see Table
10-1); (2) a small governmental jurisdiction that is a government of a city, county, town,
school district or special district with a population of less than 50,000; and (3) a small
organization that is any not-for-profit enterprise which is independently owned and operated
and is not dominant in its field. Table 10-1 provides an overview of the primary SBA small
business categories potentially affected by this regulation.
Table 10-1 Primary Small Business NAICS Categories Affected by this Rulemaking
Engine Equipment Manufacturer
Automobile Manufacturer
Light Truck and Utility Vehicle
Manufacturer
Heavy-Duty Truck Manufacturer
Motor Vehicle Body Manufacturing
NAICS CODES1
333618
336111
336112
336120
336211
DEFINED BY SBA AS A
SMALL BUSINESS IF LESS
THAN OR EQUAL TO:2
1,000 employees
1,000 employees
1,000 employees
1,000 employees
1,000 employees
We compiled a list of engine manufacturers, vehicle manufacturers, and body
manufacturers that would be potentially affected by the rule from the EPA database for engine
certification, Ward's Automotive Database, and the MJ. Bradley's Heavy Duty Vehicle
Market Analysis. We then identified companies that appear to meet the definition of small
business provided in the table above based on the number of employees based on company
information included in Hoover's. Based on this assessment, the agencies identified the
following:
• two tractor manufacturers3 which comprise less than 0.5 percent of the total
heavy-duty combination tractors in the U.S. based on Polk Registration Data
from 2003 through 2007;4
10-1
-------
Regulatory Impact Analysis
• ten chassis manufacturers5 less than 0.5 percent of the total heavy-duty
combination tractors in the U.S. based on Polk Registration Data from 2003
through 2007;6 and
• three heavy duty engine manufacturers7 which comprise less than 0.1 percent
of total heavy-duty engine based on 2008 and 2009 model year engine
certification data submitted to EPA for non-GHG emissions standards.
The proposed exemption from the standards established under this proposal would
have a negligible impact on the GHG emissions and fuel consumption reductions otherwise
due to the standards.
EPA has not conducted an Initial Regulatory Flexibility Analysis for this proposed
rulemaking because we are certifying that the rule would not have a significant economic
impact on a substantial number of small entities. EPA is exempting manufacturers, domestic
and foreign, meeting SBA's size definitions of small business as described in 13 CFR
§ 121.201. EPA will instead consider appropriate GHG standards for these entities as part of
a future regulatory action.
To ensure that EPA and NHTSA are aware of which companies would be exempt, the
agencies propose to require that such entities submit a declaration to EPA containing a
detailed written description of how that manufacturer qualifies as a small entity under the
provisions of 13 CFR § 121.201.
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Heavy-Duty GHG and Fuel Efficiency Standards NPRM: Small Business Flexibility
Analysis
References
1 North American Industry Classification System
2 According to SBA's regulations (13 CFR Part 121), businesses with no more than the listed number of
employees or dollars in annual receipts are considered "small entities" for RFA purposes.
3 The agencies have identified Ottawa Truck, Inc. and Kalmar Industries USA as two potential small tractor
manufacturers
4 M.J. Bradley. Heavy Duty Vehicle Market Analysis. May 2009.
5 The agencies have identified Lodal, Indiana Phoenix, Autocar LLC, HME, Giradin, Azure Dynamics,
DesignLine International, Ebus, Krystal Koach, and Millenium Transit Services LLC as potential small business
chassis manufacturers.
6 M.J. Bradley. Heavy Duty Vehicle Market Analysis. May 2009.
7 The agencies have identified Baytech Corporation, Clean Fuels USA, and BAF Technologies, Inc. as three
potential small businesses
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