United States
Environmental Protection
Agency
Washington
D.C. 20460
EPA 400/2-78-002a
March 1978
Air
Air Quality Impacts
of Transit Improvements,
Preferential Lane,
and Carpool/Vanpool
Programs
-------
Air Quality Impacts
of
Transit Improvement,
Preferential Lane,
and
Carpool /Vanpool Programs
FINAL REPORT
prepared for
Environmental Protection Agency
Office of Transportation and Land Use Policy
in cooperation with
U.S. Department of Transportation
EPA Contract No. 68-01-3912
March 1978
-------
EXECUTIVE SUMMARY
OBJECTIVE AND SCOPE
This report has been prepared in accordance with Section 108(f) of the
Clean Air Act, as amended, August 1977. It is intended to assist urban
areas in developing transportation measures for the State Implementation
Plan and integrating their transportation system management and air quali-
ty planning programs as required by the Federal Highway Administration,
the Urban Mass Transportation Administration and the Environmental Pro-
tection Agency.
The specific types of short-range transportation programs examined
this report include:
. priority treatment for high occupancy vehicles on freeways
and arterials;
. areawide carpool and vanpool programs; and
. transit fare reductions and service improvements.
It is important to note that other transportation measures such as in-
spection and maintenance programs for vehicles, parking controls, traffic
operations, and pricing are not covered in this project, but will be the sub-
ject of future EPA information reports.
The report is intended to provide information to help urban areas covered
by EPA's Transportation Planning Guidelines to:
. assess the applicability and potential of the three classes of
TSM programs described above for improving localized and
regional air quality;
. estimate and evaluate the cost-effectiveness of such pro-
grams and their related travel, energy consumption, cost,
and economic impacts; and
. identify key factors (e. g., meteorological conditions, vehi-
cle type distributions and vehicle operating speeds) likely
to affect air quality and air pollution emissions.
This information report addresses the above issues at a sketch planning
scale of analysis. It can thus be used to identify the relative effectiveness,
-------
impacts, and costs of strategies in achieving air quality. Local metropolitan
areas will thereby have a capability to explore a broad range of strategies
for achieving air quality and to assemble the most promising sets of strat-
egies into comprehensive alternative programs. More detailed transporta-
tion and air quality analyses — with appropriate consideration of specific
local circumstances -- will be required to adequately address the effective-
ness, impacts, and costs of the comprehensive alternative programs within
specific urban areas.
ANALYSIS APPROACH
The report includes a summary and assessment of observed and model-
estimated travel impacts associated with the application of reserved free-
way/arterial lane, transit, carpool and vanpool programs based on a com-
prehensive literature review.
Programs within the scope of this project which demonstrated poten-
tial for cost-effectively improving either localized or regional air quality
were selected for detailed analysis and evaluation based on the findings of
the literature review.
In order to quantitatively assess the air quality and related impacts of
interest, twenty prototype scenarios were defined to represent "real-world"
circumstances in which the alternative programs are typically implemented.
The use of prototype scenarios, rather than specific projects which have
been implemented provides a more consistent basis for comparing the cost-
effectiveness and the magnitudes and characteristics of the associated im-
pacts for the programs of interest. Scenarios were formulated to analyze
impacts on both localized (CO) and regional (oxidant) air quality.
FINDINGS
The major findings of the report are summarized below.
Literature Review
Localized Strategies
Based on the findings of the literature review, the strategies which ap-
pear to have the best potential for achieving improvements in localized CO
air quality include:
. With-flow freeway lanes reserved for buses and carpools;
ii
-------
. Contraflow bus lanes on freeways;
. Metered freeway access ramps with bus by-pass lanes;
. Contraflow bus lanes on major one-way arterial pairs;
. Provision of high level express bus service with reduced
fares, operating in mixed traffic on major arterials or
freeways;
. Provision of high level express bus service (possibly with
reduced fares), combined with a reserved lane for buses
and carpools on the appropriate freeway facility; and
. Provision of high level express bus service (possibly with
reduced fares), combined with a reserved median lane for
buses and bus preemption of traffic signals on an appropri-
ate arterial.
Freeway priority strategies can have significant localized (CO) air qual-
ity impacts. For freeway corridors with significant localized CO air quality
problems, strategies giving priority treatment to high occupancy vehicles
may achieve significant improvements, especially when applied as part of
a package of strategies favoring high occupancy vehicles in the corridor.
The arterial strategies which appear to have the highest potential for
reducing CO concentrations are reserved median bus lanes with priority
signalization and contraflow bus lanes on one-way pairs.
Mass transit improvements, such as fare reductions, comprehensive
marketing programs, security and facilities improvements and provision of
new or expanded service may contribute to resolving localized CO problems.
Expanded radial express bus service can have the most significant impact on
air quality, especially when introduced in areas where transit ridership is
low and when combined with strategies giving priority treatment to buses.
While fare reductions and service improvements tend to be costly, the im-
portance of such strategies lies in their inclusion in a comprehensive plan
to improve air quality. Although mass transit improvements by themselves
may not have significant impact on air quality, they are an essential element
of a comprehensive program intended to encourage the use of high occupancy
vehicles and discourage the use of low occupancy vehicles. Thus, it is im-
portant to improve the mass transit system to provide alternative means
for mobility as other programs, such as parking controls, are implemented
to reduce reliance on the private vehicle.
iii
-------
Regional Strategies
To improve regional air quality it is suggested that emphasis be placed
on the analysis of integrated areawide ride-sharing programs directed at
large employers and including carpool matching, vanpool formation assis-
tance, and promotional components. The findings of the literature review
also suggested assessing the regional air quality impacts of implementing
the promising radial corridor strategies in several corridors throughout
the region.
Well-organized areawide carpool matching programs focusing on large
employers may achieve up to five percent reductions in work trip VMT.
Employer oriented carpool programs are generally more effective than de-
centralized areawide programs . Vanpooling programs have also experi-
enced success in certain cases for large employers. With some rare ex-
ceptions, it is unlikely that areawide ride-sharing programs will have sig-
nificant localized air quality impacts.
The air quality impacts of both carpool matching and vanpool programs
can be significantly improved by incorporating ride-sharing incentive and
single occupancy auto disincentive strategies into the overall program.
Such strategies would include preferential parking for pool vehicles, lower
rate or free parking for pool vehicles, and special employer incentives for
employee pool members.
Assessment of Scenarios
Based on the literature review a total of 20 prototype scenarios were
selected for analysis and evaluation. These scenarios were defined to en-
compass the most promising carpool/vanpool, reserved lane, and transit im-
provement strategies and combination programs for improving air quality.
Ten of the scenarios deal with strategies which impact specific highway
corridors, thus affecting only a limited portion of total regional travel. The
analysis of these "localized" scenarios therefore focuses on their carbon
monoxide (CO) concentration impacts near the affected highway facilities.
The remaining ten scenarios have areawide travel impacts. The analysis of
these latter "regional" scenarios thus focuses on their regional pollutant
emission impacts.
The scenarios were designed with some systematic variation in assumed
travel impacts and area size to facilitate generalizing the project's findings.
However, the extent of this planned variation in assumed prototype conditions
was limited by the number of scenarios analyzed in total and the need for a
IV
-------
minimum degree of uniformity among scenarios (so that impact estimates
among different strategies would be comparable).
Localized Scenarios
Exhibit 7 in Section III of this report describes the 10 prototype scenarios
selected for analysis of localized CO concentration impacts. The first eight
localized scenarios deal with the priority treatment of high occupancy vehi-
cles on freeways, while the last two deal with priority treatment of buses on
arterials. The programs being implemented in a scenario typically consist
of several complementary actions, such as reserving a freeway lane, expand-
ing express bus service, and providing park-and-ride lots in the corridor.
As indicated in Section II, such combinations are typical of actual TSM pro-
grams.
Exhibit A summarizes the following impacts of the localized scenarios:
. peak hour vehicle volumes on affected highway facilities;
. peak hour CO concentrations (reflecting vehicle emissions
only) for both typical, good and typical, poor dispersion
conditions; and
. the capital and annual operating and maintenance costs of
the scenarios.
The freeway-based scenarios (Scenarios 1-8) are likely to achieve re-
ductions in overall peak hour corridor traffic volumes ranging between 1. 5
percent and 7 percent. The estimated reductions in peak direction, peak
hour traffic volumes on the freeways in these scenarios ranged between 3 and
15 percent.
The arterial scenarios analyzed (Scenarios 9 and 10) can also promote
4 to 15 percent reductions in peak hour vehicular volumes. As is true for
the freeway scenarios, the attainment of such reductions is highly depen-
dent upon the specific setting in which such strategies may be implemented.
However, the percentage reductions in vehicular volumes for arterials are
based on smaller base volumes and are not fully comparable to the corridor
volumes in the freeway scenarios.
Generally the relative reductions in peak hour CO concentrations (under
typical, good dispersion conditions) showrj in Exhibit A are several percent-
age points higher than the corresponding reductions in peak hour corridor
vehicle volumes but are generally several percentage points lower than the
-------
EXHIBIT A
SUMMARY OF ESTIMATED IMPACTS FOR THE LOCALIZED PROTOTYPE SCENARIOS
PROTOTYPE SCENARIO
10
No.
1
2
3
4
5
6
7
1
1
10
BRIEF TITLE
Expanded Express Bus Service io Mixed
FiHmy Traffic; Favorable Impacts
Fieevnry Lint Reserved lot Uusus and
Cirpoots, Favorable Impacts
Ramp MilMini ind Bui By Pass Lane;
Favorable Impacts
Rescind Bui/Pool Lin*. Ramp Meter-
in|, and Bin By-Pau Lanes; Modal
Impacts
Round Bui/Pool Lane. Ramp Meter-
ing, and Bus By-Pass Lanes; Favorable
Impacts
Conltaflaw Fittwiy 1 ana Reserved
for Buses; Favorable Impacls
Canliallaw But Lane. Expanded Ex-
press Bus Service, anil Park and Ride
Lou; Favorable Impacts
Conlraflaw Bus Lane. Expanded Ex-
press Bus Service, and Lois; Assum-
ing 70%/30% Directional Split;
Favurable Impacts
Reserved Arterial Median lane lor
Express Buses; Favorable Impacts
CaulrafloM Curk lane loi Lou!
Buses on Pair ol Due Way Anerials;
Favorable Impacts. Unbound
Arterial/Outbound Arterilll
IMPACT ON A.M. PEAK
HOUR CORRIDOR
VEHICLE VOLUME*
BASE PEAK
HOUR
VOLUME
19.661
18.66?
19.667
19.667
19.667
14.760
14.760
13.500
3.760
6.000
PERCENT
CHANCE
-1.47%
-6.30*
-3.06%
-3.07%f
-6.98%
-1.69%
-3.72%
-4.07%
-16.47%
-4.40%
IMPACT ON A.M. PEAK HOUR CO
CONCENTRATIONS IN jig/"'1 AT REFERENCE
RECEPTOR. FROM AFFECTED FACILITY EMISSIONS"
TYPICAL. CO 00
DISPERSION!
BASE VALUE
6.756
6.756
6.756
6.766
6.766
4.791
4.738
4.006
4.964
3.992^-^'
^3,349
CHANCE
-139
-664
-381
«.A.»
-603
4226
*10B
-116
-779
-S32^^
^-^365
TYPICAL. POOR
DISPERSION!
BASE VALUE
1.210
1.210
1.210
8.210
1.210
6.769
6.769
6.741
6.485
4.992^-"'
^--^793
CHANGE
-203
-762
-537
N.A.*
-132
+277
t104
-111
-991
-685^-^'
^-""«474
PRO GRAM COSTS IN
1976 DOLLARS 1x1.000)
CAPITAL
(ONE-TIME.
IMPLEMENT A
TION)"1'
3.16I/4.7I»IW
3.720/6.360
6.224/6.844
4.162/6,412
6.241/7.161
962
3,661/6.281
3.661/S.281
3.S94/4.I34
461
OPERATING'*'
(PER YEAR)
t.447
1.131
1.703
1.761
2.266
641
1.111
1.818
1.130
123
•On all highway lacHilin explicitly included in the analysis of the prototype corridor (see diagrams in Exhibit _!_); in both directions.
Volume is lor Ireeway and/or arterial segments approximately 1 mile out Irom the CBO (adjacent lo the CBD in tin case of Scenario 10).
"CO concentration 60 feel Irom downwind edge ol piimary corridor facility, based on vehicular emissions from affected facilities only;
uninterrupted traffic flow conditions ire lisa assumed. Maximum I hour inragi CO concentrations may be approximated using the procedure la Exhibit 14.
1 See Exhibit.!!_ lor a tabular description ol these meteorological conditions.
I * This value includes the vehicles originally using the conidor lieeway, but estimated as being unable to pass through during peak hour
because ol How breakdown caused by congestion.
fe>CO Concentration impacts lor Scenario 4 could nut be reliably estimated. See Exhibit .15. and text lor further explanation.
U Represents incremental operating costs
[b The two capital cost entries represent the range in costs depending upon whether existing parking
facilities (e.g., shopping center) or newly constructed facilities am required (or park and-ride lots.
-------
corresponding reductions in peak direction freeway vehicle volumes. In
Scenarios 6 and 7, CO concentrations are estimated to increase relative
to the base conditions. The increase in CO concentrations in several con-
traflow reserved freeway lane scenarios reflects the travel and meteoro-
logical conditions assumed in those scenarios. The results do not indicate
that contraflow lanes, per se, have undesirable air quality effects , but
rather illustrate the importance of carefully analyzing the potential air
quality effects of implementing a contraflow lane on freeways carrying
heavy traffic volumes in the "off-peak" direction.
Both the capital and annual operating and maintenance costs of the local-
ized scenarios are sizeable. As discussed in Section III. the costs of pur-
chasing and operating new buses for express bus service represent a sub-
stantial part of the total cost of the scenarios.
Regional Scenarios
Exhibit 9 in Section III of this report and describes the 10 scenarios
selected for analysis of regional HC, NO , and CO emission impacts.
The first two regional scenarios (11 and 12) deal with areawide carpool/
vanpool programs focused on major employers in a prototype medium -
-sized region (500, 000 - 1 million population) and a large region (1 mil-
lion + population), respectively. Scenarios 13 and 14 deal with the
application of a combination freeway corridor strategy (e.g., reserved
lanes, express bus, park and ride lots) for several corridors throughout
the region. Scenarios 15 and 16 do the same for a combination arterial
strategy. The last four strategies involved the combination of both area-
wide carpool/vanpool and freeway corridor strategy components.
The VMT, emission, fuel consumption, and cost impacts of the 10 re-
gional scenarios are summarized in Exhibit B. Reductions in total region-
al VMT in the range of 1. 0 to 1. 9 percent are attributable to Scenarios
11, 12, and 17 through 20 which involve carpool and vanpool programs
focusing on large employers. These reductions correspond to reductions
of 3 to 6. 5 percent in weekday work trip VMT. This represents a sub-
stantial shift of low occupancy auto trips to transit, carpool s, and vanpool s
during peak travel periods, which will reduce congestion and conserve en-
ergy as shown in Exihibit B. These same scenarios are also estimated to
yield the largest reductions in regional HC, NO , and CO emissions.
Scenarios 13 through 17, which involve the implementation of reserved
lanes on multiple radial freeways or arterials in a region, generally re-
sulted in total regional and work trip VMT reductions of less than 0. 5 per-
cent and 1. 5 percent, respectively. The small reductions in VMT are in
VII
-------
EXHIBIT B
SUMMARY OF ESTIMATED IMPACTS FOR THE REGIONAL PROTYTYPE SCENARIOS
PROTOTYPE SCENARIO
ID
No.
11
12
13
14
IS
16
17
11
19
20
BRIEF TITLE'
Carpool/Vanpool Program, Medium
Size City; F avorahle Impacts
Carpool/Vanpool Pfe|rim. Large
City; Favorable Impacts
Reserved Bui/Pool Line, Ramp
Metering, ind Bin By Past lines on
Ad Appropriate Freeways; Modesl
Impacts
Reserved Bus/Pool Lines, Ramp
Metering, and Bin By-Pass Lanes on
All Appropriate Freeways; Favorable
Impacts
Reserved Median Lane lor Express
Buses on Appropriate Radial Ar
lerials; Modesl Impacts
Reserved Median Lane lor Express
Buses in Appropriate Radial Ar
terials; Favorable Impacts
Carpool/Vanpool Program and Flee-
way Reserved Lanes; Modesl Impacts
Carpool/Vanpool Program and Free-
way Reserved Lanes: Favorable
Impacts
Cerpool/Vanpool Program. Reserved
Lanes. Ramp Metering, and Bus By
Pass Lanes; Modest Impacts
Carpool/Vanpool Program. Reserved
Lines. Ramp Metering, and Bus By-
Pass Lanes; Favorable Impacts
CHANGE IN REGIONAL
WEEKDAY VMT
AS PERCENT
OF TOTAL
VMT
-I.5V.
-1.5%
-825%
-0.44%
-0.23%
-0.31%
-10%
-I.9X
-10%
-19%
AS PERCENT
OF WORK
TRIP VMT
-5.0%
-5 OS
-0.8%
-1.5%
-O.B%
-1.3X
-33%
-6.3%
-33%
-85%
CHANGE IN REGIONAL WEEKDAV
HIGHWAY EMISSIONS IN TONS!
IIC
-!.«•
-1.3
-0.3
-2.5
<2.1
-0.7
-2.4
-105
- 4.S
-10.9
NOX
-0.6*
-2.»
-0.5
-0.4
-0.4
-06
-1.9
-3.3
-1.8
-3.3
CO
-15.0'
-83.4
t 26
-1J.9
4 37.2
' 5.1
-29.1
-11.1
-29.0
-83.S
CHANGE IN
ANNUAL
FUEL
CONSUMPTION
IN MILLIONS
OF GALLONS
-2.6'
-11.6
- 1.5
-2.7
-1.8
-2.9
- 7.2
-14.1
- 7.3
-14.2
PROGRAM COSTS IN 1976
DOLLARS Ixl.OOOl
CAPITAL
(ONETIME.
IMPLEMENTA
TION)
-
14.566/19.446
18.744/23.604
18.868/21.704
18.868/21.704
9.604/14.664
11.190/18.050
14.586/19,446
18.744/23.604
INCREMENTAL
OPERATING
( PER YEAR)
76
404
5,253
6.798
5.984
5.984
6.408
5.921
5.957
7,202
•AH scenarios except 1I\\ are lor a "large" city (1.000,000 < SMSA population). Scenario 11 Is set In a "medium size" city (600.000 1,000.000 SMSA population).
I Estimated at 75"F assuming iMintirnipUd traffic Haw candltiani.
-------
large part related to the limited size of the peak period radially-oriented
CBD travel market in most large urban areas. For example, home to work
trips and VMT comprise approximately 20 percent and 30 percent of total
weekday regional person trips and VMT, respectively. Travel survey data
suggest that approximately 15 percent of home to work person trips are
oriented to the CBD of large urban areas.
Scenarios 11 and 12, which involve major employer carpool and van-
pool programs, are particularly cost-effective in reducing regional air pol-
lution emissions.
Scenarios 13 through 17, which incorporate express bus service and re-
served freeway or arterial lanes in multiple corridors, are less cost-effec-
tive than Scenario 12 in reducing HC emissions. The combination of carpool
and vanpool programs with express bus service/reserved lane strategies in
Scenarios 18 and 20 are estimated to result in larger reductions in HC emis-
sions than Scenario 12 but for a significantly larger cost.
Considerations in Air Quality Analyses
The report illustrates the magnitude and type of air quality, emission,
travel, fuel consumption, and cost impacts that could result from the imple-
mentation of selected TSM actions in settings similar to those described for
the 10 localized and 10 regional scenarios. The reader should note that
the impact estimates developed in the project are scenario-specific and
great care must be taken in attempting to directly apply the results of this
analysis to specific real-world circumstances.
The impacts presented in this report also reflect assumed "modest"
and "favorable" travel impacts based on the findings of the literature re-
view. The travel impact estimates are considered to be reasonable, par-
ticularly in light of the wide range in travel impacts which have been ob-
served in demonstration projects. However, substantially different travel
impacts could occur in a specific application, depending upon the charac-
teristics of the project.
The application of TSM tactics such as pricing incentives/disincentives,
auto restricted zones, area licensing, and parking pricing and supply con-
trols in conjunction with the reserved lane, carpool, vanpool and related sce-
nario tactics has not been examined in this report. Such tactics combined
with those examined in this report offer considerable promise for achieving
even more significant reductions in emissions.
IX
-------
Selection of TSM Actions for Analysis
The analysis of the prototype localized and regional scenarios demon-
strates the need to clearly define the geographic scale of the air quality
problems facing an urban area. The selection of tactics for analysis should
be consistent with the scale of the area's air quality problems. Many tac-
tics are particularly applicable to alleviating localized air quality problems
while other tactics, such as carpool and vanpool programs, are appropriate
for addressing regional air quality problems.
For example, the results of the regional scenarios illustrate that the
application of the HOV freeway or arterial lanes on multiple radial highways
was substantially less effective in reducing regional air pollution emissions
than the carpool/vanpool programs. However, these same strategies were
considerably more effective in reducing CO concentrations adjacent to appli-
cable freeways and arterials.
-------
TABLE OF CONTENTS
Section
Page
II
III
IV
EXECUTIVE SUMMARY i
INTRODUCTION I.I
Objective 1-1
Background 1.2
Analysis Approach 1.5
PERFORMANCE AND POTENTIAL OF RESERVED
LANE, CARPOOLING/VANPOOLING, AND TRANSIT
SERVICE PROGRAMS II. 1
Literature Review Findings--TSM Strategy Impacts
and Potential II -1
Transportation Programs Recommended for Detailed
Scenario Analysis II.5
TRAVEL, AIR QUALITY, AND RELATED IMPACTS
OF SELECTED TRANSPORTATION PROGRAMS III.l
Prototype Scenarios Selected for Detailed Analysis III. 1
Localized Scenario Impact Estimates III.9
Regional Scenario Impact Estimates III.26
SUMMARY AND ASSESSMENT OF SCENARIOS IV. 1
Localized Scenarios IV. 1
Regional Scenarios IV.6
Guidelines for Air Quality Analyses IV.9
Appendix
A
B
Analytical Assumptions and Methodology for Non-Cost
Impact Estimates A.I
Unit Cost Assumptions B.I
XI
-------
LIST OF EXHIBITS
Exhibit
1 Illustrative Transportation-Related Air Pollution Problems 1.3
2 Generalized Analysis and Evaluation Framework 1.6
3 Freeway Priority Treatment for High Occupancy Vehicles II.3
4 Arterial Priority Treatment for High Occupancy Vehicles II.6
5 Area-Wide Carpool and Vanpool Programs 11.10
6 Transit Fare Reductions and Service Improvements 11.13
7 Localized Scenarios Selected for Detailed Analysis III.3
8 Illustrative Diagrams of Affected Prototype Highway Facili-
ties III-5
9 Regional Scenarios Selected for Detailed Analysis III.7
10 Major Travel Impacts for Localized Scenarios III. 11
11 Illustrating the Impact of Prevailing Meteorological Condi-
tions on A.M. Peak Hour Concentrations III. 14
12 Illustrating the Spatial Variation in A.M. Peak Hour CO
Concentration Around Prototype Highway Facilities III. 16
13 Localized CO Concentration Impacts: Comparison of Sce-
narios Involving 8 Lane Freeway III. 17
14 Relationship Between Maximum 8-Hour and Peak 1-Hour
CO Concentrations for Typical, Poor Dispersion Con-
ditions III. 19
15 Localized CO Concentration Impacts: Comparison of Sce-
narios Involving Contraflow Lane on 6 Lane Freeway III.21
16 Localized CO Concentration Impacts: Comparison of Sce-
narios Involving Radial Arterials as the Primary Facility III.22
17 Capital and Annual Operating and Maintenance Costs for
Localized Scenarios III.24
18 Major Travel Impacts for Regional Scenarios III.28
19 Illustrating the Effects of Temperature on Regional Emis-
sions III. 30
20 Comparison of Estimated Regional Impacts of a Carpool/
Vanpool Program Implemented in Two Prototype Regions III.31
21 Estimated Impacts for Nine Regional Scenarios in a Large
Urban Area: Regional Hydrocarbon Emissions III.32
22 Estimated Impacts for Nine Regional Scenarios in a Large
Urban Area: Regional Nitrogen Oxides Emissions III.33
23 Estimated Impacts for Nine Regional Scenarios in a Large
Urban Area: Regional Carbon Monoxide Emissions III.34
24 Estimated Impacts for Nine Regional Scenarios in a Large
Urban Area: Regional Highway Fuel Consumption III.36
Xll
-------
LIST OF EXHIBITS (Continued)
Exhibit Page
25 Capital and Annual Operating and Maintenance Costs for
Regional Scenarios III.38
26 Summary of Estimated Impacts for the Localized Prototype
Scenarios
27 Comparison of Localized Scenarios on Cost and CO Con-
centration Impacts IV. 4
28 Summary of Estimated Impa" s for t e Regional Prototype
Scenarios IV. 7
29 Comparison of Regional Scenarios on Cost and Regional
Emissions Impacts IV.8
Xlll
-------
I. INTRODUCTION
OBJECTIVE
This report evaluates the use and cost-effectiveness of alternative short-
range reserved lane, transit, carpool, and vanpool programs as techniques
for improving air quality in urban areas. The report has been prepared in
accordance with Section 108(f) of the Clean Air Act, as amended August 1977.
It is intended to assist elected officials, government administrators, trans-
portation planners, and transportation system operators in developing trans-
portation measures for the State Implementation Plan and integrating trans-
portation system management (TSM) and air quality planning programs as
required by the Federal Highway Administration, the Urban Mass Transpor-
tation Administration and the Environmental Protection Agency, respectively.112
The specific types of short-range transportation programs examined in
this report include:
. priority treatment for high occupancy vehicles on freeways and
arterials;
. areawide carpool and vanpool programs; and
. transit fare reductions and service improvements.
The application of other transportation measures such as inspection and
maintenance programs for vehicles, parking controls, traffic operations,
and pricing are not covered in this project, but will be the subject of future
study.3
JFederal Highway Administration and Urban Mass Transportation Administra-
tion, Transportation Improvement Program. Part 450; Federal Register:
Vol. 40, No. 181, September 17, 1975.
Environmental Protection Agency. Transportation Planning Guidelines.
Draft Guidelines, November 28, 1977.
3Section 108(f) of the Clean Air Act, as amended August 1977 requires EPA
to publish information reports regarding processes, procedures, and meth-
ods to reduce or control each transportation related pollutant. Reports will
be prepared on a wide range of actions (e. g., traffic flow improvements,
on-street parking controls, road user charges, and road use restrictions).
I.I
-------
The report is intended to provide information to assist urban areas cov-
ered by EPA's Transportation Planning Guidelines in:
o assessing the applicability and potential of the three classes of
programs described above for improving localized and regional
air quality;
. estimating and evaluating the cost-effectiveness of such pro-
grams and their related travel, energy consumption, cost,
and economic impacts; and
. identifying key factors (e.g., meteorological conditions, vehicle
type distributions, and vehicle operating speeds) likely to affect
air quality and air pollution emissions.
This information report addresses the above issues at a sketch planning scale
of analysis. More detailed transportation and air quality analyses will be
required to adequately address localized and regional air quality problems
within specific urban areas.
BACKGROUND
Problem
Virtually all urban areas of more than 200,000 population in the nation
currently do not meet National Ambient Air Quality Standards (NAAQS) for
photochemical oxidants (Ox). Many of these areas also exceed National Am-
bient Air Quality Standards for carbon monoxide (CO). Vehicluar travel
within these urban areas is a major source of both pollutants.
As illustrated in Exhibit 1, transportation-related air quality problems
are of two general types: localized and regional.
Localized transportation-related air quality problems generally result in
CO concentrations exceeding either the one hour or more likely, the eight
hour CO air quality standard. Factors contributing to this problem include
high vehicular traffic volumes occurring under congested traffic conditions
frequently found in densely developed portions of urban areas.
Regional transportation-related air quality problems are typically a re-
sult of vehicular and stationary source hydrocarbon (HC) and nitrogen oxide
(NOX) emissions chemically reacting in the atmosphere to produce oxidant
1.2
-------
EXHIBIT 1
ILLUSTRATIVE TRANSPORTATION-RELATED AIR POLLUTION PROBLEMS
TYPE OF
PROBLEM
LOCALIZED
REGIONAL
POLLUTANT
CARBON MONOXIDE
PHOTOCHEMICAL
OXIDANT
AIR QUALITY
STANDARD
8 HOUR
1 0,000 Mgm/mettr3
(9 PPM)
1HOUR
40,000 yugm/meter4
(35 PPM)
1HOUR
IGOyugm/meter
(0.08 PPM)
TYPICAL IMPACT
AREA
• INTERSECTIONS
• LOCATIONS ADJACENT
TO FREEWAYS
AND ARTERIALS
OVERALL URBAN AREA
(BASED ON OXIDANT
CONCENTRATIONS
MEASURED AT
SPECIFIC LOCATIONS)
SELECTED TRAVEL FACTORS
CONTRIBUTING TO PROBLEM
• HIGH VEHICULAR
TRAFFIC VOLUMES
• STOP AND GO TRAFFIC
FLOWS (e.g. IDLING)
• HIGH VEHICULAR
TRAFFIC VOLUMES
• HIGH SPEEDS
j/STANDARD NOT TO BE EXCEEDED MORE THAN ONCE PER YEAR.
1.3
-------
pollutants. The chemical reactions producing oxidants are complex and de-
pend upon many factors such as prevailing meteorological conditions and the
topographic, land use, and industrial characteristics of an urban area.
The distinction between the CO and oxidant pollutants is important in that
different TSM actions are generally required to effectively address localized
as opposed to regional air quality problems. For example, a TSM program
to implement a reserved lane for carpools and buses on a single freeway may
reduce CO emissions in the vicinity of the freeway, but is unlikely to have a
noticeable impact on regional oxidant emissions. Similarly, a regional car-
pool program may contribute to a reduction in hydrocarbon and nitrogen oxide
emissions (and, indirectly, oxidant concentrations), but generally is unlikely
to have any measurable impact on localized CO concentrations.
Legislative Requirements
With the passage of the Clean Air Act of 1970, a comprehensive national
program was undertaken to improve air quality, particularly in urban areas.
EPA promulgated air quality standards and undertook programs (1) to reduce
vehicle-related air pollutants through vehicle emission standards, emission
controls (e.g., retrofits), and inspection/maintenance programs, and (2) to
implement transportation policies, regulations, and projects to further re-
duce transportation-related emissions to meet air quality standards.
In accordance with the Clean Air Act of 1970, transportation control plans
were developed by state, regional, and local agencies as well as by EPA for
those urban areas which did not meet air quality standards. Unfortunately^
the transportation control plans were frequently developed on an ad-hoc basis
under very restricted time schedules, and did not have clearly defined agency
responsibilities and/or funding sources for ultimate implementation of actions
in the control plan. Consequently, the control plans generally had limited ef-
fect on improving air quality in applicable urban areas.
Several important legislative and procedural developments have occurred
since 1975 which are intended to remedy many of the important limitations of
the initial transportation control plans.
In September 1975, the Federal Highway Administration (FHWA) and the
Urban Mass Transporjation Administration (UMTA) jointly issued regulations
requiring that urban areas (through a designated metropolitan planning orga-
nization - MPO) develop both short-range and long-range transportation plans
to improve the transportation systems within urban areas.
1.4
-------
The short-range plan is referred to as the Transportation System Man-
agement Element (TSME). The TSME is intended to identify low-cost, short-
range transportation improvements, services, and programs which can be
implemented within a five-year period. Projects must be included in the
TSME in order to qualify for U.S. DOT funding. An important aspect is
that the planning program must be coordinated with air quality planning with-
in the urban area and must consider the air quality impacts of proposed
transportation actions. Similarly, the long-range element is to account for
the air quality effects of long-range transportation improvements.
The Clean Air Act, as amended August 1977 include the following major
provisions for reducing travel-related emissions and meeting air quality
standards in urban areas:
. States must prepare State Implementation Plans (SIP) by
January 1, 1979. The SIP are to contain transportation
plans for CO and oxidant nonattainment urban areas. The
plans are to achieve CO and oxidant standards as expeditiously
practicable, but no later than 1982 unless the implementation
of all reasonable measures will not attain the NAAQS.
Under such circumstance, an extension to 1987 may be granted.
. $75 million is authorized (to be appropriated) by the Act to
develop plans for nonattainment areas. This authorization
is to support transportation-related planning activities.
. Transportation planning guidelines are being issued by EPA
to promote agency interaction at all levels of government,
involvement of local elected officials, effective public parti-
cipation, and integration with the ongoing US DOT planning
processes. The guidelines provide for annual EPA review
and approval of the transportation planning process and
progress in meeting air quality standards.
. In the SIP, short-range and medium-range analyses of air
quality in nonattainment areas are to be conducted for 1982
and 1987, respectively. The analyses are to consider alter-
native transportation measures to improve air quality and
reduce transportation-related emissions.
ANALYSIS APPROACH
Exhibit 2 illustrates the overall analysis and evaluation process used in
the project. Each major phase of the process is summarized below.
1.5
-------
EXHIBIT 2
GENERALIZED ANALYSIS AND EVALUATION FRAMEWORK
PROGRAMS
OF INTEREST:
• RESERVED HOV LANE
• CARPOOL/VANPOOL
•TRANSIT FARE AND
SERVICE IMPROVEMENTS
CONDUCT LITERATURE
REVIEW OF
PROGRAMS
IDENTIFY "PROMISING"
PROGRAMS FOR IMPROVING
AIR QUALITY
DEFINE PROTOTYPE
SCENARIOS FOR
ANALYSIS. IN TERMS OF:
t ACTIONS OR
PROGRAM BEING
IMPLEMENTED
•PROTOTYPE REGION
OF HIGHWAY
CORRIDOR
ESTIMATE IMPACTS OF
ALTERNATIVE SCENARIOS
•TRAVEL
•AIR QUALITY/ EMISSIONS
•ENERGY CONSUMPTION
•ECONOMIC
•COSTS
EVALUATE COST
EFFECTIVENESS OF
SCENARIOS
-------
Literature Review
A comprehensive literature review was conducted to identify and summa-
rize the travel, air quality, cost and related impacts of the freeway and ar-
terial priority treatment programs, areawide carpool and vanpool programs,
and transit fare reduction and service improvements programs. The litera-
ture review included relevant demonstration and operational projects and
analytical/model-based evaluations of the programs of interest. The findings
of the review were used (1) to identify those transportation programs having
the potential to improve localized and/or regional air quality; and (2) to pro-
vide the basic inputs for estimating the travel, air quality/emission, cost and
related impacts of the 20 transportation programs selected for analysis and
evaluation in this project.
The findings of the literature review are presented in Section II. An an-
notated bibliography documenting references examined in the project was pre-
pared for distribution as part of the project.1
"Promising" Transportation Programs
Transportation programs within the scope of this project which demonst-
rated potential for cost-effectively improving either localized or regional air
quality were selected for detailed analysis and evaluation based on the findings
of the literature assessment.
In order to quantitatively assess the air quality and related impacts of in-
terest, 20 scenarios were developed to evaluate the "promising" transportation
measures. A prototype scenario includes the definition of the following:
. the program (individual action or combination of actions)
to be analyzed;
. the physical and operating characteristics of the program
(e.g., number of lanes, hours of operation);
. the geographic area in which the program is to be implemented
(e.g., radial corridor, areawide); and
. "existing" travel and meteorological characteristics for the
geographic area of interest.
Peat, Marwick, Mitchell & Co., Transit Improvement, Preferential Lane
and Carpool Programs; An Annotated Bibliography of Demonstration and
Analytical Experience (Prepared for EPA, Office of Transportation and Land
Use Policy), November 1977.
1.7
-------
The scenarios were defined to represent "real-world" circumstances in
which the alternative programs of interest are typically implemented. The
use of scenarios, rather than actual projects which have been implemented,
provides a more consistent basis for comparing the cost-effectiveness and
the magnitudes and characteristics of the associated impacts for the pro-
grams of interest.
Scenarios were formulated to analyze alternative programs to improve
both localized and regional air quality. The transportation programs receiv-
ing detailed analysis and evaluation are summarized in Section III.
Scenario Impacts
A variety of data sources and analysis procedures were used to estimate
the travel, emission, air quality, energy consumption, economic and cost im-
pacts for the programs and settings (i.e. , scenarios) analyzed. Travel im-
pacts for each scenario were estimated based on the findings of the literature
review, supplemented as required by assumptions of the project team. Tra-
ditional urban transportation planning models were not used in the analysis
because of the difficulty of representing the programs of interest using such
procedures and because of the coarseness of the outputs of such models in
analyzing strategies for reducing localized CO concentrations.
Emphasis was placed on developing "reasonable" travel impact estimates
for each prototype based primarily on before-and-after travel impact data
found in the literature. This approach is consistent with the substantial range
of observed travel impacts associated with similar transportation programs
implemented throughout the nation.
A modified version of the EPA HIWAY Model and the current EPA mobile
source emission factors were used to estimate CO concentrations for localized
programs and tons of emissions by pollutant for regional programs, respec-
tively.' The energy consumption, economic, and capital and operating cost
impacts for each prototype were estimated using published consumption rates,
unit costs, and other applicable data compiled in the literature review.
Environmental Protection Agency, User's Guide For HIWAY, A Highway Air
Pollution Model. EPA-650/4-74-008, February 1975.
2
Environmental Protection Agency, Mobile Source Emission Factors. January
1978.
1.8
-------
A summary of the major data sources, analytical assumptions, and pro-
cedures used to estimate non-cost impacts for each prototype scenario is pre-
sented in Appendix A. Section III summarizes the travel, air quality/emis-
sion, energy consumption, economic, and cost impacts for each scenario.
Evaluation of Scenario Impacts
Section IV evaluates the impacts of promising transportation programs
within the context of 20 prototype scenarios. The section analyzes the cost-
effectiveness of the alternative programs in promoting improved air quality
and reducing vehicular emissions in urban areas. The relative magnitude and
characteristics of the impacts for the localized and regional programs are
compared. An important element of this section is a discussion of factors,
such as prevailing meteorological conditions, stationary source emissions,
and future automobile emission rates, which may affect the transferability
of the project's findings to specific urban areas.
1.9
-------
II. PERFORMANCE AND POTENTIAL OF RESERVED LANE,
CARPOOLING/VANPOOLING, AND TRANSIT SERVICE PROGRAMS
This section summarizes the travel and cost impacts of the following
programs of interest:
. freeway priority treatment for high occupancy vehicles;
. arterial priority treatment for high occupancy vehicles;
. areawide carpool and vanpool programs; and
. transit fare reductions and service improvement programs.
The findings presented in this section are based on a comprehensive lit-
erature review of both operational and proposed programs of the above types,
Based on these findings, programs which have the potential for cost-
effectively reducing emissions and improving air quality were selected.
LITERATURE REVIEW FINDINGS--TSM STRATEGY
IMPACTS AND POTENTIAL
Tabular Summary of Findings
Exhibits 3 through 6 present the travel impacts and capital and operat-
ing costs for the four types of programs noted above. For each of the pro-
grams of interest, strategies of similar physical or operating characteris-
tics are grouped together to illustrate the variability in travel impacts and
costs, and to summarize the voluminous findings of the literature review at
a level of detail that facilitates selection of individual programs and com-
binations of programs for detailed analysis and evaluation in this project.
The format of Exhibits 3 through 6 varies to accommodate the differ-
ences in the descriptive characteristics and travel impacts most relevant
to each program.
In using the tables of Exhibits 3 through 6, the following should be kept
in mind:
II. 1
-------
. In a number of cases, the data or information presented in
various rows of a column may vary in format and/or content.
Unfortunately, this is unavoidable because of the diversity
of information reported in the available sources and the lack
of uniform documentation in the literature.
. Blanks in the table identify data which were either not pro-
vided by available sources or which were considered to be
too ambiguous or unreliable to be usefully reported. Through
these blanks and the "level of documentation" ratings dis-
cussed in the footnote to the tables, the summary tables
graphically highlight the data deficiencies.
. In a number of cases, information for a strategy supported
by data from several sources will be attributed explicitly to
a single source. This alerts the reader to data which are
based on only one experience or model estimate, and which
may not be representative of all the experiences cited for
the strategy.
Freeway Priority Treatment for High Occupancy Vehicles
Documentation of Past Experience
Relative to the other major categories of strategy, experiences with pri-
ority treatment of high occupancy vehicles on freeways were fairly well
documented (see Exhibit 3). The considerable interest and investment in
these strategies and programs prompted substantial demonstration moni-
toring and evaluation efforts in many cases. This was particularly true of
the projects involving the expenditure of large sums in the construction of
new priority facilities, such as the Shirley Highway high occupancy vehicle
lanes.1 However, even for the relatively well documented freeway priority
strategies, the extent, reliability, and transferability of the available infor-
mation are not entirely satisfactory. The primary reasons for this are that
such programs are long-range, capital intensive projects techni-
cally outside the scope of this report, they were included in the literature
review and summary tables because of their similarity to within-scope re-
served lane approaches and because of the wealth of potentially transferable
data available. However, in evaluating these data, one must be careful to
account for the significant differences between reservation of existing lanes
and the construction of separate new priority facilities.
II. 2
-------
FREEWAY PRIORITY TREATMENT FOR
HIGH OCCUPANCY VEHICLES
SttlnKuOiUMCTlrtln"
IL3
-------
characteristics of specific demonstration projects varied significantly and
the data reported were frequently incomplete, ambiguous, or reported in a
form that made comparison difficult. Finally, data were primarily available
for larger urban areas, so the impacts of these programs on smaller areas
is uncertain.
Assessment of Strategy Impacts and Potential
Freeway priority strategies can have significant localized (CO) air
quality impacts and reduce vehicle volumes in the peak period by 3 to 10
percent. Freeway priority strategies are especially effective when applied
as part of strategies favoring high occupancy vehicles in a corridor and dis-
couraging the use of automobiles through disincentives (e.g., parking
charges and restraints, etc.). Other factors which can promote the effective-
ness of such strategies include a soundly designed enforcement program,
improved transit service and marketing programs, and a public information
program to inform affected travelers of the benefits and costs of reserving
an existing freeway lane for HOV's.
When these strategies are implemented to improve localized CO air qual-
ity, great care in planning and implementation is necessary. Diversions to
and from parallel roads and the possibility of creating counterproductive in-
creases in congestion on non-priority lanes must be considered in designing
these strategies. Even when the travel time for high occupancy vehicles is
reduced substantially by the strategy, regional air quality and VMT impacts
of freeway priority strategies are not very significant. The reasons for
this are:
. CBD oriented peak work travel, that travel primarily suscep-
tible to these strategies, is only a fraction of total travel; and
. despite the travel time reduction, overall door-to-door travel
time may still be shorter by single occupant car than by either
bus or carpool.
As with any of the strategies, the freeway priority strategies can make a
useful contribution to regional air quality as part of a comprehensive pack-
age of strategies whose total impact is significant.
Among the freeway strategies treated in the strategy summary tables,
the following seem to have the greatest potential in terms of travel impact:
. with-flow'freeway lanes reserved for buses and carpools;
. contraflow bus-only lanes on freeways; and
II.5
-------
. metered freeway access ramps with bus by-pass lanes.
Arterial Priority Treatment for High Occupancy Vehicles
Documentation of Past Experience
In most cases, the available documentation for strategies involving the
priority treatment of high occupancy vehicles on arterials was unsatisfactory
(see Exhibit 4) for the same reasons as cited for the freeway priority strate-
gies. Adequate before-and-after data for critical travel variables were un-
available. Project monitoring was frequently qualitative and project evalu-
ation activities, when present at all, were not focused on overall travel and
air quality improvement impacts. Finally, transit ridership data are not
usually available on a basis which would permit link-specific evaluation of
projects confined to specific urban arterial segments.
Assessment of Strategy Impacts and Potential
For the reasons cited above, it is difficult to make reliable quantitative
assessments of the travel and air quality impact performance of the spe-
cific priority arterial strategies. Generally though, arterial strategies
have potential for improving localized CO air quality, especially in congested
downtown areas which are more directly served by arterials than by freeways,
Overall, the potential which arterial strategies offer for improving local-
ized CO air quality seems to be less than the,potential offered by freeway
strategies for the following reasons:
. the amount of travel affected by arterial strategies tends to be
smaller on a project-by-project basis--although this is partially
offset by the greater number of arterial streets on which improve-
ments might be made;
. traffic signal and other delays encountered on arterials (but
not freeways) tend to dilute the travel time savings achieved
by preferential treatment of high occupancy vehicles;
. turning vehicles may traverse the priority lane—thereby
inhibiting its effectiveness;
. lane restrictions on arterials are more difficult to enforce, also
tending to dilute the travel time advantages for high occupancy
vehicles; and
II.6
-------
EXHIBIT 4
ARTERIAL PRIORITY TREATMENT FOR
HIGH OCCUPANCY VEHICLES
SE CONDITIONS *ND IRAVEL IMPAi
as?
-------
EXHIBIT 4 (Continued)
: j:
t „
u
"
Knsrr
-------
. since there are frequently good substitute routes for affected
arterials (which tends to be less true for freeways), travel
diversions may limit arterial strategy effectiveness.
Strategies which provide reserved median lanes for express buses over
substantial uninterrupted distances on major arterials appear to have poten-
tial for reducing transit travel times and diverting trips to transit, which,
in turn, would have an impact on air quality. This is particularly true if
preferential signal treatment and park-and-ride facilities are also provided.
Such strategies are relatively costly to implement and may involve traffic
safety problems, at least in the short run (as illustrated by the demonstration
project experience with a median bus lane on 7th Avenue in Miami).
Although the available data do not permit a conclusive assessment, strat-
egies employing contraflow bus lanes on major arterials (especially one-way
couplets) may induce increases in transit ridership at relatively low cost.
Care should be taken, however, that vehicle volumes, transit potential, and
peak traffic directionality conditions are favorable for the reservation of a
contraflow lane. Safety is and should be a major consideration in implemen-
ting such a facility. The available information suggests that with-flow curb
bus lane strategies have minimal impacts in practice and that reserved lanes
for carpools on arterials are impractical.
Although not included in this study, there are a number of arterial- and
CBD-oriented strategies which substantially augment the tools considered
in this study for improving downtown air quality. Auto free zones, pedes-
trian and transit malls, and various parking fee and parking restraint pro-
grams are among the types of strategies which might be combined with the
strategies considered in this study to improve downtown air quality.
Areawide Carpool and Vanpool Programs
Documentation of Past Experience
Moderately good documentation is available on areawide carpool and van-
pool strategies from both demonstration and model estimate sources (see
Exhibit 5). However, in interpreting the reported results, several points
should be considered:
. results are frequently available only for program participants,
making it difficult to obtain a percentage impact value reflective
of total regional travel;
ll.ll
-------
. ride-sharing programs and the reported results almost always
focus on work trip travel, which is only a portion of total travel;
. reported "after" results for ride-sharing programs frequently
focus on the near term responses among the best organized pro-
grams--participation rates may decline over time as program
enthusiasm wears off and ride-sharing relationships run into
difficulties; and
. the results of actual ride-sharing demonstrations and model
estimates are difficult to compare or combine because the im-
pact results tend to be reported in different forms for each and
the model estimates are usually based on impact assumptions
and time/cost simulation equivalences which may not be entirely
compatible with the demonstration experiences.
Assessment of Strategy Impacts and Potential
Well-organized areawide carpool matching programs focusing on major
employers can have a positive impact on regional air quality and reduce
work trip VMT by 1 to 5 percent. Generally, employer-focused programs
are more effective than decentralized, areawide programs. The major
reason for this is that the reluctance to provide personal information con-
nected with the matching program and to ride with strangers tends to be
reduced when employers are actively involved in the program. With some
rare exceptions, it is unlikely that areawide ride-sharing programs will have
significant localized air quality impacts.
Vanpooling programs have also experienced success in certain cases
for large employers. Vanpooling programs should be incorporated into an
overall, integrated regional ride-sharing program. Since vanpooling is prac-
tical for large employers whose employees tend to commute more than 15
miles (one-way) to work, and since vanpooling and carpooling may be com-
petitive, it would not be advisable to evaluate the regional air quality impacts
of vanpooling as an isolated strategy.
Ride-sharing programs tend to be most effective when they are not
competitive with mass transit. Thus, programs should focus on employers
which are not located in downtown areas or areas not well-served by transit.
The air quality impacts of both carpool matching and vanpool programs
can be significantly improved by incorporating ride-sharing incentive and
single occupancy auto disincentive strategies into the overall program.
Such strategies would include preferential parking for pool vehicles, lower
II. 12
-------
EXHIBIT 5
AREA WIDE CARPOOL AND VANPOOL PROGRAMS
l»g>IIIHI>ni|[BMTW
tatr^t
11.13
-------
rate or free parking for pool vehicles, and special employer incentives for
employee pool members. "While many of these strategies are themselves
beyond the scope of this study, they are noted to emphasize the importance
of an integrated metropolitan area transportation control plan incorporating
both regional and local elements.
Overall, well planned and implemented carpool matching and vanpool
programs are likely to be cost-effective. The challenge faced by these or-
ganized ride-sharing programs is to surmount the barriers resulting from
variable working hours, on-the-job auto requirements, home or work lo-
cation, and strong travel preference for driving alone.
Transit Fare Reductions and Service Improvements
Transit improvement strategies are an essential element of any com-
prehensive program to improve air quality by providing low-occupancy ve-
hicle disincentives and high-occupancy vehicle incentives. These programs
can only be effective if an attractive alternative is provided which does not
involve a severe loss of mobility or travel amenities. Some of the many tran-
sit improvement strategies which may be included in such an incentive/disin-
centive package are: reducing transit fares; improving transit facilities
(shelters, etc.); improving security arrangements; expanding bus services,
especially express bus services; marketing programs; fare collection meth-
ods (use of discount passes, tokens); and providing paratransit services.
In addition to serving as a necessary element of comprehensive trans-
portation programs, public transit improvements promote air pollution
and VMT reductions. Fare reductions and service initiation or expansion
focused on radial express bus service could have a significant impact on
localized CO problems in major commuting corridors, especially when
combined with strategies giving priority freeway or arterial treatment.
Expanded radial express bus service can be a cost-effective approach
for achieving air quality improvements. Substantial regional fare reductions
and service improvements can generate substantial transit ridership in-
creases--up to 25 percent or more, but these programs can be costly.
The relatively low cost-effectiveness ranking of these approaches is the
result of the price inelasticity of transit ridership (typically an elasticity
in the neighborhood of -0. 3) and the difficulty of translating any marginal
increase in transit service into a perceived improvement in service for
a significant number of potential users.
-------
When estimating the effectiveness of such strategies for improving
air quality, the following factors should be considered:
. the greatest percentage gains tend to be in areas where the
base transit share is relatively small;
. VMT and associated emission reductions may be offset
to some extent by the alternate use of automobiles left
home by commuters;
. in most areas, transit can effectively serve only a
limited number of origins and destinations;
. ridership gains usually contain a large percentage of trips
which were induced, previously made by walking, or pre-
viously made as an auto passenger;
. ridership gains are often greatest in off-peak rather than
peak periods, reducing the localized air quality improve-
ment potential of such gains; and
. air pollution reductions resulting from transit ridership
gains are partially offset by additional bus emissions
associated with the service increases.
Transit strategies focused on intra-CBD travel for large urban regions
might attract significant ridership. However, the air quality improvements
achieved by such strategies are likely to be limited because:
. the majority of ridership increases are associated with
induced travel and tripmakers who formerly walked or
were auto passengers;
. a very large portion of such ridership increases are
during off-peak travel periods; and
. improved service levels must be carefully balanced against
bus utilization for reasons of cost and net air quality impact.
Other CBD strategies not considered in this report (e.g., auto free zones,
area licensing, transit malls, and parking management) may be capable of
achieving a greater reduction in CBD CO concentrations.
II. 16
-------
TRANS1TFAKI, lir.DUCTlONS AND
SCftVICK IMPROVEMENTS
-------
TRANSPORTATION PROGRAMS RECOMMENDED FOR
DETAILED SCENARIO ANALYSIS
The strategies considered in this report have the potential for achieving
improvements in regional air quality--especially when combinations of
strategies which include strong incentives and disincentives (e.g., auto
restricted zones, pricing) not within the scope of this report are included in
the total transportation control plan. On the basis of the literature review
and analysis of demonstration projects, the strategies which appear to
have the greatest potential for achieving improvements in localized CO air
quality in a cost-effective manner include:
. With-flow freeway lanes reserved for buses and carpools;
. Contraflow bus lanes on freeways;
. Metered freeway access ramps with bus by-pass lanes;
. Contraflow bus lanes on major one-way arterial pairs;
. Provision of high level express bus service with reduced
fares, operating in mixed traffic on major arterials or
freeways;
. Provision of high level express bus service (possibly with
reduced fares), combined with a reserved lane for buses
and carpools on the appropriate freeway facility; and
. Provision of high level express bus service (possibly with
reduced fares), combined with a reserved median lane for
buses and bus preemption of traffic signals on an appropri-
ate arterial.
For regional air quality impacts, it is suggested that emphasis be
placed on the analysis of integrated areawide ride-sharing programs
directed at large employers and including carpool matching, vanpool
formation assistance, and promotional components. It would also be
advisable to analyze the regional impacts of an areawide program to
apply one or more of the above listed "localized" strategies to all
appropriate facilities in the region.
11.19
-------
It is emphasized that the contribution which transportation strategies
such as the above can make to improving both regional and localized
air quality can be significantly enhanced by developing a total, integrated
regional and localized program for achieving air quality. Such a pro-
gram would incorporate strategies such as those listed above as well as
strategies which are beyond the scope of this report.
11.20
-------
HI. TRAVEL, AIR QUALITY, AND RELATED IMPACTS
OF SELECTED TRANSPORTATION PROGRAMS
This section presents and assesses the results of the 20 prototype sce-
nario analyses. These prototype scenarios were designed to provide rep-
resentative findings on the range of travel, air quality /emission, fuel con-
sumption, cost, and economic impacts of TSM programs which appear to
have potential for localized or regional air quality improvement.
PROTOTYPE SCENARIOS SELECTED FOR DETAILED ANALYSIS
Selection and Significance of the Scenarios
Based on the findings presented in Section II, a total of 20 prototype sce-
narios were selected for analysis and evaluation. These scenarios were de-
fined to encompass the most promising carpool/vanpool, reserved lane, and
transit improvement strategies and combination programs.
Ten of the scenarios deal with strategies which impact specific highway
corridors, thus affecting only a limited portion of total regional travel. The
analysis of these "localized" scenarios therefore focuses on their carbon
monoxide (CO) concentration impacts near the affected highway facilities.
The remaining ten scenarios have area wide travel impacts,, The analysis of
these latter, "regional" scenarios thus focuses on their regional pollutant
emission impacts.
The scenarios were designed with some systematic variation in assumed
travel impacts and area size to facilitate generalizing the project's findings.
However, the extent of this planned variation in assumed prototype conditions
was limited by the number of scenarios analyzed in total and the need for a
minimum degree of uniformity among scenarios (so that impact estimates
among different strategies would be comparable).
With this general background, the following specific points should be
made about the prototype scenarios:
. Although designed to be illustrative of typical implementation
conditions and the impacts of some variability in these condi-
tions, the scenarios should not be interpreted as yielding the
answer for a given strategy; nor do they span the range of typ-
ical variation in all major factors. As will be demonstrated
HL1
-------
later in this section, the air quality impacts of a specific strat-
egy implementation can vary substantially, depending on the
specifics (travel conditions, meteorology, highway geometries,
etc.) of the application.
. As a very rough surrogate for the variability in some of these
factors, the concept of "moderately favorable impacts" versus
"modest impacts" has been introduced into the description of
scenarios. Most of the scenarios assume "moderately favorable
impactSo " In other words, base modal split, congestion levels
and the advantages actually achieved by high occupancy vehicles
under the proposed actions are assumed to be those which result
in a reasonably favorable air quality impact (although within the
range of actual.past experience),, For comparison purposes,
several scenarios have been defined the same as another, ex-
cept for an assumption of "modest impacts,," The travel shifts
assumed for these scenarios are toward the lower end of past
experience, but not intended to be extremely unfavorable,
Localized Prototype Scenarios
Exhibit 7 describes the 10 prototype scenarios selected for analysis
of localized CO concentration impacts. These scenarios will be identi-
fied throughout this report by the ID number and brief title assigned
each in the exhibit,. The major descriptive features and travel impact as-
sumptions for each scenario are presented in the table. Further details on
the travel impact analysis methodology appear in Appendix A. The third
column of Exhibit 7 references illustrative diagrams in Exhibit 8 which dis-
play the highway facilities assumed for each scenario.
The first eight localized scenarios deal with the priority treatment of
high occupancy vehicles on freeways, while the last two deal with priority
treatment of buses on arterials. The programs being implemented in a sce-
nario typically consist of several complementary actions, such as reserving
a freeway lane, expanding express bus service, and providing park-and-ride
lots in the corridor. As indicated in Section n, such combinations are typi-
cal of actual transportation programs implemented throughout the nation,
Regional Prototype Scenarios
Exhibit 9 presents and describes the 10 scenarios selected for analysis
of regional HC, NOX, and CO emission impacts. Comments analogous to
those made above about Exhibit 8 and the localized scenarios apply here.
in. 2
-------
EXHIBIT?
LOCALIZED SCENARIOS SELECTED FOR DETAILED ANALYSIS
PHOTOTYPE SCENARIO
10
MO.
1
2
3
4
5
1
TTTIE
ftnuttt Extras B»
SontaohiMbnd
Frwwy Traffic?
FmraMtlnpKtt
Fraowoy UM Raurwd
fir Bum Md Cjrpoah;
FovonMo Import
Ron* Mourn* todta
Bv-Po»U»«:
Ronmd Bat/Pool
LMO. Ramp Mforini.,
Md tm Bv-PtJi Law;
Modcnlnpoca
ROOT* Bus/Pool
Lo»o.R.*»pMonriaf.
•d BOB By-fta Loow;
FnvnUv InpMti
LIM Ro*onod for
BOM; Foranblo
InfKtt
ILLUSTRATIVE
DIAGRAM*
A
A
B
B
B
C
DESCRIPTION OF THE
STRATEGY OR PROGRAM IMPLEMENTED
• 10MD*.BLiMFiiMir.N»R«n*
LlM
• Expnrf«ri. Rrtucri FM Expn« tm Srnki,
Opmtiiif l» Mb*d fimtmi TfifRe Owfof
PrtiP»rtodi
• Tim* 500 SpmPvk-Hd-RMi Lett !•
Condor
• 10 MB«, 1 Imt »m«y. WMnflow IBM
RMmd for BUM «M Ctrpogb (3+
OcnfMtt)
• ExpndtdEivnMBmSinictOmi
PMkPwiadi
• Ttaw 501 S(»e. Pwt-wd-Rid.no hi
Corridor
• 1SMRo.SL«iFraM«y;M*arnfof All
0»Rampi
• B« By-tai LM« «t 4 Run*
• ExoondodEiipnaBttSinicoOuriiii
PMk Pvnon
• Thru 508 Spoct P»rt-«id-R!d» Loa i*
Corridor
• 1SMi*,ILiMFrHiMv:Mfnrliiiaf All
On-Rwipi
* BBiBy-Pm U»«Jt4 Himpi
• Whfc-flow Lmo RoOTMd for tmm «d
Carpoab(3+ OCCHOOHB)
• ExpHdtd Exana Bat Soviet Ourint
Poik Pwiodi
• ThraoSOOSpKoPvk-Md-RidiLaliiii
Corridor
• SiMoiSeHorio4
• 10MBo,ILaMFroMtv;Off-F*»k
Dinctioa CaatnfloM Lmo Raurtid for
ExpnaBaoi
• ExMot Fraowiy Expiw Boi Strriet
Examdod Only to Moot lacnoud Oomtnd
MAJOR ASSUMPTIONS ON
CHANGES IN MODAL USAGE**
• SK liMoai in Fnowoy Exproa
B«RldonM*
• NolicroBOtaFroiMyCirooob
(Madunttly FivonMt lnpKO)
• IBM IncraH m Frwv*vExpniV
BM Ridmliip
* 100X locum in FrMNiy CMpodi
• 100% locnoH in Fraowoy Expnoi
BvRMonWt
• No liicroiio ia Fraomoy C*rpoob
(Modtn ImpKOl
• 7SX Inn mi in Fnowoy Expna Bin
RMonkip
• SOMncnoMiaFraiMOvCirpooli
INWvHltMV roWOfVOM ItnpKtSf
• 125% IBOOOII ia Frtonoy Expm
Boi Ridannif
• 9SXIaaoBoioFraMoyC*roaoli
(Modomnly FmonMo Impoeti)
• 5B% Inenow i* Fnonoy Expram
BoRidonfeip
• No IncrMil in Fntwry Cimooh
(ContiniMd)
•SEE EXHIBIT S FOR ILLUSTRATIVE DIAGRAMS OF THE PROTOTYPE HIGHWAY FACILITIES
"SEE APPENDIX A FOR FURTHER DETAIL OH METHODOLOGY AND TECHNICAL ASSUMPTIONS
HI. 3
-------
EXHIBIT?
LOCALIZED SCENARIOS SELECTED FOR DETAILED ANALYSIS (Cont'd)
PROTOTYPE SCENARIO
10
NO.
7
t
9
10
TITLE
Contraflow Bin Lm,
Expudod Expran Bus
Sonfeo, Md Pirk-oad-
Rido L
-------
EXHIBITS
ILLUSTRATIVE DIAGRAMS OF AFFECTED PROTOTYPE HIGHWAY FACILITIES
A. 8 LANE FREEWAY AND ADJACENT CORRIDOR ARTERIAL
-* 10 Miles
8 LANE
FREEWAY
6 LANE
ARTERIAL*
•Assume another 6-lane arterial and one 4-lane arterial in
corridor for travel shift purposes, but not crossing the
designated CO concentration impact area
CO Concentration
Impact Area (1 Mile Square)
B. 8 LANE FREEWAY WITH RAMP METERING AND ADJACENT CORRIDOR ARTERIAL
SAME AS DIAGRAM A, EXCEPT THAT THE FREEWAY IS EXPLICITLY ASSUMED
TO EXTEND OUT FROM CBD IS MILES AND THE LOCATION OF ON-RAMPS
(METERED) AND BUS BY-PASS LANES ARE NOW INDICATED (ONLY CHANGED
FEATURES SHOWN BELOW):
15 MILES-
/f
M
B
M M M M
B
M
/f / / /
M M MM
B
Diagram to scale only along horizontal
/f //////////
M M M M M M M M M M
B B
M — metered on-ramp
B — bus by-pass lane
>
S
^ S
* P
M <*
M £
CBD
6 LANE FREEWAY AND ADJACENT CORRIDOR ARTERIAL
6 LANE
FREEWAY
6 LANE
ARTERIAL*
AJW. PEAK CONTRAFLOW
CO Concentration
impact area (1 mile square)
•Assume another 6-lane arterial in corridor
for travel shift purposes, but not crossing
the designated CO concentration impact
area.
III. 5
-------
EXHIBIT 8 (Cont'd)
ILLUSTRATIVE DIAGRAMS OF AFFECTED PROTOTYPE HIGHWAY FACILITIES
D. 5 LANE ARTERIAL WITH REVERSIBLE MEDIAN
5 LANE
ARTERIAL
WITH REVERSIBLE
MEDIAN
LANE
"• • 1 u ivnies
•+ 1 Mile »•
1 ~ ~~\
No Parking i
P-
•*— IMile — ^
^
__ _ 1 i ^
i ^
1 ^
RFVFR
1 <
! <
No Parking i '
1 *>
1
. 1 /
L 1-
1 f
(A.M. PEAK CONTRAFLOW CURB BUS LANE) »J
No Parking | v
1 (
No Parking 1 '
* 1 c
i -I ^
r ^
, ^
r ~r
*" -I — C
». n
1 /•
No Parking '
<:
| <
i
i
i
CBD
I
, CO Concentration
impact area (1 mile square)
HI. 6
-------
EXHIBIT 9
REGIONAL SCENARIOS SELECTED FOR DETAILED ANALYSIS
10
No.
II
12
13
14
IS
11
PROTOTYPE SCENARIO
TTTIE
Hidlm Sin City;
FnmMolBiM
Urfo City; FmnMo
tapoca
R«rwd oWPo* UM.
RMj»Mot*tat,»dB«
BvPMUMMAI
Roomd B«/Pool Una.
R*mp Motoring ud Bw
Bv-PHUMonAI
FranMolnpKB
RMrnd Kbdm UM
far Expnu BUHI m
Appropriou RidW
Ararat); ModaalnipocB
« .
for ExprtM B»« til
A^ofri** fed*
Ararate; FivonMv
ImpocB
DESCRIPTION OF THE STRATEGY IMPLEMENTED
AND THE AFFECTED FACILITIES OR
TRAVEL MARKET*
of 200+ (40% of Employe*)
• Aramin VwpadProfrmi for Empby«n«f 1,000+
(20XafEiiiptoy«d
af200«-(35XttEnptoy«d
• Anmi4«V«Ki»oiProjraiiifof Employ*! of 1,000*
(17%ifEnfloyM)
• ExpMdtriRidwrtFinExpraaBuiScniaM
Framoyi
(3+ Occaptut) n Appnximinly 40 mte «f
1 UM «•*•! FIWMV
• (Ump Mrariif M OH-RMIDIIM:
10 tut By-Pw Rimpi
• g •«-"* Frin^ Pirkim F^ilt^
SniMaSaaMiU
• Niw Rfdwtd Fw» Expnm BIB Swia on Rtnmd
Rmnibl* MtdiM UM of 72 Mte of Mijor RidW
ArmMi
• SifMlPra-EimiiMforExpmBiMi
• ExpMdrtFiiMiPwkiiiiFMiiHfci
MAJOR ASSUMPTIONS ON
CHANGES IN MODAL USAGE**
• 1% of Emplaytti of Pwticipttiiif
Empl«vvs FormJIm CirpMh
• 3HofEmirii3VMofPwtidpMMf
Employ*! FormJNw VanpMti
• Apprax. 7% of EraployMi af Pmidpatiaf
Emplay*n Form Him C«fMoli
• 3%ofEmploy>oiafPirticia«tM|Emplovm
Fan* NM Vtupoob
(MaMrt ImpKt)
• 7§K IBCMOII h Affwttd Expno Biu VMT
• SOXIacnrainAffictM'CwMolVMT
• AmcMMriOMnimw Auto VMT
(Mtdmuty FnonM* IBIOKO)
• USNInBMMmAfhetMlExpnBBuiVMT
• 9S%liicnB*ii Affect* brood VMT
• A»oe»tW DocnMi in Auto VMT
(ModM Import
• VMT IIKTOBO for Expm Bin Aaaciatod
VMth 1 30K OvtnU (Lool and Expno)
B« Modri Split for Afftcnd Corridor
TnMl
• Aumiolod OOOTOM in Auto VMT
• VMT IncnM for Exprtn B« Anocand
VHtfc • 40% OMnN (Local md EXOTOB)
OH Modal Split for Afftcnd Corridor
Trmt
• AaocioUdOocnoHlnAiitoVMT
(Conamiod)
•ALL SCENARIOS EXCEPT FOR #11 ARE FOR A "LARGE" CITY (1,000.000+ SMSA POPULATION RANGE).
SCENARIO #111S SET IN A MEDIUM SIZED CITY (500.000 • 1,000.000 SMSA POPULATION RANGE).
"SEE APPENDIX A FOR FURTHER DETAIL ON METHODOLOGY AND TECHNICAL ASSUMPTIONS.
IE. 7
-------
EXHIBIT 9
REGIONAL SCENARIOS SELECTED FOR DETAILED ANALYSIS (Conf d)
PROTOTYPE SCENARIO
ID
No.
TITLE
DESCRIPTION OF THE STRATEGY IMPLEMENTED
AND THE AFFECTED FACILITIES OR
TRAVEL MARKET*
MAJOR ASSUMPTIONS ON
CHANGES IN MODAL USAGE
17
Carpooi/Vupaol Profnm
mt Fraaway floured
Lua;Modaa Impacts
Carpool/Vtnpooi Pragnm at Qauribtd in
Scenario 12
ExpaMladRadiicadFaraExprauBiBSarvicaan
Rotar*a4Wtb-RowLainforB«aaao4brpooli
(3+ Occupant) on Appraximataly 40 Miln of
1 Una Radial Fraamy
Expanded FrinfaPtrkiojFxaHtto
(Modan Impacts)
Carpool/Vanpool Componant
• 58% of VMT Impacts in Scanario 12
Ranread Lana Prooram Component!
• 55% Incneta in AHactad Expran Bin VMT
• 65% locraau in Affected Carpool VMT
Otentu in Auto VMT Asuciatad With
Abow Two ShHtx
11
Cwpoal/VMpool Program
tat Fnawoy R
FannoU Impact!
S*«MaScmano17
(Moderately FanraMe Impacts)
Corpeol/Vtnpool Componant
• Saraa Carpeol/Vanpool Impact! as
Scenario 12
Raterved Lane Program Compontno
• 100% Incrao* in Affactad Exprea Bin VMT
• 100% Increase in Affected Carpool VMT
• Docnaso in Auto VMT Associated With
Abovo Two Shite
19
Carpaol/Vaapool Program,
Riiarvad Umi, (tamp
Motarinj. ind Bus By-fan
L'anaj; Modcn Impicts
Carpool/Vanpool Program a Dtscribrt in Scanario 1 2
Ranrv*d Lana Fratinay Program ai Oascribid in
Scanario 13
(Modatt Impacts)
Carpool/Vanpool Componant
• 50% of VMT Impacts of Scanario 12
Froaway Program Component!
• Sama at Scanario 13
20
Carpoot/Vanpool Program,
Rtiinnd lim, Ramp
Mttarina, »d Bin By-Pan
Unai, Favonbla Impact!
Sama a Scaflario 19
(Modaratary FavoraUa Impacts)
Carpool/Vanpool Componant
• Sama at Scanario 12
Program Companum
i as Scanario <3
Fraaimiy Prog
• Samai
•ALL SCENARIOS EXCEPT FOR #11 ARE FOR A "LARGE" CITY (1.000.000+ SMSA POPULATION RANGE).
SCENARIO W11 IS SET IN A MEDIUM SIZED CITY (500.000 -1,000,000 SMSA POPULATION RANGE).
"SEE APPENDIX A FOR FURTHER DETAIL ON METHODOLOGY AND TECHNICAL ASSUMPTIONS.
HI. 8
-------
The first two regional scenarios (11 and 12) deal with areawide carpool/
vanpool programs focused on major employers in a prototype medium-sized
region (500, 000-1 million population) and large region (1 million + population)
respectively. Scenarios 13 and 14 deal with the application of a combination
freeway corridor strategy for several corridors throughout the region. Sce-
narios 15 and 16 do the same for a combination arterial strategy. The last
four strategies involve the combination of both areawide carpool/vanpool and
freeway corridor strategy components.
LOCALIZED SCENARIO IMPACT ESTIMATES
In this section, the following impacts are presented and discussed for
each of the 10 localized scenarios:
. travel impacts and highway noise impacts;
. localized CO concentration impacts;
. capital and operating costs; and
. economic impacts.
Travel and Highway Noise Impacts
The estimation of travel impacts for each scenario was a critical first
step in the analysis. Estimates of emissions, localized CO concentration,
and highway noise impacts all follow from the travel impact estimates.1 For
the localized scenarios which focus on specific freeway or arterial facilities,
these impacts include changes in vehicle volume and speed for each major
vehicle type (auto, carpool, bus, and truck).
Aside from their use as input to air quality and other impact estimates,
travel impact estimates are valuable for strategy or program assessment
and evaluation in their own right. Travel time and congestion impacts are
both significant evaluation considerations. Examining the detailed travel
impacts of a strategy under given prototype conditions can also supply val-
uable information on operational requirements (e. g., signing, enforcement)
and potential trouble areas; (e. g., congestion points, traffic "conflict" lo-
cations); ways in which a strategy might be implemented under specific con-
gee Table A. 1 of Appendix A for a flowchart of the overall analysis and im-
pact estimation procedure.
IE. 9
-------
ditions to provide more desirable impacts may also be suggested.
Exhibit 10 summarizes the major travel impacts estimated for the 10 lo-
calized scenarios. Vehicle volumes and average speeds for A.M. peak hour,
peak direction travel are given by vehicle type for both the base conditions
("before") and after the scenario strategy has been implemented ("after").
These values pertain to a segment of the primary highway facility in the pro-
totype corridor which has been selected as the focus of the illustrative CO
concentration impact area. This impact area is a one mile square which has
its inner edge approximately one mile from the CBD of the prototype region
for most of the scenarios.*
Exhibit 10 also presents information on the congestion impacts of each
scenario strategy in the form of "before" and "after" volume-to-capacity
(V/C) ratios for each prototype facility element in both the peak and off-
peak directions. Several major points should be made concerning the inter-
pretation of these impacts:
. The travel impacts reported are intended to be representative of
typical conditions and reasonable expectations for modal shifts,
but are nevertheless illustrative = The actual travel impacts
achieved in applying the scenario strategy or program to a spe-
cific corridor would depend on base travel conditions, highway
facility geometries, details of implementation, and similar fac-
tors prevailing for the specific application.
. In some cases, the removal of a lane from normal service and
reservation for use by high occupancy vehicles (HOV) results in
over-capacity congestion (V/C ratio greater than 1. 00) in the
remaining non-reserved lanes. Since stable flow conditions are
frequently lost and average speeds may not be reliably estimated
under such over-capacity conditions, speeds below the at-capac-
ity (level of service E) level are not reported in the table. How-
ever, these cases are noted and rough estimates of additional
stop-and-go delay are provided.
. In two of the scenarios (6 and 7), reservation of an off-peak di-
rection freeway lane for contraflow bus operation results in off-
peak direction traffic (which originally experienced good peak
hour flow conditions) facing capacity congestion levels.
illustrative diagrams in Exhibit 8 indicate the CO impact area with a
dotted line.
in. 10
-------
EXHIBIT 10
MAJOR TRAVEL IMPACTS FOR LOCALIZED SCENARIOS
10
No,
1
I
3
4
5
PROTOTYPE SCENARIO
TITLE
Expanded ExproB ta
Swin in Mbrtd rrtwuy
Tratncf FIVMWM iiujMcts
FiMnay lam RmamA
forfeMtoWCirpMb;
CeH«««feioiA l*OB^OB*>*
rnpvraBM iMpvc*
BMW Mrarinf mi Be*
ByPkBLaow;
Fmrakla l»poea
Rcnnod Bo/Pool
LJM, Ramp Motoring,
Md Boc By-Pa" LJM:
Modon Importi
Reonod Bin/Pod Laca.
B« 8y-P»B Laoaa;
Fewnble ImoocB
AJU. PEAK HOUR TRAVEL CONOITIO
PEAK DIRECTION VEHICLE VOLUMES AND
AVERAGE SPEEDS ON PRIMARY CORRIDOR FACILITY
On Corridor FraoMoy:
BEFORE AFTER
VaMcJtTvpt VPH MPH VPH MPN
AM BiW 21 tjUA U
Caned 33t 21 329 28
Boo 21 21 52 tt
Tiwk 380 2t 3W 21
7,800 B.770
(-3.1X)
OB Ciniter FrMny
BEFORE AFTER
V*idtTYP« VPH MPH VPH MPH
Am 6,290 21 Sjm 2BM
topMl 330 2B 800 43
torn a U SB 43
Track 350 2B 350 28**
7.008 8,0*0
M3.7M
(•fttawttd it ovw 0 J minijtB) e«nd by mr-c*paaty
COOHBtlOHb
Oi CoifMw fimttr.
BEFORE AFTER
VBOiCiw 1 YPQ VPH MPH VPH MPH
Am e5S H~ sJT5 IF
Cvpoal 330 2B 310 30
B« 28 2B SB 3B
Track 350 28 350 30
7,000 8330
(-8.7%)
On Cofridor Fmwy:
BEFORE AFTER
VikidtTvpc VPH MPH VPH MPH
Am 6^30 2B 4,440~28~
Cwpod 330 2B SOB 43
Bi> 28 a 52 43
Track 350 28 280" 28**
7,000 5.270"
(-24.7S**)
tklc to pn throng* bam* of brakdaMn of flow (i A,
miiMHa M franwy «*«*i • not nfl«ari in spMil
[ AftfeMfh ttMH tnwl HnpKtt sofjut tint M onraH wvmn*
gf tin imnctt pudnji CO conCTwtmiM rtnp»ct vtimXM
Oo Corrator FraoMty:
BEFORE AFTER
VokidoTypo VPH MPH VPH MPH
Am 4290 20 4,920 30
Cornell 330 20 840 43
B« 28 20 8» 43
Track 350 28 350 30
7,000 5,980
(-14.6%)
«S IN CO IMPACT AREA
VOLUME TO CAPACITY RATIO
CONGESTION LEVELS*
V/C RATIO*
BEFORE AFTER
Frotimry
Pock OinctiM 1 M OJ7
Off-Poik OiraniM OJ7 187
Corridor ArtorM
Pock DinctiM 0.75 0.74
Off-tak Olnetto* OJO ILSO
V/C RATIO*
BI-FpRtj AFTER,
Fr»t»»ty
ROHfY^LMt 11JM (U1
No^RcHrMd, Pock Ob-. 1 1JI2
Off-Port OincliOM LB7 OJ7
Corridor AitorW
Poik Dlractioo 0.75 8.70
Off-Port Difoctioi tJSO &50
Vrt RATIO*
BEFORE AFTER
FT^OIHBY
Port OinctiM 14)0 033
Off-Port Olmrfoo 0.67 0.87
Cocndor Aftvw
Poik Direction 0.75 0.73
Off-Port Direction 0.50 OJO
V/C RATIO*
BEFORE AFTER
RourndLtm 11.00 OJ1
Non-Rownrad. Port Oir. 1 1.12
Off-Poik Oireetioo 0.87 0.87
Corridor Artoriol
Pak Oireeti«i 0.75 0.72
Off-Pock Direct*. 0.50 0.50
V/C RATIO*
BEFORE AFTER
Friomoiy
RoHnod Lane 1 1.00 (Ml
Non-Roicnod, Pook Olr. 1 1.00
Off-Poik Oboctioo OJ7 0.87
Corridor Arterial
Port Direction 0.75 0.89
Off-Poik Dinctioii 0.50 0.50
•V/C RATIO IS THE RATIO OF VEHICLE VOLUME TRAVEL DEMAND TO FACILITY CAPACITY (LEVEL OF SERVICE "E".
1B"! HlfiHffftY rla>acrrY MANUAL).
in. 11
-------
EXHIBIT 10
MAJOR TRAVEL IMPACTS FOR LOCALIZED SCENARIOS (Cont'd)
ID
No.
•
7
t
9
10
PROTOTYPE SCENARIO
TITLE
Coatraflow Freaway Lam
Ranned for Buna;
Favorable Impacts
Contraflow But L«N,
Expanded Expraa Bus
Service, and Perk-end-
Ride Loo; Favorable
Impacts
Contraflow But Lao*,
Expanded Sonica, and
LoO;An«nine70V30%
Dkactioml Spttt:
Favorable Impact
Rosined Arterial Median
Lam for Expreti Bum;
Favoffaole Impacts
ConU allow Curt Lain
for Loot BUM on Pur
of Ono-Way Amriali;
Favorable Impact!
AJM. PEAK HOUR TRAVEL CONOITIO
PEAK DIRECTION VEHICLE VOLUMES AND
AVERAGE SPEEDS ON PRIMARY CORRIDOR FACILITY
On Corridor Freeway:
BEFORE AFTER
Vehicle Type VPH MPH VPH MPH
Auto 4.720 21 4J20 2B
Ceraool 250 20 240 21
8« 19 28 28 41
Truck 2W 2t 260 21
5458 5.850
MJ*)
On Corridor FranMy:
BEFORE AFTER
Vehicle Type VPH MPH VPH MPH
Auto 4.720 28 4,280 21
Carpool 250 21 220 2B
Bm 19 28 41 a
Track 260 28 260 28
5^50 4.810
(44%)
0* Corridor Freeway:
BEFORE AFTER
SAME AS SCENARIO 7
[Only the off-peak fmwey vohima vnn adjusted to achieve
the 79V30% imMd of tht lauri 60V40N dirwtlonl
ipKt Thk a reflocnd in a lovwr "tufora" V/C ratio for tht
off-ocak diraction in column to tha right! .
On Corridor Artarial:
8EFORS ARER
VahidaTypa VPH MPH VPH MPH
Auto 2,020 IS 1.440 15
Caroool 110 15 80 15
Local Bin IS 10 15 10
Expram Bui 0 • 28 23
Track 110 15 110 IS
2450 1.670
(-25JM
On Artarial Lama in In-Bound Diraction:
BEFORE AFTER
VahidaTvpa VPH MPH VPH MPH
Auto 2.660 IS 2.450 16
Canarf 140 IS 130 16
Local Ba 40 10 48" IS"
ExpnoBu. 5 15 5 16
Track 150 IS ISO 16
3,000 2.780
(-7JX)
"On contraflow bu» lam of out-bound artarial.
US IN CO IMPACT AREA
VOLUME TO CAPACITY RATIO
CONGESTION LEVELS*
V/C RATIO*
BEFORE AFT£R
rarSLctio. 1.00 ojs
Rawnad Contraflow Lana ) 0.02
Non-Raumd. Off-Paak Dir. Jfl.87 1JW
Corridor Artarial
Paak Diroctio* 0.75 0.74
Off^aak Oiracaan IL50 030
V/C RATIO*
BEFORE AFTER
FrBmny
Paak Oiraction 1.00 OJ1
Ranmd Comnflow Lam 1 0.04
NotHRaumd. Off-Paak Dir. 1 (L67 1JM
Corridor Artarial
Paak Diraction 0.75 0.73
Off-Pvak Diractioa 0.50 0.50
V/C RATIO*
IPORE AFTER
Freeway
Paak Direction 1.00 OJ1
Raonad Contraflow Lam \ 0.04
Non-Ranmd, Off4>aak Dir. 1 0.43 0.64
Corridor Artarial
fmk Oinction 0.75 0.73
Off-Paak Oiraction 0 JO 0.50
V/C RATIO*
BEFORE AFTER
Artarial
Non-Rasarvad. Paak Direction) 1.03
Rnarmd Median Lana (034 0.05
Off-Part Oiraction 034 034
V/C RATIO*
BEFORE AFTER
Artariah
Paak Okactioii 034 OJ5
Rturvtit Contraflow Una 1 0.63 0.09
Noo-RaMrad. Off-Paak Dir. / 033
, .. _ .. _
•V/C RATIO IS THE RATIO OF VEHICLE VOLUME TRAVEL DEMAND TO FACILITY CAPACITY (LEVEL OF SERVICE "£'.
1965 HIGHWAY CAPACITY MANUAL).
III. 12
-------
This has both air quality and obvious political feasibility impli-
cations. However, in scenario 8, where a more extreme direc-
tional split of 70 percent/30 percent is assumed (instead of 60
.percent/40 percent), the off-peak direction congestion impacts
are reduced, illustrating the importance of prevailing travel
condition details in determining the air quality impacts.
In the absence of details on highway geometries, topography, vegetation,
etc., it is difficult to quantitatively estimate the noise impacts for the local-
ized scenarios. However, the overall peak hour vehicle volume reductions
reported in Exhibit 10 are significant (as high as a 26 percent reduction for
scenario 9), suggesting the potential for noticeable highway noise reductions.
Given equal volumes and volume changes, the noise impacts from arterials
are likely to be more significant than those from freeways since freeways
frequently are separated from population concentrations by greater dis-
tances, have better acoustical insulation, and have less vehicular acceler-
ation and deceleration. However, the higher operating speeds on freeways
do tend to counterbalance these factors to some extent.
Localized CO Concentration Impacts
Based on the above travel impacts, line source emission strengths on all
corridor facilities in the CO concentration impact area were calculated for
each localized scenario. An expanded version of the EPA HIWAY model was
then used to estimate "before" and "after" CO concentrations associated
with highway traffic on the affected prototype facilities for 121 receptor grid
points covering the one mile square impact area.
For each localized scenario, CO concentration impact estimates were
made for each of three prototype meteorological conditions: (a) typical good
dispersion (this general type of condition is most likely to prevail); (b) typ-
ical poor dispersion (less likely to prevail); and (c) extremely poor disper-
sion (least likely to occur). Exhibit 11 defines these three prototype mete-
orological conditions and illustrates the variation in CO concentrations over
the three different assumptions using results for scenario 2. Total concen-
trations and concentration impacts are both several times higher under ex-
tremely poor dispersion conditions than under either of the two other pro-
totype conditions. Thus, prevailing meteorological conditions are a very
critical factor in determining the localized CO impact actually realized.
However, because of the relative infrequency of conditions similar to those
specified for extremely poor dispersion, comparisons among scenarios in
subsequent exhibits will be made with only the first two meteorological con-
ditions.
IIL13
-------
EXHIBIT 11
ILLUSTRATING THE IMPACT OF PREVAILING METEOROLOGICAL CONDITIONS ON A.M. PEAK HOUR CO CONCENTRATIONS*
CONCENTRATION
ASSOCIATED WITH
FACILITY EMIS-
SIONS,
BEFORE
IUPI riiruTATinue
H
REDUCTION CAUSED BY
PROGRAM
CONCENTRATION ASSOCIATED
WITH FACILITY EMISSIONS.
ACTCD II1DI CUCUTATinU
A.M. PEAK HOUR
CO CONCENTRATION
AT RECEPTOR SO
FEET FROM DOWN-
WIND EDGE OF FREE
WAY IN
40.000
36.000
32.000
28,000
!•
24000
20,000
16.000
12000
6,000
4.000
0
-
-
rrr 1
•1
rrrrrsrrn
B
HI
C
CODE
LABEL
WIND
DIRECTION t
WIND SPEED
TEMPERATURE
fiTARII ITV
CLASS
MIXING
DEPTH
ASSUMED METEOR
A
TYPICAL GOOD
DISPERSION
PERPENDICULAR
TO PRIMARY
CORRIDOR
FACILITY
4m/sec.
75°F
Q
(NfuUil)
700irwtan
OLOGICAL CONDITIO
B
TYPICAL POOR
DISPERSION
PERPENDICULAR
TO PRIMARY
CORRIDOR
FACILITY
4m/sec.
32°F
£
(Stabk)
400imten
NS
C
EXTREMELY POOR
DISPERSION
20* OFF OF
PARALLEL TO
PRIMARY
CORRIDOR
FACILITY
2 m/iec.
32°F
C
(VwyStabte)
2MnMtMS
•Thf Ulustrativ* CO concentrations dnpliyed In thb txhikh
in for tctnario 2. Tht concmtritiora m butd on
vahkulir tmittiom from ifftcttd fratiMy and HttrW
Mly Md WMM Mtattmyttd traf He ttow coidltitM.
-------
As mentioned above, CO concentration estimates were made using an
11x11 grid of receptor points covering the impact area. Exhibit 12 illus-
trates the spatial variation in CO concentrations around the prototype free-
way and arterial along cross-sectional profile lines at each end of the im-
pact area, again for scenario 2. Along both cross-sectional profiles, CO
concentrations peak just downwind from the freeway. Concentrations from
the affected facilities are substantially higher in this area than at any other
location along the profile line. Concentrations drop off to less than one-half
their maximum receptor value at a distance 0. 1 mile further downwind.
As between the two cross-sectional profiles, maximum concentration is
slightly higher at the end where the freeway and arterial center lines are
separated by only one-quarter mile. However, the area of significant con-
centration levels is also significantly compressed. It should be emphasized
that these concentration estimates do not include "background" CO concen^""
trations from stationary sources and highway facilities not directly affected
by the scenario strategy, and do not reflect CO concentrations at distances
less than 50 feet from the edge of the roadway. The effects of these factors
on CO concentrations are illustrated later in this section.
The CO concentration at a grid receptor point 50 feet downwind from the
edge of the primary corridor facility under study is used as the basis for
comparing localized scenarios in subsequent exhibits.
Exhibit 13 is the first of three which compare the localized CO concen-
tration impacts of scenarios with similar prototype conditions. Exhibit 13
compares the four scenarios involving an eight-lane freeway as the primary
corridor facility. Because of travel impact complications resulting from
the projected breakdown of non-reserved lane flow on the freeway, CO con-
centration impact estimates could not be reliably estimated for scenario 4,
which was therefore excluded from this exhibit. However, the projected
travel impacts for scenario 4 could be expected to result in a general wors-
ening of localized air quality during the A. M, peak period.
For each of the four eight-lane freeway scenarios treated in Exhibit 13,
CO concentration results for both typical good and typical poor dispersion
conditions are presented. Each bar illustrates the "before" and "after" con-
centrations associated with the affected highway facilities, as well as the
implicit concentration change. For these four scenarios, the impact of the
implemented program or strategy is always a reduction in CO concentration
(as measured at the referenced grid receptor 50 feet from the edge of the
freeway.
III. 15
-------
EXHIBIT 12
ILLUSTRATING THE SPATIAL VARIATION IN A.M. PEAK HOUR CO CONCENTRATION AROUND PROTOTYPE HIGHWAY FACILITIES*
ARTERIAL
FREEWAY
10.000
1.000
1,000
A.M. PEAK HOUR
CO CONCENTRATION
'» , 4.000
2.000
0
ASSUMED METEOROLOGICAL CONDITIONS
Wind Pirpwdkulu U Fraowiy. it 4 miUn/HC.
32% F
Stability Ctra E (SUM*)
Mixini Dipt* of 400 mrtm
I LANE
ARTERIAL
I LANE
FREEWAY
2 .3 .4 .6 .1 .7
DISTANCE SCALE (MILES)
A+
BEFORE PROGRAM
AFTER IMPLEMENTATION
A.M. PEAK HOUR
CO CONCENTRATION
IN
10.000 -
1.000 -
1.000 -
ION*
4.000 -
2.000 -
0 _
ARTERIAL
FREEWAY
WIND
.1 J .3 .4 .t .8 .7 .1
DISTANCE SCALE (MILES)
•Tfc« olustntwi CO coaciutratiom dapbyid ia this nhiaH in far Scuuri• 2.
Th> caaCMitntiaat m basid oa vthicuhr •aibsiom from III* iffecMd IrMWiy
tat irtwiil only.
NOTE:
Tin ibon iM Hgnwnt plats cooaict ditcratt nnptor
caoctDUitioi) viluM (it 0.1 mil* iaUnuli) tad in oat
bmadcd to Kcuiitaly portiiy connnuitioni (MIMMID
thtttaoliu.
X - MAXIMUM CONCENTRATION
RECEPTOR
-------
EXHIBIT 13
LOCALIZED CO CONCENTRATION IMPACTS* : COMPARISON OF SCENARIOS INVOLVING 8 LANE FREEWAYt
AJH.PEAK
HOUR CO
CONCENTRATION*
AT RECEPTOR
SO FEET FROM
DOWNWIND EDGE
OF FREEWAY
IN
1.000
7.SOO
;.eoo
6.SOO
0.000
S.SN
5,000
4.500
4000
3.500
3.000
2.500
2,000
1,500
1.000
SOO
.
.
'
•
.
A
1
B
1
A
1
B
1
A
I
B
A
1
" / / /- // / / # /
>/////>'/
/*j? •$/ //* '*/ /** -f/ /£S •//
^/A/A/M/
1
"IMPROVED CO LEVELS"
• i j •.
/
CONCENTRATION 1
ASSOCIATED WITH 1
FACILITY <
EMISSIONS. 1
BEIflBJ I
IMPLEMENTATION v
1
1
JL
1 REDUCTION CAUSED
I BY PROGRAM
1 CONCENTRATION
ASSOCIATED
WITH FACILITY EMISSIONS.
AFTER IMPLEMENTATION
"WORSENED CO LEVELS"
CONCENTRATION /
ASSOCIATED WITH)
FACILITY /
EMISSIONS. I
AEIEJ 1
IMPLEMENTATION \
i
—
I INCREASE CAUSED
1 BY PROGRAM
CONCENTRATION
ASSOCIATED
WITH FACILITY EMISSIONS,
BEFORE IMPLEMENTATION
METEOROLOGICAL CONDITIONS9
A : Typical. Good ObpcniM
B Typical. Paw OBpmimi
eSEE EXHIBIT 11 FOR DETAILS
*CO concentrations are based on vehicular emissions from affected
/ freeway and/or arterial facilities only and assume uninterrupted traffic
flow conditions. Other sources of CO emissions can be substantial, but
would not be affected by the programs being analyzed.
tFor reasons discussed in the text. CO concentration estimates for
Scenario 4 could not be reliably estimated and therefore do
not appear.
-------
The greatest reduction in CO concentration is achieved by scenario 5,
the most ambitious combination freeway program, with a reduction in excess
of 10 percent of the initial highway-related concentration. The smallest re-
duction is achieved by scenario 1 (approximately 2.5 percent relative to ini-
tial concentration), which is the least ambitious freeway program, calling
only for the expansion of express bus service in mixed traffic and provision
of park-and-ride facilities. The impacts are significant, but not large on a
percentage basis, especially when one adds background CO to the base
highway concentrations displayed.
As illustrated by the significantly different outcome for scenario 4
(which was simply scenario 5 with more modest modal shift assumptions),
one should be aware that the magnitude and even sign of these illustrative
prototype impact estimates can easily vary from those achieved in a specific
actual application, depending on the factors already discussed.
As noted above, the CO concentrations presented in Exhibits 13, 15 and l
16 do not include background CO concentrations. Using a 5,700 pig/m3(5 ppm)
background CO concentration in conjunction with the CO concentrations in
these exhibits indicate that none of the scenarios violates the 1-hour NAAQS
for CO of 40,000 /^.g/m3 (35 ppm). However, Exhibit 14 illustrates that se-
lected scenarios which do not violate the 1-hour CO standard can approach
or exceed the 8-hour CO NAAQS of 10,000 ng/ui3 (9 ppm).
For example, a peak 1-hour CO concentration of approximately 8,000 jig/m3
(for vehicle emissions only) is shown for the before condition for scenario
5 in Exhibit 13. This corresponds to an approximately 11,000 fig/m3
maximum 8 -hour CO concentration (including background) at a distance
of 25 feet from the edge of the roadway, which exceeds the 8 -hour NAAQS
for CO. After implementing the transportation measures in scenario 5, the
maximum 8-hour CO concentration is estimated at 10, 200 ng/ir? at 25 feet
from the edge of the roadway. The latter concentration just exceeds the
8 -hour CO standard and represents an important reduction in CO concen-
trations.
This example and Exhibit 14 illustrate the following important points:
. In those scenarios in which peak 1-hour CO concentrations
from vehicular traffic alone approach or exceed 7-000 pig/m
(at a distance of approximately 50 feet from the edge of the
GCA Corporation. Identification of Localized Violation of Carbon Monoxide
Standards - Volume I; Guidelines (Draft Final Report). Prepared for EPA-
Region I office, November 1975, pg. 11-13.
HI.18
-------
EXHIBIT 14
RELATIONSHIP BETWEEN MAXIMUM 8-HOUR AND PEAK 1-HOUR
CO CONCENTRATIONS FOR TYPICAL, POOR DISPERSION CONDITIONS*
11.000
10,000
£
5
9,000
o
u
8,000
x
7.000
Distance from edge of roadway = 25'
NAAQS for CO (8-hour)
I
Distance from edge of roadway =• 50'
Scenario 5 "After" Case
J
L
Scenario 5 "Before" Case
5,000
6,000
7,000
1,000
PEAK 1-HOUR CO CONCENTRATION FROM VEHICULAR TRAFFIC ONLY (jig/m3)
(Reed from Exhibits 13,15, and 16)
> Assumptions:
1. Concentrations reflect typical, poor dispersion conditions.
2. A background CO concentration of 5,700 ug/m3 (5 ppm)
is assumed driving the peak 1-hour.
3. A 0.7 ratio of the maximum 8-hour to peak 1-hour CO con-
centration is assumed.
4. A factor of 1.25 was used to convert CO concentrations (from
vehicular volumes only) at 50 feet from the edge of the road-
way to CO concentrations at 25 feet from the edge of the roadway.
5. Estimated CO concentrations assume uninterrupted traffic
flow conditions.
III. 19
-------
roadway), the 8-hour NAAQS for CO may be violated under
typical, poor dispersion conditions at locations approximate-
ly 25 feet from the edge of the roadway.
. At a distance of 50 feet from the edge of the roadway, peak
1-hour CO concentrations (from vehicle traffic alone) ex-
ceeding approximately 8,000 ng/m3 suggest that the 8-hour
CO standard may be violated under typical, poor meteoro-
logical conditions.
Exhibit 14 can be used in conjunction with Exhibits 13, 15 and 16 to pre-
pare approximate estimates of maximum 8-hour CO concentrations for the
localized scenarios.
In Exhibit 15, the localized CO impacts for scenarios involving a con-
traflow bus lane on a six-lane freeway are presented. Note that even with
a favorable impact assumption, both contraflow bus lane scenarios yield
net increases in CO concentration when the peak hour directional split of
traffic is 60 percent/40 percent. This result stems from the condition that
increased congestion in the remaining off-peak direction lanes more than
counterbalances the emission reductions achieved by the projected shift
from autos to express bus.
However, when the base A.M. peak hour off-peak direction traffic is
assumed lighter (corresponding to a 70 percent/30 percent directional
split), the same strategy used in scenario 7 produces a net CO concen-
tration reduction in scenario 8. In all of these cases, the net percentage
impact is less than 5 percent, but these prototype results again demon-
strate the importance of site-specific details, such as peak traffic direc-
tionality, in determining both the magnitude and sign of the impact.
Exhibit 16 presents the CO concentration impacts for the two arterial
program scenarios. While the absolute changes are not large relative to
the national standard, the estimated percent reduction in CO concentration
achieved by the reserved median bus lane strategy in scenario 9 is substan-
tial (approximately 15 percent). However, this scenario is based on the
assumption of a total (local and express) bus modal split of 40 percent in
the corridor, which is reasonable, but may not be easily achieved in some
areas.
The results for the contraflow curb bus lane are mixed. Since a pair
of one-way arterials is involved, two maximum receptor concentration
points are present. In this case, the increase in concentration adjacent to
the arterial with the contraflow lane (caused by increased congestion in the
m. 20
-------
EXHIBIT 16
LOCALIZED CO CONCENTRATION IMPACTS* : COMPARISON OF SCENARIOS INVOLVING CONTRAFLOW LANE
ON 6 LANE FREEWAY
AJM. PEAK
HOUR CO
CONCENTRATION*
AT RECEPTOR
M FEET FROM
DOWNWIND EDGE
OF FREEWAY
IN
CO
I.DOI
7.500
7.000
8.500
6.000
5.600
5.000
4.500
4.000
3.500
3.000
2.500
2.000
1.500
1.000
500
•
I
A
I
B
I
A
B
Nolt: Scitiari* 1 is nat
completely comparable with
Sctiurioi 6 and 7 bicaun
tin chante hi attorned
directional split ol traffic tho
mulled in loww fatal base
nhklt volumes.
However, the direction
and relative site ef the
conceptration impacti can
be piofitalilv comparad.
^E
A
I
B
"IMPROVED CO LEVELS"
CONCENTRATION I
ASSOCIATED WITH I
FACILITY {
EMISSIONS. I
BiEflHf I
IMPLEMENTATION v
REDUCTION CAUSED
(V PROGRAM
} CONCENTRATION
I ASSOCIATED
I WITH FACILITY EMISSIONS.
J AFTER IMPLEMENTATION
"WORSENED CO LEVELS"
CONCENTRATION /
ASSOCIATED WITH I
FACILITY I
EMISSIONS. I
AFTER
IMPLEMENTATION I
Til INCREASE CAUSED
| I BY PROGRAM
CONCENTRATION
I ASSOCIATED
WITH FACILITY EMISSIONS.
BEFORE IMPLEMENTATION
METEOROLOGICAL CONDITIONS*
A : Typical. CM* Dnptnim
B : Typical. Pool Dispersion
eSEE EXHIBIT II FOR DETAILS
*CO concentrations are based on vehicular emissions from affected
freeway and/or arterial facilities only and assume uninterrupted traffic
flow conditions. Other sources of CO emissions can be substantial, but
would not be affected by the programs being analyzed.
-------
EXHIBIT 16
LOCALIZED CO CONCENTRATION IMPACTS* : COMPARISON OF SCENARIOS INVOLVING RADIAL ARTERIALS AS
THE PRIMARY FACILITY
to
to
AJW. PEAK
HOUR CO
CONCENTRATION*
AT RECEPTOR
SO FEET FROM
DOWNWIND EDGE
OF RELEVANT
ARTERIAL IN
MB/meter3
8,000
7,500
7,000
6,500
6.000
5.500
5,000
4,500
4.000
3,500
3,000
2,500
2,000
1,500
1.000
500
n
•
.
m
_
-
•
.
•
•
•
•
-
-
-
-
-
f,l<"
If:
A
-------
remaining off-peak lanes) conies close to matching the decrease in concen-
tration adjacent to the peak direction arterial (caused by the projected shift
from autos to local bus). The end result is to increase congestion adjacent
to the off-peak arterial to a level higher than that originally around the peak
direction facility and to reduce the congestion adjacent to the peak direction
facility to a level below that originally around the off-peak arterial. How-
ever, as illustrated in Exhibit 15, this particular result could have been
substantially different if a more extreme directional split of traffic on the
two arterials had been assumed.
Capital and Operating Costs
Exhibit 17 presents the estimated capital and annual operating costs for
the localized scenarios. Appendix B presents the unit costs used in the de-
velopment of the capital and annual costs. The costs presented in Exhibit 17
are order of magnitude estimates based on costs published in the literature.
The largest individual cost item for all of the scenarios is for improve-
ments to express bus service. Generally, the geographic coverage and the
frequency of express bus service were assumed to increase significantly in
order to complement the reserved HOV lanes and attract large numbers of
auto travelers. The annual cost of bus service shown in Exhibit 17 repre-
sents the incremental cost of providing bus service above that assumed in
the base case (i.e., "before" case).
The costs of implementing ramp metering and park-and-ride facilities
are also significant. With regard to the cost of park-and-ride lots, two con-
ditions are assumed. If use can be made of existing parking facilities at
shopping centers or other locations, the capital cost of such facilities would
be negligible. However, such arrangements may not be feasible in many
locations, and the full capital cost of constructing the park-and-ride facili-
ties is also presented (the two capital cost values are separated by a slash
in Exhibit 17). For both of these conditions, the cost of operating and main-
taining the park-and-ride lots is assumed to be a public cost.
Based on analyses of express bus operations in Minneapolis (i. e., I-35W
projects) and Seattle (i. e., Blue Streak project), annual operating revenues
may only offset approximately 50 percent to 66 percent of the annual operating
and maintenance costs of express bus service shown in Exhibit 17. Conse-
quently, sizeable annual operating subsidies may be required to operate ex-
press bus services such as those assumed in the localized scenarios. If
fare reductions are implemented, the subsidy requirements are likely to be
even more significant.
IIL23
-------
EXHIBIT 17
CAPITAL AND ANNUAL OPERATING AND MAINTENANCE COSTS
FOR LOCALIZED SCENARIOS
to
PROTOTYPE SCENARIO
ID NO.
1
2
3
4
TITLE
Expanded Express
Bus Service in Mixed
Freeway Traffic;
Favorable Impacts
Freeway Lane Reserved
for Buses and Carpools;
Favorable Impacts
Ramp Metering
and Bus By-Pass Lanes;
Favorable Impacts
Reserved Bus/Pool Lane,
Ramp Metering , and
Bus By-Pass Lanes;
Model Impacts
COSTS (IN THOUSANDS OF 1976 DOLLARS)
ITEM
Park and Ride Lots Express
Express Bus Service
Reserved Lane
Park and Ride Lots
Express Bus Service
Ramp Metering
Bus By-Pass Ramps
Express Bus Service
Park and Ride Lots
Ramp Metering
Reserved Lane
Bus By-Pass Ramps
Express Bus Service
Park and Ride Lots
CAPITAL
$0/1,620
3.168
3,168/4,788
100
0/1,620
3,630
3.720/5,350
1,134
460
3,630
0/1,620
5.224/6,844
1,134
100
460
3,168
0/1.620
4,862/6,482
ANNUAL OPERATING
AND MAINTENANCE
$248
1,199®
1,447
220
248
l.371@
1,839
84
1,371®
248
1,703
84
220
1,1 99®
248
1,751®
@ This represents the incremental annual operating and maintenance costs of providing bus service beyond existing
bus service.
Note: The cost projections have been prepared on the basis of the assumptions set forth in Appendix B.
The actual costs of the above strategies will depend upon the specific setting in which they are implemented.
-------
EXHIBIT 17 (Continued)
to
Ul
PROTOTYPE SCENARIO
ID NO.
5
6
7
8
9
10
TITLE
Reserved Bus/Pool
Lane, Ramp Metering and
Bus By-Pass Lanes; Favorable
Impacts
Contra-Flow Freeway Lane
Reserved for Buses;
Favorable Impacts
Contraflow Bus Land
Expanded Express Service,
and Park and Ride Lots;
Favorable Impacts
Contra-Flow Bus Lane
Expanded Service, and Lots
Assuming 70X/30X Directional Split;
Favorable Impacts
Reserved Arterial
Median Lane for
Express Buses;
Favorable Impacts
Contraflow Curb
Lane for Local
Buses on Pair of
One-Way Arterials;
Favorable Impacts
COSTS (IN THOUSANDS OF 1976 DOLLARS)
ITEM
Ramp Metering
Reserved Lane
Bus By-Pass Ramps
Express Bus Service
Park and Ride Lots
Contra-Flow Lane
Express Bus Service
Contra-Flow Lane
Express Bus Service
Park and Ride Lot
Contra-Flow Lane
Express Bus Service
Park and Ride Lot
Reserved Median Lane
Express Bus Service
Park and Ride Lot
Contra-Flow Curb Lane
Bus Service
CAPITAL
1,134
100
460
4,554
0/1,620
6.248/7.868
500
462
962
500
3,168
0/1.620
3,668/5.288
500
3.168
0/1,620
3,663/5,288
1,350
2,244
0/540
3,594/4.134
6
462
468
ANNUAL OPERATING
AND MAINTENANCE
84
220
1,714®
248
2.266
220
321«
541
220
1,3500
248
1.818
220
1,3500
248
1,818
29
1,0299
82
1,130
123
123
-------
Economic Impacts
The economic impacts of the localized scenarios are likely to be small.
There is little evidence in the literature which suggests that any of the local-
ized transportation measures considered have any measurable effects on em-
ployment, retail sales, or related economic factors.
Economic benefits in the form of travel time and travel cost savings
are likely to be realized by travelers attracted to transit and ride-sharing
programs. For example, a 10 mile trip on a reserved freeway lane is es-
timated to yield a 6 to 8 minute reduction in travel time as compared with
the same trip made on the non-reserved freeway lanes. Similarly, signifi-
cant travel cost savings in the form of reduced gasoline, insurance, main-
tenance, and parking costs can be achieved by those travelers who diverted
from single occupant vehicles to either transit or carpools/vanpools
The combination of expanded bus service and reserved freeway or arte-
rial lanes will improve the accessibility to the CBD in the affected corridors.
This may induce non-work trips to the CBD even if the express bus service
is primarily intended for peak period travelers.
REGIONAL SCENARIO IMPACT ESTIMATES
In this section, the following impacts are presented and discussed for
each of the 10 regional scenarios:
. travel impacts;
. regional HC, NO , and CO emission impacts;
. regional fuel consumption impacts;
. capital and operating costs; and
. economic impacts.
Travel Impacts
As for the localized scenarios, estimation of travel impacts is also a
critical first step in the analysis of the regional scenarios. For the regional
scenarios, travel impacts are expressed in terms of changes in regional
weekday vehicle miles travelled (VMT). For the purpose of estimating re-
gional emission and fuel consumption impacts, the VMT changes are allo-
cated to road type, vehicle type, and average speed groups.
IIL26
-------
Exhibit 18 summarizes the travel impacts for the 10 regional scenarios.
With the exception of the first scenario,, all pertain to the large prototype
region (in the 1,000,000+ SMSA population range). Scenario 11 is set in the
medium-sized prototype region (500a 000-1, 000, 000 SMSA population range).
For each regional scenario, Exhibit 18 presents the absolute "before" and
"after" regional weekday VMT as well as the percent change this represents.
In addition, the VMT change is also expressed as a percent of regional work
trip VMT and (where appropriate) as a percent of the total VMT estimated
to be directly affected by the scenario program. These last two percentage
impact values are intended to provide a better indication of the strategy im-
pact within the affected travel market (which can be substantially smaller
than total regional travel).
The following major observations are relevant:
. although the absolute quantities are different, the percentage
changes in regional VMT for the carpool/vanpool program ap-
plied in both the medium-sized and large prototype regions are
essentially the same;
. the carpool/vanpool program, focused on major employers, is
generally several times more effective in reducing regional VMT
than multiple areawide application of the corridor strategies,
primarily because it has a larger affected travel market;
. carpool/vanpool programs can be combined with multiple ap-
plications or radial corridor strategies with little competitive
overlap of individual impacts, since the two affected travel mar-
kets are largely mutually exclusive when the programs are cor-
rectly implemented; and
Regional HC, NOX, and CO Emission Impacts
»
Using the latest EPA mobile source emission factors for 1978,1base con-
dition weekday regional highway emissions were calculated for the medium-
sized and large prototype urban regions. Changes in weekday regional high-
way emissions were calculated for each of the 10 regional scenarios. Re-
gional emission estimates were made for hydrocarbons (HC), nitrogen oxides
(NOX), and carbon monoxide (CO).
All of the emission estimates were made for the standard reference con-
ditions of 75° F and 75 grains/b. absolute humidity. However, a limited
As of February 1978.
in. 27
-------
EXHIBIT 18
MAJOR TRAVEL IMPACTS FOR REGIONAL SCENARIOS
to
00
PROTOTYPE SCENARIO
10
Ho.
11
12
13
14
»
IS
17
11
11
29
TITLE*
Carpaol/Vaopool Piofram, Madium
Siu City; Favorehla Impacts
Carnool/Vanpoal Program, Larga
City; FnonUi Impacts
Rturnd Bus/Pool Lta«. Ramp
Matarug. and Bus By-Pass Lanas
oa AH Appropriate Fnaways;
Malta Inputs
Rjasarad Bus/Pool Lanas, Ramp
Mowing, and But By-Pass Lanas
M All Apt* opriata Fraamays;
Fawuibb bapactt
Busas M Aporapriata Radial
Artariab;Mod«l Impacts
Rosanad Madian Lint for Exprasi
Busas on Apprapriala Radial
Arlariab; Favorabla Impacts
Caipool/ Vaopool Program and
Fcaaway Rasarvad Lanas;
Uodait Impacts
Carpool/Vaiipaol Program and
Fraamy Rasarvad Laaw;
FavanUa Impacti
CarpoolAfaapool Piopim. Rssamd
Lanas, Ramp Milariui, and Bus By-
Pass Lanas; Uodast Impacts
Ci«poi4/Vanpoal Pregraa. Ra-
sarwd Lams, Ram* Matarinf, and
Bus By-Pan Lanas; Favorabla
Impacts
WEEKDAY REGIONAL VMT"
BEFORE PROGRAM
IMPLEMENTATION
8.M6.BOO
43.S4S.OOO
43,946.000
43.S4S.OM
43,846,008
43,946,000
43.t4S.000
43.S4fi.OaO
43.946,000
43,145.000
AFTER PROGRAM
IMPLEMENTATION
9,689.000
43,287,000
43.S3S.OOO
43.7SO.OOO
43.S4S.OOO
43.77S.OOO
43.S12.OOt
43.110.000
43.SOS.OOO
43.092.000
PERCENT
CHANGE IN
TOTAL REGIONAL
VMT
-1.SX
-1.SX
-USX
-0.44X
-OJ3X
-0.3IX
-1.0X
-1.IX
-1JX
-1JX
PERCENT CHANGE
RELATIVE TO
WORK TRIP
REGIONAL VMTt
-S.OX
-SJX
-0.8X
-1.6X
-O.SX
-1JX
-3JX
-SJX
-3.3X
-S.SK
PERCENT CHANGE
RELATIVE TO
"AFFECTED"
REGIONAL VMT9
N.A.
NX
-8.1X
-10.SX
-13.8X
-23^X
NJk.
HA.
N.A.
N.A.
•AM scaoarios auapt fw #11 ara l« a "lar|i" chy (1,000,0001SMSA population).
Scanaria 11 is sat in a "madium sUa" city (500,000 1.000,000 SMSA population).
"Vattida nilas tnvrilad on an avaraga tvoikday in tha ration
tWork trip VMT is astimatad at 30X of total weekday ragional VMT.
y*AKacttd" Reiional VMT. For Scanariu 13 and 14: Consists of paak pariod. paak diiKtioa VMT animatad to ba on:
(a) radial fraaMy satmants kaving tha rawrved lana and M major radial artariab within tha affwild
fraaway corridors. For Scanarios IS and IE: Peak pariod, paak direction VMT astimatad to ba an roughly
72 miles of major radial artariak with a nsermd madian lana.
-------
number of estimates were also made for 32° F and absolute humidity of 15
grains/lbs. for comparison purposes. Exhibit 19 illustrates the variation
in regional emissions associated with these two different temperature and
humidity assumptions. While emissions are higher at the lower temperature,
it should be pointed out that photochemical oxidant problems are typically
worst during periods of warm weather when atmospheric conditions favor
the formation and concentration of oxidants near the surface.
Exhibit 20 presents the estimated emissions and fuel consumption reduc-
tion impacts of a carpool/vanpool program for both the medium-sized and
large prototype regions. As expected, the absolute quantities are propor-
tionally higher for the large region, but the percentage impacts are virtually
identical for the two regions, without a consistent advantage to either across
the four impact indices. All subsequent impact comparisons among regional
scenario strategies and programs will be based on the large prototype region
as the standard.
Exhibits 21 through 23 compare the nine regional scenarios for the large
prototype region in terms of their HC, NOX, and CO emission impacts, re-
spectively. Regional HC and NOX emissions are primary inputs to the pro-
cess which produces photochemical oxidants in urban areas. Regional CO
emissions are of less significance since CO is primarily a localized air
quality concern.
Overall, the emissions impacts tend to reflect the percentage VMT im-
pacts.1 This is most true for NOX emissions. However, the speed sensitiv-
ity of the most recent EPA emission factors for HC and, even more so, CO
have resulted in percentage change emission impacts for some scenarios
which are significantly different from the corresponding VMT impacts. As
illustrated in Exhibits 21 and 23, some of the strategies involving reserved
lanes on freeways and arterials are estimated to yield increases in HC and
CO emissions, respectively, despite the achievement of overall VMT reduc-
tions for these same strategies.
Because of the sensitivity of HC and CO emissions to vehicle speed, the
shifts of VMT to slower average speed classes (estimated to result from
Exhibit 28 presents a tabular impact summary which includes the percentage
changes in total regional weekday VMT associated with each of the regional
scenarios.
El. 29
-------
EXHIBIT 19
ILLUSTRATING THE EFFECTS OF TEMPERATURE ON REGIONAL EMISSIONS*
w
?nn <—
I UU
600
BASE 500
REGIONAL
WEEKDAY
HIGHWAY
EMISSIONS 400
IN TONS
FORA
LARGE 300
URBAN 30°
REGION
200
100
n
-
~
-
-
-
-
75°F
32°F
275
250
225
200
175
150
125
100
75
50
25
n
t nnn
-
.
-
-
_
"
-
-
-
75°F
32°F
6,000
5,000
4,000
3,000
2,000
1.000
— n
-
•
-
-
-
-
75°F
32°F
HYDROCARBONS
* Assumes uninterrupted traffic flow conditions.
NITROGEN OXIDES
CARBON MONOXIDE
-------
EXHIBIT 20
COMPARISON OF ESTIMATED REGIONAL IMPACTS OF A CARPOOL/VANPOOL PROGRAM IMPLEMENTED
IN TWO PROTOTYPE REGIONS : MEDIUM SIZE (500,000 -1,000.000 POPULATION RANGE) AND
LARGE (1,000.000 +POPULATION RANGE)
CO
2.0%
1.8%
1.6%
1.4%
1O1/
.2%
PERCENT
REDUCTION 1-°*
IN REGIONAL
WEEKDAY
HIGHWAY °-8*
VALUES
0.6%
0.4%
0.2%
0%
-
-
-
-
_
-
-
.
-1.8
TONS*
M
E
D
1
U
M
-8.3
TONS*
L
A
R
G
E
-0.6
TONS*
M
E
D
1
U
M
-2.8
TONS*
L
A
R
G
E
-1S.O
TONS*
M
E
D
1
U
M
-63.4
TONS*
L
A
R
G
E
-2.6
MILLIOI
GALLON
M
E
D
1
U
M
u -11-6
st MILLION
GALLONSt
L
A
R
G
E
HC EMISSIONS
NOX EMISSIONS
•Estimated absolute weekday regional emissions reductions in tons.
Estimates assume uninterrupted traffic flow conditions.
tEstimated absolute annual regional fuel consumption reduction in gallons.
[Above impact estimates are for Scenario 11 (Medium) and Scenario 12 (Large)i.
CO EMISSIONS
FUEL CONSUMPTION
-------
00
to
2.0%
US
1.6%
PERCENT
CHANGE IN
REGIONAL
WEEKDAY
HIGHWAY
HYDROCARBON
EMISSIONS
<7S°F>
1.2%
1.0%
66%
0.6%
0.4%
0.2%
0%
EXHIBIT 21
ESTIMATED IMPACTS FOR NINE REGIONAL SCENARIOS IN A LARGE URBAN AREA:
REGIONAL HYDROCARBON EMISSIONS
13
TONS*
105
TONS
10.1
TONS
-2.5
TONS
0.3
TONS
2.4
TONS
TONS
• 1
0.7
TONS
n
4.5
TONS
•ESTIMATED ABSOLUTE REGIONAL CHANGE IN HC EMISSIONS
FOR PROTOTYPE URBAN REGION OF APPROXIMATELY 2,500.000 -
3.000.000 SMSA POPULATION AND AN AVERAGE BASE WEEKDAY HC
HIGHWAY EMISSIONS OF 621 TONS (AT 75"F).
Estimates assume uninterrupted traffic flow conditions.
DECREASE INCREASE
'•-1
-------
EXHIBIT 22
ESTIMATED IMPACTS FOR NINE REGIONAL SCENARIOS IN A LARGE URBAN AREA:
REGIONAL NITROGEN OXIDES EMISSIONS
2.0%
1.1%
B
CO
oo
1 $%
1.4%
PERCENT 1.2%
REDUCTION
IN REGIONAL
WEEKDAY
HIGHWAY '•B*
NITROGEN
OXIDES
EMISSIONS ||%
(75°F)
0.6%
0.4%
0.2%
OX
2J
TONS'
_
•
_
-
-
-O.S
3.3 -3.3
TONS TONS
1.9
TONS
-0.5 TONS
TONS °4 °*
1 1 TONS TONS
n n n
I/, III. Iff, lit Jll
?
i.i
jnuc
IliJI/J/fJl/J
I
•ESTIMATED ABSOLUTE REGIONAL CHANGE IN NO EMISSIONS f OR
PROTOTYPE URBAN REGION OF APPROXIMATELY7.5M.OOO 3.000.000
SMSA POPULATION AND AN AVERAGE BASE WEEKDAY NO HIGHWAY
EMISSIONS OF 21S (AT 75 Fl.
Estimates assume uninterrupted traffic flow conditions.
-------
co
2.0% -
1.8% -
1.6% -
1.4% -
1.2% -
PERCENT CHANGE
IN REGIONAL
WEEKDAY HIGHWAY 1.0%
CARBON MONOXIDE
EMISSIONS
"5°rl 0.8%
O.SX -
0.4%
0.2% -
EXHIBIT 23
ESTIMATED IMPACTS FOR NINE REGIONAL SCENARIOS IN A LARGE URBAN AREA:
REGIONAL CARBON MONOXIDE EMISSIONS
•ESTIMATED ABSOLUTE REGIONAL CHANGE IN CO EMISSIONS FOR
PROTOTYPE URBAN REGION OF APPROXIMATELY 2.500,000 3.000.000
SMSA POPULATION AND AN AVERAGE BASE WEEKDAY CO HIGHWAY EMISSIONS
OF 4.IH TONS (AT 7S"F)
Estimates assume uninterrupted traffic flow conditions.
DECREASE INCREASE
' 1
-------
congestion on remaining non-reserved lanes) more than counteracts the ef-
fects of the overall reduction in total VMT associated with these strategies.
This is particularly true for the reserved lane scenarios in which only mod-
est travel impacts are assumed. Under these circumstances, the congestion
caused by removing a lane for exclusive use of buses or buses and carpools
is reduced only slightly by the assumed modest shift from autos to preferen-
tially treated high occupancy vehicles.
These prototype emission results again demonstrate the importance of
initial travel and congestion conditions, highway facility design, and the rel-
ative magnitude of the induced modal shifts in determining the size and even
direction of air quality impacts of corridor-related actions. These strat-
gies can be effective, but the selection, design, and implementation of such
corridor or facility oriented actions must be carefully planned on a case-
by-case basis in light of the above considerations to avoid ineffective or
counterproductive air quality measures.
The dispersed nature of the VMT reductions associated with employer-
based car pool/vanpool programs makes congestion impacts of regional
significance unlikely. Thus, areawide carpool/vanpool programs can be
expected to have emission impacts more consistently in line with overall
regional VMT reductions. In designing and implementing such programs,
the major concern should be to focus on those employers and employment
concentrations which are not adequately served by public transportation.
Regional Fuel Consumption Impacts
Exhibit 24 presents the percentage changes in weekday highway fuel con-
sumption estimated for each of the nine large city regional scenarios. All
of the impacts are reductions, but they tend to be smaller reductions on a
percentage basis than the corresponding VMT reductions (see Exhibit 28).
This is again the result of congestion effects and the difference between the
assumed average speed/facility type/vehicle type distribution of total re-
gional VMT and the subset of regional VMT affected by the scenario strat-
egy. However, the differences between percentage regional fuel consump-
tion and VMT impacts are not as pronounced as for HC and CO emissions
because of a somewhat lesser sensitivity of fuel consumption rates to speed.
Exhibit 24 also indicates the absolute annual reduction in regional highway
fuel consumption in millions of gallons for each of the large prototype re-
gional scenarios.
Table A. 5 for a discussion of the travel impact methodology used to
estimate VMT changes and average speed shifts associated with congestion
for the regional scenarios.
HI. 35
-------
EXHIBIT 24
ESTIMATED IMPACTS FOR NINE REGIONAL SCENARIOS IN A LARGE URBAN AREA:
REGIONAL HIGHWAY FUEL CONSUMPTION
2.0X
1JX
PERCENT
REDUCTION
IN REGIONAL
WEEKDAY
HIGHWAY
FUEL
CONSUMPTION
00
05
O.SX
0.4X
«JX
14.1
UILLION
6ALIONS
14J
MILLION
GALLONS
-11. (
MILLION
GALLONS*
•7.2
MILLION
GALLONS
-2.7
MILLION
•1.5 GALLONS
MILLION
GALLONS
•2J
MILLION
.jg GALLONS
MILLION
GALLONS
n
7.3
MILLION
GALLONS
'f/f^/fi «/*/ «/'
* ' A5* /*•» A
•ESTIMATED ABSOLUTE REGIONAL CHANGE IN ANNUAL HIGHWAY FUEL CONSUMPTION FOR
PROTOTYPE URBAN REGION OF APPROXIMATELY 2.500.000 3.000,000 SMSA POPULATION
AND A BASE AMMAL HIGHWAY FUEL CONSUMPTION OF 1.301 MILLION GALLONS (FULL 366
DAYS. INCLUDING WEEKENDS AND HOLIDAYS).
-------
Capital and Operating Costs
Exhibit 25 presents the estimated capital and annual operating costs for
the regional scenarios. Appendix B presents the unit costs used in the de-
velopment of the capital and annual costs.
The costs for the regional scenarios represent order of magnitude esti-
mates. The development of detailed cost estimates was beyond the scope
of the project. The capital and operating costs for the regional scenarios
assume that some economies of scale would result from implementing re-
served lanes, ramp metering, bus by-pass ramps, and expanded express
bus service in multiple corridors within a large urban area. In this regard,
the unit costs presented in Appendix B were reduced by 25 percent in esti-
mating the capital and operating costs of the regional scenarios.
With the exception of scenarios 11 and 12, the largest individual cost
item for all of the scenarios is for improvements to express bus service.
Generally, the geographic coverage and the frequency of express bus service
were assumed to increase significantly in order to complement the reserved
HOV lanes and divert potentially large numbers of auto travelers. The an-
nual cost of bus service shown in Exhibit 25 represents the incremental cost
of providing bus service above that assumed in the base case (i. e., "before"
case). As for the localized scenarios, the costs of implementing ramp me-
tering and park-and-ride facilities also are significant.
Based on express bus operations in Minneapolis and Seattle, annual oper-
ating revenues may cover approximately 50 percent to 66 percent of annual
operating and maintenance costs of express bus service presented in Exhibit
25. Sizeable annual operating subsidies may thus be needed to operate the
assumed express bus services. Subsidy levels may be more significant if
reduced fare programs are implemented.
Economic Impacts
The economic impacts of the regional scenarios are likely to be small.
The nature and magnitude of the impacts are likely to be similar to those
cited for the localized scenarios on page HI. 22.
ILL 37
-------
EXHIBIT 25
CAPITAL AND ANNUAL OPERATING AND MAINTENANCE COSTS
FOR REGIONAL SCENARIOS
PROTOTYPE SCENARIO
ID No.
11
12
13
14
15
16
17
18
19
20
TITLE
Carpool/Vanpool Program,
Medium Size City; Favorable
Impacts
Carpool/Vanpool Program,
Large City; Favorable Im-
pacts
Reserved Bus/Pool Lanes,
Ramp Metering and Bus
By-Pass Lanes on All Ap-
propriate Freeways;
Modest Impacts
Reserved Bus/Pool Lanes,
Ramp Metering, and Bus
By-Pass Lanes on All Ap-
propriate Freeways; Fa-
vorable Impacts
Reserved Median Lane for
Express Buses on Appro-
priate Radial Arterials;
Modest Impacts
Reserved Median Lane for
Express Buses on Appro-
priate Radial Arterials;
Favorable Impacts
Carpool/Vanpool Program
and Freeway Reserved Lanes;
Modest Impacts
Carpool/Vanpool Program
and Freeway Reserved Lanes;
Favorable Impacts
Carpool/Vanpool Program,
Reserved Lanes, Ramp
Metering, and Bus By-Pass
Lanes; Modest Impacts
Carpool/Vanpool Program
Reserved Lanes, Ramp
Metering, and Bus By-Pass
Lanes; Favorable Impacts
Costs (in Thousands of 1976 Dollars)
ITEM
Carpool Program*
Carpool Program*
Ramp Metering
Reserved Lane
Bus By-Pass Ramps
Express Bus Service
Park and Ride Lots
Ramp Metering
Reserved Lane
Bus By-Pass Ramps
Express Bus Service
Park and Ride Lots
Reserved Median Lanes
Express Bus Service
Park and Ride Lots
Reserved Median Lanes
Express Bus Service
Park and Ride Lots
Carpool Program
Reserved Lanes
Express Bus Service
Park and Ride Lots
Carpool Program
Reserved Lanes
Express Bus Service
Park and Ride Lots
Carpool Program
Ramp Metering
Reserved Lane
Bus By-Pass Ramps
Express Bus Service
Park and Ride Lots
Carpool Program
Ramp Metering
Reserved Lane
Bus By-Pass Ramps
Express Bus Service
Park and Ride Lots
CAPITAL
3,402
300
1,380
9,504
0/4.860
14,586/19,446
3,402
300
1,380
13,662
0/4.860
18,744/23,604
7,088
11,781
0/2.835
18,869/21,704
7,088
11,781
0/2,835
18,869/21,704
300
9,504
0/4.860
9,804/14,664
300
10,890
0/4,860
11,190/16,050
3,402
300
1,380
9,504
0/4,860
14.586/19.446
3^402
300
1,380
13,662
0/4,860
18,744/23,604
ANNUAL OPERATING
AND MAINTENANCE
$ 76
404
252
660
3l97
744
5,253
252
660
5,142
744
6,798
152
5,402
430
5,984
152
5,402
430
5,984
404
660
3,600
744
5,408
404
660
4,113
744
5,921
404
252
660
3,597
744
5,957
404
252
660
5,142
744
7,202
III. 38
-------
IV. SUMMARY AND ASSESSMENT OF SCENARIOS
This section summarizes and assesses the major impacts and the cost-
effectiveness of the localized and regional scenarios analyzed in Section III.
In addition, guidelines are presented for estimating the air quality and emis-
sion impacts of the transportation actions examined in this project. Impor-
tant factors which may affect the transferability of the project's findings to
specific locations are also discussed.
LOCALIZED SCENARIOS
Exhibit 26 summarizes the following impacts of the localized scenarios:
. impacts on peak hour vehicle volumes on affected highway facilipies;
. impacts on peak hour CO concentrations for both typical, good and
typical, poor dispersion conditions; and
. the capital and annual operating and maintenance costs of the sce-
narios.
The freeway-based scenarios (i.e., scenarios 1-8) are likely to achieve
reductions in overall peak hour corridor traffic volumes ranging between 1.5
percent and 7 percent. As illustrated below, the estimated reductions in peak
direction peak hour traffic volumes on the freeways in these scenarios can be
substantial if anticipated shifts to carpooling and transit are achieved.
Percent Reduction in Peak Direction
Scenario Peak Hour Freeway Vehicle Volumes1
1 3.2
2 13.7
3 6.7
4 N.A.
5 14.6
6 3.8
7 8.4
8 8.4
1These values are taken from the travel impact summary, Exhibit 10, appear-
ing in Section III.
'Because of the breakdown in freeway flow projected in scenario 4, it is not
meaningful to report a change in peak hour volume.
IV. 1
-------
EXHIBIT 26
SUMMARY OF ESTIMATED IMPACTS FOR THE LOCALIZED PROTOTYPE SCENARIOS
to
PROTOTYPE SCENARIO
ID
No.
1
2
3
4
5
6
7
1
9
10
BRIEF TITLE
Expanded Express Bus Service in Mixed
Freeway Traffic; Favorable Impacts
Freeway Lene Reserved for Busus and
Carpools; Favorable Impacts
Ramp Metering and Bus By Pass Lanes;
Favorable Impacts
Reserved Bus/Pool Lane, Ramp Meter-
ing, and But By-Pass Lanes; Modest
Impacts
Reserved Bus/Pool Lane, Ramp Meter
ing. and Bus By-Pass lanes; Favorable
Impacu
Contraflow Freeway Lane Reserved
for Buses; Favorable Impacts
Contraflow Bus Lane, Expanded Ex
press Bus Service, and Park and Ride
Lots; Favorable Impacts
Contraflow Bus Lane, Expanded Ex-
press Bus Service, and Lots; Assum-
ing 70X/30X Directional Split;
Favorable Impacts
Reserved Arterial Median Lane for
Express Buses; Favorable Impacts
Contraflow Curb Lane for Local
Buses on Pair of One-Way Arterials;
Favorable Impacts. Unbound
Arterial/Outbound Arterial)
IMPACT ON A.M. PEAK
HOUR CORRIDOR
VEHICLE VOLUME-
BASE PEAK
HOUR
VOLUME
19.667
19.667
19.667
19.667
19,667
14.760
14,750
13.500
3,750
5,000
PERCENT
CHANGE
-I.47X
-6.311%
-306%
-3.97%1 *
-6.98%
-169%
-3.72V.
-4.07%
-15.47X
-4.40%
IMPACT ON AM PEAK HOUR CO
CONCENTRATIONS IN/V'' AT REFERENCE
RECEPTOR. FROM AFFECTED FACILITY EMISSIONS"
TYPICAL. GOOD
DISPERSIONt
BASE VALUE
5,756
6,756
b.756
S.756
5.756
4.798
4.791
4.066
4.964
3,992^-^'
^^3.349
CHANGE
-139
-554
-381
N.A.*
-603
*226
tlOO
-115
-779
-532^-"''
^-^365
TYPICAL. POOR
DISPERSIONt
BASE VALUE
1.210
1.210
1,210
1.210
8.218
6.759
6,769
6.748
6.485
4.992^-^
^>
3.720/6.350
5.224/6.844
4.862/6.482
6,241/7.868
162
3.668/5.218
3.668/5.288
3.694/4.134
461
OPERATING'*'
(PER YEAR)
1.447
1.839
1.703
1.751
2.266
541
1.818
1.818
1,130
123
"On all highway labilities explicitly included in the analysis of the prototype corridor (see diagrams in Exhibit_!_); in both directions.
Volume is for freeway and/or arterial segments approximately 1 mile out fiom the CBD (adjacent to the CBD in the case of Scenario 10).
"CO concentration 50 feet from downwind edge ol piimary corridor facility, based on vehicular ernuaoos from affected facilities only;
uninterrupted traffic flew conditions are also assumed. Maximum 8 hour inngi CO concentrations may be approximated using the procedure in Exhibit 14.
t See Exhibit _IL_ for a tabular description of these meteorological conditions.
t'Ttm value includes the vehicles uriijinally using ibe conidor Ireeway, but estimated as being unable to pass through during peali hour
because of flow breakdown caused by congestion.
S>CO Concentration impacts lor Scenario 4 could not be reliably estimated. See Exhibit iiL and text for further explanation.
I8; Represents incremental opeiallng costs
(b The two capital cost entries represent the lange in costs depending upon whether existing parking
facilities (e.g., snapping center) or newly constructed facilities are required for park-and-ride lots.
-------
The arterial scenarios analyzed (scenarios 9 and 10) also can promote
percentage reductions in peak hour vehicular volumes ranging between 4
percent and 15 percent. As is true for the freeway scenarios, the attain-
ment of such reductions is highly dependent upon the specific setting in
which such strategies may be implemented. However, the percentage re-
ductions in vehicular volumes for arterials are based on smaller base vol-
umes and are not fully comparable to the corridor volumes in the freeway
scenarios.
Generally the relative reductions in peak hour CO concentrations (under
typical, good dispersion conditions) shown in Exhibit 26 are several percent-
age points higher than the corresponding reductions in peak hour corridor
vehicle volumes, but are generally several percentage points lower than the
corresponding reductions in peak direction freeway vehicle volumes. In sce-
narios 4, 6, and 7, CO concentrations are estimated to increase relative to
the base conditions. Although the scenarios are illustrative in nature, the
estimated increase in CO concentrations clearly indicates that careful analy-
sis of alternative tactics on a case-by-case basis is necessary.
Both the capital and annual operating and maintenance costs of the local-
ized scenarios are sizeable. As discussed in Section III, the costs of pur-
chasing and operating new buses for express bus service represent a sub-
stantial part of the total cost of the scenarios.
The potential cost-effectiveness (expressed in terms of ug/m3 reduction
of CO concentration per $1,000 of annualized cost) of the localized scenarios
in reducing CO concentrations is illustrated in Exhibit 27. The annualized
costs in this exhibit represent the sum of annual operating and maintenance
costs and an annualized capital cost. Transit and non-transit capital costs
were annualized using an eight percent interest rate and economic lives
of 12 and 20 years, respectively. Exhibit 27 illustrates that the cost-ef-
fectiveness of the freeway strategies in reducing CO concentrations is
highly variable. Scenarios 6 and 7 which involve the application of contra-
flow reserved lanes for buses along with complementary transportation ac-
tions are clearly not cost-effective in terms of their air quality impacts
based on the scenarios assumed in the project. Scenario 8 (which is iden-
tical to scenario 7 except that a 70%/30% rather than 60%/40% split of
traffic volumes in the peak/off-peak directions of travel is assumed) is
estimated to result in a reduction rather than an increase in CO concen-
trations. This suggests that scenarios 6 and 7 could promote reductions
in CO concentrations under more suitable traffic conditions such as those
assumed in scenario 8.
IV. 3
-------
EXHIBIT 27
COMPARISON OF LOCALIZED SCENARIOS
ON COST AND CO CONCENTRATION IMPACTS
GO
o
oc
Ul
o
o
CJ
o
o
C9
-800
-700
-600
-500
-400
-300
-200
-100
+100
+200
+300
• 9 (ARTERIAL)
5 (WITH FLOW FREEWAY)
• 10 (ARTERIAL)
2 (WITH FLOW FREEWAY)
3 (WITH FLOW FREEWAY)
CO REDUCTION
1 (EXPRESS BUS * 8 (CONTRA-FLOW FREEWAY)
EXPANSION)
• 7 (CONTRA-FLOW FREEWAY)
CO INCREASE
S (CONTRA-FLOW FREEWAY)
-l-
1,000 2,000
ANNUALIZED COST (IN THOUSANDS OF 1976 DOLLARS)
3,000
3.SOO
-------
Exhibit 27 shows that, using scenario 1 as a "minimum action plan" base,
scenario 2 produces a larger incremental reduction in CO concentrations than
does scenario 3 for essentially the same incremental cost. The cost-effective-
ness plot also shows that compared to scenario 2, scenario 5 is significantly
more costly but yields only a marginal reduction in CO concentrations.
The cost-effectiveness analysis is primarily intended to illustrate the
potential air quality improvements achieved per dollar of investment. Such
a consideration is clearly important because of limited government financial
resources available to improve air quality. However, it is important to
recognize other potentially desirable impacts of these strategies in an evalu-
ation process. Strategies incorporating transit improvements can maintain
or enhance mobility when disincentives are applied to discourage travel by
low-occupancy vehicles. Many of the strategies can yield significant travel
time savings to travelers receiving priority treatment and can promote size-
able reductions in peak period vehicular traffic.
The rankings of strategies illustrated by Exhibits 26 and 27 reflect the
transportation measures and characteristics assumed for each scenario in
this analysis. This ranking, as well as the impacts for a given strategy,
could be considerably different within a given urban area because of "local
conditions. " Major factors likely to influence the relative ordering between
strategies and within a single class of strategies include:
. the characteristics (e.g., miles of reserved HOV lane, access/
egress operations, type of transit service, enforcement, size
and location of park and ride lots) of the transportation measures
incorporated in the scenarios;
. the estimated level of transit ridership and ride-sharing increases
which can vary substantially for similar projects as noted in Section
II;
. the capital and operating costs of the strategies which are highly
dependent on the physical and operating characteristics of an ur-
ban area's transportation system and local labor costs; and
. the prevailing meteorological conditions, traffic enforcement pro-
cedures, and levels of service (e.g., operating speeds and v/c
ratios) on highways which are candidates for the types of scenarios
analyzed.
In addition to the potentially large variation in impacts between dif-
ferent packages of transportation measures, considerably different mag-
nitudes of impacts may result from implementing the same package of
IV. 5
-------
actions under different circumstances in urban areas. This possibility
is suggested by the literature review in Section II and may change the
relative ranking of scenarios analyzed in this report.
REGIONAL SCENARIOS
The VMT, emission, fuel consumption, and cost impacts of the ten region-
al TSM programs are summarized in Exhibit 28. Reductions in total regional
VMT in the range of 1. 0 to 1.9 percent are attributable to scenarios 11, 12,
and 17 through 20 which involve carpool and vanpool programs focusing on
large employers. These reductions correspond to reductions of 3 to 6.5
percent in weekday work trip VMT. This represents a substantial shift
of low occupancy auto trips to transit, carpools, and vanpools during peak
travel periods, which will reduce congestion and conserve energy as shown
in Exhibit 28. These same scenarios also are estimated to yield the largest
reductions in regional HC, NOx, and CO emissions.
Scenarios 13 through 17, which involve the implementation of reserved
lanes on multiple radial freeways or arterials in a region, generally resulted
in total regional and work trip VMT reductions of less than 0.5 percent and
1. 5 percent, respectively. The small reductions in VMT are in large part re-
lated to the limited size of the peak period radially-oriented CBD travel mar-
ket in most large urban areas. For example, home to work trips and VMT
comprise approximately 20 percent and 30 percent of total weekday regional
person trips and VMT, respectively. Travel survey data suggests that only
15 percent of home to work trips are oriented to the CBD of urban areas ex-
ceeding 1 million population. However, those urban areas with especially
large percentages of CBD-oriented travel could experience higher reductions
in VMT than those estimated in this study.
Despite their limitations in reducing regional air pollution emissions, the
freeway reserved lane strategies show considerable potential for reducing
peak period travel congestion along radial travel corridors when applied under
appropriate travel conditions. These strategies can contribute to reductions
in CO concentrations along heavily traveled freeways and can also contribute
to reductions of vehicular travel within CBD's.
Exhibit 29 illustrates (using HC emissions) that scenarios 11 and 12, which
involve major employer carpool and vanpool programs, are particularly cost-
effective in reducing regional air pollution emissions. Scenarios 13 through
17 which incorporate express bus service and reserved freeway or arterial
lanes in multiple corridors are less cost-effective than scenario 12 in reducing
HC emissions. The combination of carpool and vanpool programs with express
IV. 6
-------
EXHIBIT 28
SUMMARY OF ESTIMATED IMPACTS FOR THE REGIONAL PROTOTYPE SCENARIOS
PROTOTYPE SCENARIO
ID
Ho.
II
II
13
14
15
IS
IT
11
»
»
BRIEF TITLE*
Carpoul/Vaopool PtOfCim. Medium
Silt City: Favorable Impacts
Carpool/Vanpool Pio|»m, Lir|i
City; Favorable Impact*
Reserved But/Paul line, Ramp
Metering, and But By Pus lanes an
AM Appropriate Ficcwiyi; Modest
Impacts
Relived Bin/Paul lints. Himp
Metering, in* Bin By PBS lanes on
AH Appropriate Freeways: Favorable
Impacts
Reserved Median Lana lor Express
Buses a* Appropriate Radial Ar-
lariab;Moda«t Impacts
Reserved Median lane lor Express
Buses on Appropriate Radial Ar
terials; Favorakle Impacts
Carpool/Vanpool Program and Free-
way Reserved Lanes; Modest Impacts
Carpool/Vanpool Program and Free-
way Reserved Lanes; Favorable
Impacts
Carpool/Vanpool Program, Reserved
lanes. Ramp Metering, and Bus By-
Pass Lanes; Modest Impacts
Carpool/Vanpool Program, Reserved
Lanes, Ramp Metering, and Bus By-
Pass Lanes; Favorable Impacts
CHANGE IN REGIONAL
WEEKDAY VMT
AS PERCENT
OF TOTAL
VMT
-1.5%
-1.5%
-0.25%
-0.44%
-0.23%
-0.31%
-t.0%
-1.9%
-1.0%
-1.9%
AS PERCENT
OF WORK
TRIP VMT
-6.0%
-5.0%
-0.1%
-1.5%
-0.1%
-1.3%
-3.3%
-4.3%
-3.3%
-6.5%
CHANGE IN REGIONAL WEEKDAY
HIGHWAY EMISSIONS IN TONSt
HC
-1.1'
-1.3
-0.3
-2.5
+2.1
-0.7
-2.4
-10.5
- 4.5
-10.9
NOX
-0.0*
-2.1
-0.5
-0.4
-0.4
-0.6
-1.9
-3.3
-1.6
-3.3
CO
-15.0-
-63.4
+ 2.6
-17.9
+37.2
+ 5.1
-29.1
-11.1
-29.0
-63.9
CHANGE IN
ANNUAL
HIGHWAY
FUEL
CONSUMPTION
IN MILLIONS
OF GALLONS
-2.6'
-11.6
- 1.5
-2.7
- 1.6
- 2.9
- 7.2
-14.1
-7.3
-14.2
PROGRAM COSTS IN 1976
DOLLARS (»1,000(
CAPITAL
(ONE-TIME,
IMPLEMENT A-
TIONI
-
-
14.566/10.446
16,744/23.664
16.966/21.704
16.966/21.704
9,604/14.664
11.190/16.050
14.566/19.446
19.744/23.604
INCREMENTAL
OPERATING
1 PER YEAR)
76
404
5.253
6.796
5.964
6.904
5.406
5.921
5.957
7.202
•Al scenarios except #11 are lor a "large" city (1.000,000 * SMSA population). Scenario 11 b set in a "medium site" city (500.000 • 1,000.000 SMSA population).
1 Estimated at 76°F assuming uuMUrnipUd traffic flow conditions.
-------
n
to
EXHIBIT 29
COMPARISON OF REGIONAL SCENARIOS ON COST AND REGIONAL EMISSIONS IMPACTS
t (CARPOOUVAHPfflOL. LARGE AREA)
12
(CAHPOOL/VANPOOl AMD
MULTIPLE CORRIDOR FREEWAY)
« (CARPOOL/VANPOOL AND
MULTIPLE CORRIDOR FREEWAY)
00
EMISSION REDUCTION
(CAHPOOL/VANPOOL.
MEDIUM AREA)
17
(CARPOOL/VANPOOL AND •
MULTIPLE CORRIDOR FREEWAY)
II
• (CARPOOL/VANPOOL MULTIPLE
CORRIDOR FREEWAY)
, 14 MULTIPLE CORRIDOR
FREEWAY)
.13
If .(MULTIPLE CORRIDOR
• ARTERIALS)
(2)
(4)
EMISSION INCREASE
(MULTIPLE CORRIDOR FREEWAY)
• If MULTIPLE CORRIDOR
ARTERIALS)
HMD
3000 4000 fON fOOO
ANNAULIZED COST (IN THOUSANDS OF 1171 DOLLARS)
7000
1000
10.000
-------
bus service/reserved lane strategies in scenarios 18 and 20 are estimated to
result in larger reductions in HC emissions than Scenario 12 but for a signifi-
cantly larger annualized cost. Transit capital and operating costs comprise
a significant percentage of the total cost of scenarios 12 through 20.
As discussed for the localized scenarios on page IV. 5, the cost-effec-
tiveness analysis is primarily intended to illustrate the potential air quality
improvements achieved per dollar of investment. However; a thorough
evaluation should account for the transportation, energy conservation, and
other potentially beneficial impacts of regional-type scenarios discussed in
this section.
The magnitudes of the impacts for each class of regional scenario, and
consequently the ranking between scenarios for a given urban area, could
vary from those determined in this report. Important factors which may
have a major impact in the relative ranking of the scenarios include: the
specific transportation measures packaged in the scenarios, the estimated
types and levels of travel impact, and the costs of implementing and oper-
ating the proposed scenarios.
GUIDELINES FOR AIR QUALITY ANALYSES
Interpretation of Findings
The report is intended to provide information to assist urban areas cov-
ered by EPA's Transportation Planning Guidelines:
. assessing the applicability and potential of the four classes of
transportation programs described above for improving localized
and regional air quality;
. estimating and evaluating the cost-effectiveness of such pro-
grams and their related travel, energy consumption, cost,
and economic impact; and
. identifying key factors (e.g., meteorological conditions, vehi-
cle type distributions and vehicle operating speeds) likely to
affect air quality and air pollution emissions.
The above issues are addressed at a sketch planning scale of analysis.
IV. 9
-------
The report illustrates the magnitude and types of air quality, emission,
travel, fuel consumption, and cost impacts that could result from the imple-
mentation of selected transportation actions in settings similar to those
described for the 10 localized and 10 regional scenarios. The reader should
note that the impact estimates developed in the project are scenario-specific
and great care must be taken in attempting to directly apply the results of
this analysis to specific real-world circumstances.
For example, the increase in CO concentrations in several contra-flow
reserved freeway lane scenarios reflects the travel and meteorological con-
ditions assumed in those scenarios. The results do not indicate that contra-
flow lanes, per se, have undesirable air quality effects, but rather illustrate
the importance of carefully analyzing the potential air quality effects of imple-
menting a contra-flow lane on freeways carrying heavy traffic volumes in the
"off-peak" direction.
The impacts presented in this report also reflect assumed "modest" and
"favorable" travel impacts based on the findings of the literature review in
Section II. The travel impact estimates are considered to be reasonable,
particularly in light of the wide range in travel impacts which have been
observed in demonstration projects for given classes of transportation
actions. However, substantially different travel impacts could occur in a
specific application, depending upon the characteristics of the project under
consideration.
The application of tactics such as pricing incentives/disincentives, auto
restricted zones, area licensing, and parking, pricing and supply controls
in conjunction with the reserved lane, carpool, vanpool, and related sce-
nario tactics has not been examined in the projects. Such tactics offer con-
siderable promise for achieving more significant reductions in VMT than
those estimated in this project.
Factors Affecting Air Quality and Emissions
Important factors
sion impacts include:
Important factors affecting transportation-related air quality and emis-
It is important to point out that contributions to air pollution levels from
non-transportation sources can be quite substantial and vary considerably
in importance from area to area. In order to accurately interpret the sig-
nificance of projected transportation-related air quality impacts, local
planners must also consider the non-transportation sources of air pollu-
tion in their areas.
IV.10
-------
. meteorological conditions (e.g., temperature, wind direction
and speed, stability class and mixing depth);
. transportation facility, vehicle capacity and geometric charac-
teristics (e.g., elevated, at-grade);
. existing and projected vehicle operating speeds, directional
splits of travel, vehicle mixes (e.g., age and vehicle type),
and the modal splits on the affected transportation facilities
and in the region;
. relative amount of VMT and/or vehicles operating in cold
start, stabilized, and hot start operating conditions; and
. development characteristics (e.g., building heights) adjacent
to transportation facilities.
The above list includes data not typically compiled and used for either
short-range or long-range urban transportation planning. It is especially
important to recognize that a thorough analysis of localized transportation
strategies will require the use of corridor and link specific information
in estimating CO concentrations. MPO's and other agencies participating
in air quality planning will have to assess the need for revised analysis
and data collection programs to support their air quality planning process.
The development of a program to monitor the effectiveness of trans-
portation actions in improving air quality is required by the Planning
Process Guidelines. Such a program would be useful to ensure that im-
plemented short range and long-range transportation improvements
are achieving desired improvements in air quality.
The effect of increasingly stringent vehicle emission standards coupled
with the growth in compact car ownership will contribute to reducing total
tons of HC, NOX and CO emissions over time. These are important devel-
opments which states and MPO's must account for in estimating 1982 emis-
sions and air quality for updates to the State Implementation Plans required
by the Clean Air Act Amendments for 1977.
Although these trends have not been quantatively analyzed in this project,
their effects can be estimated using EPA's mobile source emission factors
which reflect legislative requirements for future vehicle emission rates, by
vehicle type.
IV.11
-------
Selection of TSM Actions for Analysis
The analysis of the prototype localized and regional scenarios demon-
strates the need to clearly define the geographic scale of the air quality
problems facing an urban area. The selection of transportation measures
for analysis should be consistent with the scale of the area's air quality
problems. Many measures, such as reserved HOV lanes, are particularly
applicable to alleviating localized air quality problems while other tactics,
such as carpool and vanpool programs, are appropriate for addressing
regional air quality problems.
For example, the results of the regional scenarios illustrate that the
application of the HOV freeway or arterial lanes on multiple radial high-
ways was substantially less effective in reducing regional air pollution
emissions than the carpool/vanpool programs. However, these same
strategies were considerably more effective in reducing CO concentra-
tions adjacent to applicable freeways and arterials.
IV.12
-------
APPENDIX A
ANALYTICAL ASSUMPTIONS AND METHODOLOGY
FOR NON-COST IMPACT ESTIMATES
A.1: Overview of Technical Approach for Air Quality Impacts Analysis
A.2: Basa Trawl Conditions for Localized (Corridor) Prototypes
A.3: Basa Travel Conditions for the Regional Prototypes
A.4: Estimating Travel Shifts for Localized Prototype Scenarios
A.5: Estimating Travel Shifts for Regional Prototype Scenarios
A.6: Estimating Highway Emissions
A.7: Estimating Localized Concentration Impacts
A.8: Estimating Regional Fuel Consumption Impacts
A.9: Illustrative Calculation of Travel Shifts
A.I
-------
TABLE A. 1
OVERVIEW OF TECHNICAL APPROACH FOR AIR QUALITY IMPACTS ANALYSIS
1. PROTOTYPE SCENARIO
SELECTION AND
SPECIFICATION
20 SCENARIOS FOR OETAI
FOR RECENT BASE YEAR!
• Prantypt Rtjion of Apt
•CwiMir/Ficilty D«cri|
II. TRAVEL IMPA
III. EMISSION]
IMPACTS
CTS
BASE YEAR TRANSPORTATION
PLANNING DATA FOR:
•Prautyp* Rtftaa
• SriMM ConMm «r
Hilton FidHlM
1 > '
LEO ANALYSIS DEFINED
N TERMS OF:
atia*
IkniM
tin, II AppliabU
OBS
IMP/
LITI
ERVEO OR MODEL-ESTIMATED TRAVEL
UTS OF CANDIDATE STRATEGIES FROM
RATURE SEARCH:
• Trauft RUinWp
•M^ilSpM
• Vtkid. OiaipMy
• ViMdtVitaMiHVMT
•Aim|> SPM^ «r Trml HIM
ESTIMATE HIGHWAY TRAVEL IMPACTS
FOR EACH SCENARIO
FOR REGIONAL IMPACTS:
•VMTbvA«ra«lS|Mdi«d
RH^Typl
• ViMcfc Typ« OteribrtM
•Tri» L~t* Oboib«iw v
Hat/CuM San Eitimm
T~
HETEOROL06
AND FLEET A!
• AnbiMt TM
H.midity
•WmdmdSn
•OnntfFlMt
Inddwaof
TmhrT(mi
LMd..«B.
ICAL CONDITIONS
(SUMPTIONS:
•ptraotra Mrf
ibility Cooditiom
Mil And
A/C
>1, AddltJMll
FOR CORRIDOR IMPACTS:
• ViMciiptrHnrirtAim*
S|Mri
•VtUdiTypiDlnribMiM
•H«/C*WStmCM«liw
EitiMtn
Al
1
>PLY EPA "MOBILE SOURCE
IISSION FACTORr
1
ESTIMATE HIGHWAY TRAVEL EMISSION IMPACTS
FOR EACH SCENARIO, AS APPLICABLE
CORRIDOR/HIGHWAY FACILITY:
CO (jraro |>W ucood-mi.)
REGION:
• HC(tmn)
•N0« (ton)
•CO(tMH)
IV. LOCALIZED AIR
QUALITY IMPACTS
APPLY EPA HIGHWAY MODEL FOR THE FOLLOWING
REPRESENTATIVE METEOROLOGICAL CONDITIONS:
•TYPICAL. GOOD DISPERSION
•TYPICAL. POOR DISPERSION
•EXTREMELY, POOR DISPERSION
ESTIMATES OF STATEGY-1NDUCED CHANGES IN CO
CONCENTRATIONS FOR REPRESENTATIVE RECEPTOR
SITES SURROUNDING AFFECTED HIGHWAY FACILITIES
A.2
-------
TABLE A.2:
BASE TRAVEL CONDITIONS FOR LOCALIZED (CORRIDOR) PROTOTYPES
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OR SOURCE
COMMENTS
I. GENERAL
A. VEHICLE CAPACITIES
FfwwtyLiM: 1.750 vehicles par hour
Arterial LIM, No Parking: 800 vthidei pw hour
8. AVERAGE SPEEOS
Based M computed volume to capacity ratios.
Assume all segment] in CO impKt ana cm bo eate-
prized a "Fringe" location.
C. BASE VEHICLE VOLUMES
Except MOW otherwise specified, for a.m. pMk hour.
• Inoouad freeways it copocity (V/C • 1.00)
• Win pmnery corridor fieUity, inbound arttriil
near capacity (V/C-0.94)
• Whn competing with fretwey, inbound vtiri*)
below capacity (V/C-0.75)
• Directional split of traffic on ill feenities is 60%
inbound ind 40% outbound. (70%/30% on
fieewey for Scenario 8 only, by assumption.)
0. VEHICLE TYPE DISTRIBUTION
Except for scenarios 9 and 10, a.m. piak boor
vahidt typo percentage distribution:
Vanido Typo
Sinojo ocapant auto
Two occupmt auto
3+ Cwpoot (avo. occ. > 3.8)
Local bus (avo. occ. • 55)
Expms bus (avo. occ. • 45)
Truck
Fraawoy Artoriol
71.0%
18.9%
4.7%
0%
0.4%
5.0%
70.1%
18.7%
4.7%
1.6%
0%
5.0%
E. AVERAGE TRIP TRAVEL TIME
Computed butd on 10 milts tnvtl oo primary
corridor facility, a follows: .5 milo in CBO, 2.5
mHos in frinot sna, 5.5 milos in outlying businats
district, »d 1.5 milts in rtsidantial ana.
Tables 33 and 34. OHracttrhtio of
Urban Transportation Systoms (CUTS
Manual)
TaMts 33 and 34, CUTS Manual and
1965 Highway Capacity Manual
Prototype assumptions
NCHRP Report 143, p. 69
Peat, Manned. MltchtH & Co., Carpoolina
Impact Study. Technical Memo II,
February, 1970
Find Report. I-35W Urban Corridor
Demonstration Project, p. 19-A
Prototype assumptions
Prototype assumptions. Four anas art
Highwey Capacity Manual categories
used to estimate ipted.
At level af service "E"
Speeds for local buses judgmontitly set
based on typical ranges cited in ITE
Transportation and Traffic Engineering
Handbook, p. 218.
Capacity conditions chosen to reflect
realistic peek hour conditions oo radial
highway facilities. Ovet-eapecity hose
conditions rejected as not appropriate
for types of programs to be tested on
these prototypes.
For retotivt distribution of 1 occupant,
2 occupant, and 3+ occupant autos.
For relative distribution of carpools by
number of occupants.
For the relative percent bus.
For the relative percent track, distribu-
tion of corridor bese as between freewey
(express) and arterial (local), and avenoa
bus occupancies.
V/C ratio for CO impact area segment
ind aree type distinctions used to esti-
mate speeds over 4 portions of 10 mde
trip. Travel time estimetes used only to
support assumptions on magnitude of
model shifts which a program can be
expected to cause.
(Continued)
A. 3
-------
TABLE A.2:
(CONTINUATION 1)
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
II. FOR SCENARIO 9 (5 LANE ARTERIAL)
A. VEHICLE TYPE DISTRIBUTION
For a.m. pnk hour
Vehicle Typ«
Single occuptnt auto
Two occupant auto
3+ Carpool (ava. occ. • 3.6)
Local bin («vt. oec. - 55)
Exprtn bus (avi. occ. ' 45)
Truck
70.8%
18.9%
4.7%
0.7%
0%
5.0%
III. FOR SCENARIO 10 (PAIR OF ONE WAY ARTERIALS)
A. VEHICLE TYPE DISTRIBUTION
For J-ro. ptak hoar
Vehicle Typ«
Single occupant auto
Two occupant auto
3+ Carpool (ava. occ. > 3.6)
Local bus (ave, occ. » SO)
Exprass bus (ava. occ. - 45)
Truck
70.1%
18.7%
4.7%
1.3%
0.2%
5.0%
BASIS OR SOURCE
Sima as for 1.0, except:
Attaint no express bus sarvica in
(arterial) corridor bafora program
implemented.
Assuim ralativalY low initial
local twj volume (15 in paak hour,
inbound).
Sama as for I.O, except:
Assuma limitad numbar of axprass
busas (5 in paak hour, inbound).
Assuma 40 inbound paak hour local
busas (tha lowar and of tha 40-60 bus
volume cfted in NCHRP Report 155.
as a warrant for tha proposad type
of curb lana strategy!.
COMMENTS
Changes ara warrantad:
• bacausa this prototype contains no
fratway facility in corridor
• by scenario assumption of relatively
high modal shifts ("favorable" im-
pacts), which would ba impossible
with high initial transit ridarship
On a major 4 lane, one-way arteroU, a
small number of "axprass" busas were
considered reasonable.
Average local bos occupancy was tat at
tha slightly lowar value of 50 to main-
tain initial ridarship at nat to* high a
level (consistent with tha assumption
of moderately favorable impacts) while
satisfying tha minimum bus volume
warrant of 40.
A.4
-------
TABLE A.3:
BASE TRAVEL CONDITIONS FOR THE REGIONAL PROTOTYPES
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
1. GENERAL
A. ASSUMED SPEED BY LEVEL OF SERVICE CLASS
8.
v^li»«lol
^^^Swriei
Rood Typo ^"^-v^
FREEWAY
ARTERIAL
AH but local b«
local OH
LOCAL/COLLECTOR
A
55
35
25
15
B
55
27
20
15
C
SO
22
14
15
0
40
17
to
10
I
13
15
1
5
F
20
8
5
5
ASSUME V/C RATIOS BY LEVEL OF SERVICE
s^ Lwolof
^X. Sinrieo
RoadTypix^
FREEWAY
Assurnid V/C
Aving*
CIissRingi
ARTERIALS
Assumid V/C
Avtrag*
Clta flmgi
A
JO
<.40
.40
< fi
B
.50
.4(K5
.65
S-7
C
.85
B.5e\73
.75
.7-.B
0
E
.71 M
JJ-.82 J2-140
.is as
.I-.9 .9-1.0
F
1.05
140-1.10
1.05
1.0-1.1
II. MEDIUM SIZED REGION
A. BASE REGIONAL WEEKDAY HIGHWAY VMT
(WEEKDAY VMT IN lOOITi)*
ROAD AND VEHICLE TYPE
1
f
«
t
Y
1
T
E
R
1
A
L
AUTO
EXPRESS BUS
( TRUCK
SUBTOTAL
AUTO
LOCAL BUS
TRUCK
SUBTOTAL
Col tctor/Locd (Auto Only)
GRAND TOTAL
VMT
IN 1,000-j
1,992.3
4.7
401.1
2.38B.B
4.79ILB
19.1
9B7.S
5.777.4
1.569.1
9.846.0
PERCENT
OF TOTAL
20.23%
0.05%
4.01%
24.36%
46.66%
0.19%
9.13%
51.68%
16.98%
100.00%
•Thm VMT vilun in furthir distggrtgrad by six Iml of
sink* cinform (A through F) n mdfeiud to thi right
BASIS OR SOURCE
Avtragi ipMdt tantd on intorpolftioiii
of ia*td vriun for thi itittd Itirali of
urvici in tho Hlghmny CiptcrtY
*inu»l, applominttd, by judgmtntll
laumptioni whtrt ntetniry.
Highvnv Ciptertv Minuet. A "piok
hourfiaordsdifiMdinHCMIof
.91 wa utumtd).
Tool VMT Vriur Amngototil
1972 vMokdiy VMT for 26 ngiom
nooning in thi 500,000-1.000.000
populition gnu*. Nitianil Tnni-
Suppltmtnt (NTHI, Tibli 0-1.
Ficilctv Tvpt Oinribution: Uiing
facility typ* dinribution KTUB id
itxirn.
Lml of Sonici Obnibutioii: Umg
umpli hignwoy tnigiiniint mod*) VMT
by LOS nifflimry for AHighiny County
(Pittsburgh). For lool/eollietor rotdi.
irtoriol diminution U«HJ, ixcipt LOS
Vihidi Typi Distribution: SMII n
1.0 in Tibli AJ. For imlyttesl
limpljcity only «itn conadtnd for
collKtor/loal raids.
COMMENTS
Avtnti spndi in ixeta of 55 mph
v«ft not pinnitttd.
Assumtd valid for tnvtl impieti (i.i..
VMT chmgos) is w*ll n bni volumn.
Assumtd nlid far ami imptca is
wtll n bu« (tlucs.
Annuit VMT «ns canvirnd to wmkdiy
VMT with an lonuilizition factor of
339.5
Midium-tizid prototypi ngion initntd
raluis of ntragi of 25 ngioni in
500.000-1,000,000 populition group
(mingi SMSA trnpioymint > 293,590)
Awngi occupmcy of "Auto" whn
tbtn is no bmkdami into accnpncy
subgroups is 1.33.
Sina jumnuftu win milibli only for
24 hour ntngi LOS. i man caagtsnd
cmtral county, yitr 2000 summiry VMS
used to simuliti currmt pnk hour con-
ditions.
VMT tnitrix tehinid by ipplying neh
of tftm dtnributioni to tool VMT using
an indipmdtnco issumption.
A. 5
-------
TABLE A.3
(CONTINUATION 1}
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
III. LARGE REGION
A. BASE REGIONAL WEEKDAY HIGHWAY VMT
(WEEKDAY VMT IN 1000/sl*
ROAD AND VEHICLE TYPE
f
R
W
A
Y
A
R
T
R
1
A
L
AUTO
EXPRESS BUS
TRUCK
SUBTOTAL
AUTO
LOCAL BUS
TRUCK
SUBTOTAL
CollKtor/Local (Auto Only)
GRAND TOTAL
VMT
IN 1,000's
10,219.5
24.2
2.060.9
12.304.8
18,213.1
72.9
3,978.1
21,983.7
9,678.7
43,945.0
PERCENT
OF TOTAL
23.28%
0.06%
4.69%
28.00%
41.4SS
0.17%
8.37%
49.98%
22.02%
100.00%
•Thra VMT vilun art fuithtr diuggngrad by six Iwd of
arvici cmgoriti (A through F), is indicmd to th« right.
BASIS OR SOURCE
Tottl VMT Vilm rod Ficility
Tvai Distribution obttintd as in
II.A of this tibli, but for 23 re-
porting regions in thi 1 ,000,000
+ population rjnoa,
Ltvri of SonriCT Distribution and
Vthidt Typo Ontribution txaetly
a in II.A of this tabla.
COMMENTS
Slim commtnts n for II.A of this tibU,
•xctpt that th< lirgo prototypt rtgio*
nsignod v*hits of mngi of 23 ngioni
in 1,000,000 + population group
(tvaragt SMSA amploymiin *
1,152.786).
A. 6
-------
TABLE A.4:
ESTIMATING TRAVEL SHIFTS FOR LOCALIZED PROTOTYPE SCENARIOS
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OR SOURCE
COMMENTS
I. GENERAL
A. BUS SERVICE EXPANSION
If tb* prototype stntatjy/prearam explicitly include! »
expaatuM of axprea bat service, the best number of exprea
bosas daring the e.m. ptik hour are eaumad to doubl* or in-
crease yitl i "comfonaMo" avenge occupancy of 40 a
achieved at tin flael eo»Jlbriaiii ridtnhip level, whiehtmr«
tkt laraer increase in baatt,
If the prototype strategy/program don not ittelf eaU for
M initial expansion of service, then my increases i* ridonhip
tn awmed to 01 tlnorbtd party by in incmst in average
expraas but occapmcy up to SO >nd partly by an iiKima in
bum ta satisfy the final equilibrium ridenhip at tha highar
occupancy laval.
8. SOURCE OF FREEWAY BUS RIDERSHIP INCREASES
OafinMon of nnmad prototypa bus
larvk* axpandon stratajy.
Stratagy dafinitian.
Rate
nway aipiao bm tanica a unimtn' ta con-
9tt of renn wit* lama (but not ortaniira) local caMactor
anrica in addition to tht dominant fraaway lin
If dia stnttty/profnm axplicrdy indudai an axpamion
of bat larnca, 10% of any ridandrp incraaa> n anumad to
ba pn*iaaaV unmada tripi (inducad traval).
If tha proaiani doat not axplkitry induda an axpaniion
of bn sanica, nona af any ridanhip incraam n asuimad
to coma from pravioady unmada tript
Of tha ramaininj ridanhip incima, tha sourcai an
mumad to ba thita from othar modal a follows:
Sourca of Incraaa
Local (artarial) but
Artarialauta*
Fraaway aatat
Pareant of Panan Trip
20%
16%
64%
Values from similar past experiences:
• 1-95 in Miami: 14% (Service and
Methodsi Oemoimretion Proonrn
Annual Report. UMTA. ISfTl
• Blue Straak service in Seattle: 18%
(Blue Straak But Rapid Transit
Demonstration Project - Final
Report)
Travel impact assumption
Valuat from similar pan axpariancai
for parcant from but:
• I-9S. Miami: <11%
• I-3SW, Mlnnaapolit: 41% (Final
Raport for tha I-35W Urban
Carridor Oamenttration Projact)
• Kalanianoala Hijdway. Hondula:
18% ("Expran Bin Usa in Hona-
lull: a Can Study." Trantporf>
UOB Rasaarch Bicord 686)
For dia parcant from irtarial tnd fraa-
way auto, valuat from tha I-3SW ax-
parianca wara usad.
lowar valua of 10% anumad bacauta:
• thit analysis it for i.m. paak hour
ind not bath paak pariodt durini
which a highar parcant of indocad
trawl would ba likHy
• citad mults ira from survayt which
would yiald soma small parcant of
naw ridart ann if conductad on in
unchanged routa
For parcant from irtarial but, a valua
it tha lowar and of tha nnga (20%)
was chotan sinca tha highar valua for
I-35W (41%) was for a projact in
which naw ixprast but strvica was
provided that had axtansiva collactor
functions, not inumad in tha prato-
typa prograans.
Tha ictaal pareantagas wara normalizad
to sum to tha 80% remaining iftar tha
usumed 20% local bus shirt was
(Continued)
A. 7
-------
TABLE A.4
(CONTINUATION 1)
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OR SOURCE
COMMENTS
•Within tht automobile categories, thifo from 1, 2, and
3+ occupant autos an alloctud in proportion to the
base number of persons in nch category.
tFor shifts from freeway auto to tnmit, nom of thi shift
a isumtd to comt from 3+ occupant autot (carpools)
whan tha strategy/program includes priority tnatmint for
carpools also.
Decreases in local but ridtnhip ara assumad to mult in
dacraasad average local bui occupancy rather than any
decrees** in ajn. paak buses.
C. SOURCE OF FREEWAY CARPOOL INCREASES
Nona of any iocraau in fratway carpools during a.m. paak
hour is assumad to ba asuciatad with previously unmada
trips (inducad travel).
Tha sonrcas of any incraasa in fraaway carpools ara assumad
to ba shifts from other modas as follovn:
Sourea of Incraasa
Artarial carpod
Artarialauto d.Zocc.)*
Fratway auto (1,2 oee.)*
Parent of Parson Trips
10%
18S
72%
*Within tha automobila categories, shifts from 1, 2, and 3+
occupant autos ara allocated in proportion to tha basa
numbar of parsons in each eatafory.
0. SOURCE OF EXPRESS BUS HIOERSHIP INCREASES ON
ARTERIAL WITH RESERVED MEDIAN LANE
Of tha original local bus ridarship on arterial, assume 15%
can make effective use of express bus service introduced
and shift to express bus.
Since there is an expansion of bus service for all stringy/
programs associated with this prototype, assume 10% of
ridership increase is previously unmade trips.
Of the remaining bus ridership increese, all of it comas from
arterial antos, distributed across 1, 2, and 3+ occupant cate-
gories in proportion to the basa number of persons asso-
ciated with each.
The number of new buses introduced for tha a.m. paak hour
which is associated with the introduction of median lane
•xpress bus service is set at that which will yield a very
comfortable average bus occupancy of 35.
(Continued)
Primarily, a travel impact assumption
Assumption
Travel impact assumption.
Assumption
For percent from arterial carpool,
impact assumption.
Tha percants from arterial and free-
way autos, respectively, are based
on the same I-35YV values used in I.B
of this table, but normalized to sum
to 90% instead of 90%.
Seme assumption used for shifts to
transit in 1.8.
Assumption.
Same assumption used in I.B of this
table for fraaway prototypes.
Seme assumption used in I.B of this
able for freeway prototypes.
Definition of prototype strategy/
program.
This assumption is basically consistent
with limited available information from
the Kalanienoatt Highway. Blue Streak,
and 1-95 experiences on auto driver/
passenger or 1 occupent/2-t- occupant
splits.
Not unreasonable, given normal prac-
tice for smell ridership declines.
This value (10%) is one-half of the
arterial tnnsrt-to-fneway shift value
(20%) used above. This is consistent
with the fact that tha arterial per-
centage share (out of the corridor total)
for transit is twice the percentage share
for carpools in tha prototype travel
conditions assumed.
Low occupancy value selected to reflect
a fairly high level of service, designed
to encourage ridership.
I Continued)
A. 8
-------
TABLE A.4
(CONTINUATION 2)
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OR SOURCE
COMMENTS
E. SOURCE OF LOCAL BUS RIOERSHIP INCREASES ON
RESERVED CONTRAFLOW ARTERIAL CURB LANES
Any existing express but ridonMa M facility remains mbli.
Sine* thin it no expansion of bm service associated with tho
retovont itratagy/prognai, none of the local but ridonhlp
increase n assumed to b* previously unmade trips.
AH local bus ridonhip increases com* from nttriol inert,
distributed across 1.2, and 3+ ocpipint categories in
proportion n thi bm nvmbtf of persons associated with
each.
F. CONGESTION DELAYS ANO ROUTE DIVERSIONS
Assumption.
SHIM luumption used in I.B of thn
taMa for fraewey prototypes.
Anumption.
On freewoYS, whm the V/C ratio exceeds 1.1. bmkdown of
flow is presumed. Only 10% of tho traffic in excess of capo-
city divert to parallol arterioli. Tho remaining 90% ovtr
cipority ii assumed to stiU uso tho fnoway, bit bo unable
t» pan through during tho puk hour.
When tho V/C ratio exceeds 1.00 on fnowoyi, continuout
flow can no lonoar bo praniniad. No linjtt lowar mnga
sp«od can aa raliably Btitnad. Thus, tho avtraga tpaad for
V/C * 1.00 it roportad, tooathar with a rough titimata of
stop-and-«o dalay in minutos.
On artariali, whan tha V/C ratio axcaadi 1.1, nsuma ill
traffic in (xetn of 1.1 timn idoal capacrty divom to
attornata trtarial routn (adding an avaraga of ono-half
mila to tha total ono-way trip langth).
Trtv*l impact astumption.
Eitimata of stop-and-go dalay ii band
on a formula idoptad from a queuing
modal delay formula. Saa P. 65 of:
Buidallnot for Travel Oamand Analy-
Tha curb line offan no benefits to either
upreo buses or their current uteri.
Occupancy distribution same as that
assumed in I.O. ibono.
Assumption consistent with frequency
of extreme over-capacity congestion on
some freeways (little dhenion to
artarials).
ses of Proe/am Measures to Promote
irpools. Vanpoah ind Public
ion (Prepared by Cam-
£«
Is
bridge!
1976).
ystematics, Inc. for FEA,
Trent impact assumption.
Diversions from severely congested
irterials an much more profitable and
likely then diversions from freeways.
II. TRAVEL SHIFTS FOR INDIVIDUAL SCENARIOS
A. FREEWAY SCENARIOS
SCENARIO TITLE
1. Expanded Express Bus Service
in Mixed Freeway Traffic;
Favorable Impacts
Freewey Lane Reserved for
Buses and Cirpooh;
Favorable Impacts
INCREASE IN FREEWAY:
BUS HIDERSHIP CARPOOLS
50%
100%
100%
Bus increase; roughly iqual to in-
crease in ridenhip reported for
Seattle Blue Streak experience (sea
I.B of toMe for reference).
Bus increase: Literature search
findings for a similar strategy/pra-
jram in Exhibit ], B: 1182% in-
Daily Blue Streak patronage increased
from 7,530 to 11,189, despite e 3.8%
decrease in overall travel during same
Carpool increase: In Exhibit 3, B,
Carnool i
ilBOKii
increase is reported.
100% chosen insteed of 182% for Santa
Monica experience because of the ex-
tremely low initial fraction transit in
that case.
100% chosen instead of 180% reported;
again, because of the vary low initial
fraction of carpools in that experience.
Both increases are still fairly large, but
consilient with tha assumed initial
modal split for the prototype corridor.
(Continued)
A. 9
-------
TABLE A.4
(CONTINUATION 3)
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OR SOURCE
COMMENTS
SCENARIO TITLE
3. Rimp Metering and But By-
Pin Lanes; Favorable
Impacts
4. Reserved Bui/Pool Lane.
Ramp Metering, ind Bus By-
Pin Lanes: Modest Impacts
5. Reserved Bus/Pool Lim,
Rimp Metering, and Bus By-
Pin Lanes; Favorable Imputs
INCREASE IN FREEWAY
BUS RIDERSHIP CAHPOOLS
100%
75%
125%
50%
95%
6. Cantraflow Freeway Lam
Rn*rv«l for Busts;
Favonblt Impacts
50%
7. Contraflow Bus Lam,
Expanded Express Bus Ser-
vice, and Park-and-Ride
Lots; Favorable Imptcts
12554
Contraflow Bus Lane, Ex-
pindad Strvici, and Lots;
Assuming 70%/30% Oiree-
tional Split; Favorabli
Impacts
125%
(Continued)
But increase: Sat at somewhat
iowaTiavaTthan that achieved in
scanario 7 (125%).
Incnasas wara determined judg-
mentally, to ba lowar than tliosa of
scanario 5 (fnorabla impacts).
Bus increase: Ralalhra to scanario 2
(100%), addition of ramp mataring
and bus by-pan should ineraasa tha
bus tima advantaga and thus tha bus
ridarship increase.
Carpool increase: Cbosan to ba
slighdy smallar than scanario 2
value (100%).
Bus increase: Expariancas reported
in Exhibit 3, A show ridarship in-
creasas of 14-44%. Selection of
larger valua for pratotypa easa (50%)
mada for reasons to right.
Bus incraasa: Chosan to ba graatar
than scanario 2 valua (100%) and
also graatar than tha sum of tha im-
pacts in scenarios 1 and 6, tha con-
stituents of scanario 7 150% * 50% '
100%).
Sama as scanario 7.
Scanario 7 should nava a largar bus
ridarship incnasi bacausa tha but travaf
tima advantjga should ba graatar for tha
contraflow lam stratagy thin tha ramp
matarini and bus by-pan stratagy undar
tha pratotypa conditions.
Although lowar, thasa incraasat still
raflact tha ralativaly graatar impact on
but ridarship than on carpooling
assumad in scanario 5.
Givan limiting factors on maximum bus
ridarship incraasas (commutara with odd
hours, inaccauibla to transit, naading a
car, ate.), a furthar incraasa of 25% ovar
scanario 2 was considarad as larga as
would ba raajonabla.
Smallar -aim results from no incraasa in
incantiva for carpooling but ineraasad
compatition from transit ralativa to
scanario 2.
Expariancas for which information was
available could ba expactad to have much
lowar increases because:
• tha base transit levels in documented
demonstrations wen already vary
high.
• demonstrations were applied primarily
to reduce localized ajn. peak conges-
tion through use of underutilized off-
peak direction capecity.
Increase should ba greater than in sceneno
2b«
• the contraflow bus only line should
provide a graatar time advantage to
buses than a bus/pool line.
• in scenario 7, buses are not competing
against carpools for increases.
Increase should ba graatar than sum of in-
craasas for separata parts of combination
program since tha travel tima, access, and
service area improvements should rein-
force the impacts of each other.
The only difference between scenarios 7
and 8 are in the assumad off-peak direc-
tion vehicle volume on tha freeway.
{Continued)
A. 10
-------
TABLE A.4
(CONTINUATION 4)
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
L ARTERIAL SCENARIOS
SCENARIO TITLE
9.R*s«vid Artirial Madia* LUM
tar Expras Butts: Favoraala
(•pacts
10. Contraflow Curb Lan* for
Loot Bum 01 Pair of Out-
Way Artarials; Fnorabl*
Impact!
RIOERSHIP INCREASE
Expratt bus ridanhip whmtd
wkicb yMdt onrall but modd
split of 40X(lonlpl«.x-
prm).
ISXincnao in local but
ridtrshia an utinils in poik
diracoon.
BASIS OR SOURCE
Chan* to k« grarar thtn 30% bat
modil split Khltvtd in slmMir
projtct an 7th Annul in Mlimi
(Exhibit 4, G).
Judgmental dmiminition.
COMMENTS
Hlfhor but modri split (40%) eh«M n
rafltet fmonWs impict issumptiw
md substntMl (15SI local but mirkn
biso whicfc prototypo corridor stara
with bofon addition of txpraa ionic*.
1 SX valua chosen « rtttonably opti-
rnistk givm modtn sin of poniblo bus
trtotl timi savings, rdttnralv laroa
initial bus modal split, and fact that
most trips will still probably ba fastar by
into for pratotypa casa.
A. 11
-------
TABLE A.5:
ESTIMATING TRAVEL SHIFTS FOR REGIONAL PROTOTYPE SCENARIOS
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OR SOURCE
COMMENTS
I. GENERAL FOR SCENARIOS INVOLVING EMPLOYER
CARPOQL/VANPOOL PROGRAMS
A. OVERALL APPROACH
Since till carpool/venpool programs to be analyzed m em-
ployer based, till VMT impacts will bt estimated on a "per
employee" basis and thin multiplied by assumed regional
employment for tin prototype region to obtain estimated
change in weekday regional VMT. This regional reduction
in VMT will thin bt distributed to livtt of service (avenge
speed) ind rotd-typt categories so thit emission ind fuel
consumption impact] can also b* estimated.
Th« overall changa in VMT consists of two components:
• non-circulatory - associated with tha shift from many
low occupancy vehicles to fawaf high occupincy
vehicles (carpools and vanpools). A reduction result!.
• circulatory - associated with additional vehicle travel
to drive to carpool meeting points and for picking up
or dropping off non-driving pool members. An in-
crease in VMT results.
8. NON-CIRCULATORY VMT REDUCTION
The regional vnekdey change in non-circulatory VMT
associated with carpool/vanpool programs is estimated
by multiplying regional employment by an average VMT
saving per employee associeted with the program.
The per employee VMT saving factor is based on the
assumed program participation rates; the change in
vehicle occupancies associated with the shift to carpools
and vanpools; and the average work trip lengths involved.
The values assumed in estimating the non-circulatory VMT
changa associated with areawide employer carpool/vanpool
programs are as follows:
Adopted from analytical approach
appearing in: Frederick Wagner,
"Evaluation of Carpool Demonstration
Projects" (Paper presented at Annual
Meeting of the Federally Coordinated
Program of Reseerch and Development
in Highway Transportation, Columbus,
Ohio, Mov. 8,1377).
QUANTITY
Regional em-
ployment
Avenge work
trip length
among those
forming carpools
VALUE ASSUMED FOR ANALYSIS
MEDIUM SIZED REGION LARGE REGION
293,990
12 miles
1,152,766
16 miles
1970 U.S. Census Journey to Work
data
Medium: Exhibit 5, A2 reports
range of 8.8-18.5. Average value
for reported regions with appro-
priate populations in paper by
Frederick Wagner is 11.11.
Large: Exhibit 5, A1 reports range
of 6.3-22.3. Avenge for large
cities in Wagner paper is 15.28
Average number of SMSA workers in 28
regions in 500,000-1,000,000 population
dan (medium) and in the 23 regions in
1,000,000 + population group (large)
reporting VMT for the National Trans-
portation Study, respectively.
Chosan value of 12 is dose to middle of
reported range and slightly larger than
average in Wagner peper, consistent with
typical "favorable impact" assumption.
Chosen value reflects same guidelines as
used for medium size region.
(Continued)
A. 12
-------
TABLE A.5
(CONTINUATION 1)
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OH SOURCE
COMMENTS
VALUE ASSUMED FOR ANALYSIS
MEDIUM 5IZEO REGION LARGE REGION
Avw*|i work
trip length
MI M| than
farming
nepeoh
Avenge carpaol
vthida octuiMMy
Avenge veapool
vehicle occupancy
Avenge ovtrall
commuter
vehicle occupancy
25 miles
3.1
2SmHn
2.9
11
1.25
1.20
Carpool participation
nn; estimated num-
ber of im» carport
members per regional
employee as i mult
of prognm
0.0273
0.02SS
(Continued)
Exhibit S. C (•pom rang* of 1S-3S
miles. No distinction based on
region sin.
Medium; Exhibit 5. A2 rtpora
range of 2.9-3.3.
Liroi: Wegner paper riports i 2.30-
3.02 nngo with 12.8 ntragi.
Exhibit S, C suggests in wtrtgo of
•bout 11.
Modium: Exhibit S. A2 reports
nngo of 1.0-1.1. Wignirptptr
yMdi avenge of 1.29.
Large: Exhibit S. A1 npom rengi
on.l4-1.4Z. Wagner popor yields
wing* of 1.23.
Mtdium: (See natnion to right)
X chasm is 0.022 from range of
.017-.024 nport(d in Exhibit 5, A2.
Y choson n 0.40 from nngo of .17-
.54 nporttd in Exhibit 5, A2. Somo-
wbn higher thtn titimoti for
SMnmomo thit 33X of imploytti
in of imployin of 200 or man
(Pon, Mirwick, Mltthtll & Co. Cir-
pooling Impoct Study).
CPOCC is ibovt.
Ljroi; X diostn is 0M from nngi
of .013-.074 (cluftind man towird
lowor »nd) nporttd i* Exhibit 5, A1.
Y chostn a 0.35 from nngo of .18-
.42 npornd in Exhibit S, A1. Ap-
proximtttry iquol to tstimni for
Chicago thit 36% of wnploytts ire
of mployon of 200 or mon
(PMM&Co.. Carpoolmg Impict
Study).
VilM of 25 milos sdtettd to bo nwr
middlo of raportid nngo. Economic
fusibility raouinmmts of nnpooli
in mon rtltviat thtn ngion's ovorall
mngo trip lingtbs.
Modiin of rangi cbosn.
Vilui of 13 choson wn slightly ibon
middli of rengi, nflicting fmnblo
impact] assumption ind comparison
with valuo for "madium."
Economic fauibility nouinmonts of
nnpooh an man rthmat than any
ragionil variation in avanga nhido
occapancy.
Chosin valua is slightly balow reporttd
avaraga and at lowar and of raportod
ranga to reflect favonbla impact
assumption of baso analysis,
Choson valua is slightly bolow reportod
avanga and middlo of reporttd ranga
to reflect favonbla impact assumption
of base analysis.
Ran calculated as product of:
• ratio of new permanent carpools
formed to exposed employees (X);
• fraction of tot*) regional employees
exposed (Y);and
• avenge assumed carpool occupancy
(CPOCC).
Values of individual factors chosen to
reflect reasonably favonble impacts in
light of:
• competition from vanpooling com-
ponent of prognm (not usually
present for documented experiences
on en anowido scale); and
• fact that documented experiences
tend to bo repiesenietive of high
motivation and favonble condition.
(Continued)
A. 13
-------
TABLE A.5
(CONTINUATION 2)
ANALYTICAL ASSUMPTIONS
ANO PROCEDURES
BASIS OR SOURCE
COMMENTS
QUANTITY
VALUE ASSUMED FOR ANALYSIS
MEDIUM SIZED REGION LARGE REGION
Vinpool partici-
pation ran; esti-
mated iramtnr of
am vinpool
members per
regional employee
a i result of
program
0.008
0.005
C. ALLOCATION OF VMT REDUCTION
Th» regional reduction in non-circulatory wwkdiy VMT is
allocind to level of service (average speed), raid typo, ind
vehicle typt categories as follow:
• Tht reduction is assunwd to bt taken entirely from th«
"automobile" vehicle type category.
• AH non-circulatory VMT reductions are assumed to bt on
freeway and arterial roadvnys (local and collector roads
excluded).
• The VMT reduction is distributtd btnmn frmway and
arterial road types and among level of service (avenge
speed) catigorHn in proportion to (hi bas* VMT distri-
bution for the prototype region.
0. CIRCULATORY VMT INCREASE
The regional weekday change in circulatory (access and
passenger pick-up and drop-off) VMT associated with carpool/
vinpool programs is estimated ai:
c • 2 NEMP [CFACcp *CPPR + CFACvp 'VPPRl
when:
AVMT. » change in circulatory regional weekday VMT
associated with program
NEMP ' regional employment |
CPPR * carpool participation rate [ See section 1.8,
VPPR * vanpool participation rate I above
(Continued)
(Sea notation to right). For X:
"Marketing Plan to Accelerate the
Use of Vanpools" (FEA, July 1976)
states that most vanpool participa-
tion rates tend to cluster in aree of
3-6X of exposed employees. Low
end value of 0.03 chosen.
For Y: Survey tabulation results
from Carpoollng Impact Study
(PMM&Co.) on percent of employees
working for employers of 1,000 or
more at a site were used.
Medium: 20% value for Sacra-
Large: 17X value for Chicago
Assumption
Assumption
Assumption
Formula developed for report
analysis.
Rate calculated as product of:
• fraction of exposed employees who
form new permanent vanpools (X);
and
• fraction of total regional employ-
ment estimated to be exposed —
working for employers of 1,000 or
more at a site (Y).
Value of vanpool participation rate (X)
chosen at low end because:
• documented experiences rarely in-
cluded strong competition from a
carpool program; and
• documented experiences tend to be
for single large employers with high
motivation under favorable conditions.
Bus VMT (service) is not likely to change
significantly in response to program. A
successful program will minimize shifts
to pools from transit.
Little of line haul portion of work trip is
likely to take place on local roads.
The VMT changes likely to result would
not significantly change average speeds
on specific facilities.
(Continued)
A. 14
-------
TABLE A.S
(CONTINUATIONS)
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OR SOURCE
COMMENTS
(Continued)
CFACg. - is a drcttMtory factor representing tho
additional octets, pick-up, and/or drop-off
VMT per ocoipont associated with the
formation of • new carpoel
CFACyp - analogous to CFACgp. for n«w venpoals
Tho vthio of CFACCP wes miniated on tht bail of survey
dan on the number of addition* blocks drivm by cirpools
to pick up ifld drop off members, average carpool occupancy,
ind tfio following assumptions:
• 1 block-1/10 mite
• survey responses citing I pick-up distance of 0 blocks
should bo ignored a pertaining to "housohold" arpools,
inlikolY to bo afftctod by pool motchini programs.
In tht ibsonco of bettstr miloblo don. the vilui of CFACyp
i» assumed to bo equal to ttiit of CFACcp:
CFAC
CP
• CFAC
VP-
Modhim Sat Region
0.38 mile
Large Region
0.22 mito
Tho ovofill VMT incntn wot dinributtd, by *• ipproprioto
vohido typo (corpool or vonpool). to dio following thrto
circulatory rood typo/mnoo spood caagorioi us*d to ttti-
mm tminioin and hid conwmption impacts:
Ptrcont of Total VMT
•* Road Typo A»oraoa Spood Modiunt Raojon Lirgo Raojon
1 Local
2 Artorial
3 Artarial
ISrnpb
2Smph
ISmph
42%
2BS
32%
64%
18%
18%
Surrey data from PMM&Co. Cafpool-
in; Inipact Study on Itnfth in blocks
of additional carpool pickup »d
drop-off tranl.
Basad on ibova ainay dan and
following namptions:
• All rwdamal and mm of 5
block or las on local roods, IS
mph aswnnd avaraoa spood.
• Rasidairtial and travol in MCSSS
of 5 blocks ii /i on local roads
and K on irtarial roads of 25
mpn ivaiago spaod.
• All arnploymtm «nd traval on
mora congostad 15 rnph
Sacramanto sunoy rasurts vwra usod for
tha rnadiom sizod prototypo rtoioo.
Chicago survey results were used for the
largo prototype region.
II. GENERAL FOR SCENARIOS INVOLVING MULTIPLE
'APPLICATION Of FREEWAY CORRIDOR STRATEGIES
A. OVERALL APPROACH
As with the VMT changes associated with carpool/vanpool
programs, the VMT changes resulting from freeway corridor
stntagMS have both non-circulatory and circulatory
components.
B. NON-CIRCULATORY VMT CHANGES
The reduction in regional weekday non-circulatory VMT is cal-
culated by applying the percentage shifts used for vehicle
volume in the corresponding localized scenario instead to the
appropriate "affected" VMT categories. VMT reductions occur
because of the higher average occupancies of the vthrde types
txperioncing VMT inciaeses (at tho expense of greater VMT
decreeses for the low occupency modes).
Circulatory VMT increases include addi-
tional travel essociated with access to
ixpnss bus collection points for those
strategies resulting in express bus rider
ship incn
Travel Impact Assumption.
(Continued)
A. 15
-------
TABLE A.5
(CONTINUATION^
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
"Affected VMT" for thi freeway comdor regional scenarios ii
i subset of total regional VMT. It represents that regional
frarnny VMT estimated to bo directly affected by thi nltvint
strategies plui til* VMT wtimeod to b* on irterials serving the
sum radial corridors.
For till large prototype region, ttii "iffictid" weekday freeway
VMT was estimated it 1,073,100.
Till associated artiriil VMT was estimated at 735,900.
Thin VMT touts vmn distributed across vehicle types and
Iml of strvict desses exactly as was dam for tool regional
bra VMT, txcipt that VMT in tht A and F Iml of service
dissas was precluded as being inconsistent with conditions
approprine for implementing reserved lent strategies.
Following the calculation of non-circulatory VMT reduc-
tions and allocation to vehicle Type and initial level of ser-
vice classes.
ihita among level of service dasses were made
to simulate congestion effects.
C. CIRCULATORY VMT INCREASES
Associated with each shift to high occupancy vehicles induced
by a freeway strategy is assumed to be an increase in circulatory
VMT - travel associated with
model access or passenger pick-
ups and drop ofts. The following table presents the assumed
rates used to calculate circulatory VMT increases associated
with the strategy-induced modal shifts:
CORRIOOR MODAL SHIFT
FROM
(SOURCE)
AUTO
AUTO
LOCAL BUS
"NEW TRIP"
TO
CARPOOL
EXPRESS BUS
EXPRESS BUS
EXPRESS BUS
INCREASE IN
CIRCULATORY VMT
ON
15M.P.H.
LOCAL
1.0% of
Source
VMT Shift]
2.5% of
Source
VMT Shift
1.25% of
Source
VMT Shift
.25 md.
Per
Person
ON
25 M.P.H.
ARTERIAL
0.3% of
Source
VMT Shift
7.5% of
Source
VMT Shift
3.75% of
Source
VMT Shift
.75 mile
Per
Person
ON I
15 M.P.H.
ARTERIAL
0.3% of
Source
VMT Shift
_
-
-
BASIS OR SOURCE
(Continued)
Analytical assumptions.
Analytical assumption.
Analytical assumption.
Analytical assumptions
COMMENTS
The total regional weekday freeway VMT
of 12,304,600 was reduced as follows:
• Only 30% is peek period.
• Only 60% of this in peak direction.
• Only about 'A of this VMT is assumed
to be associated with radial freeways
whose geometries and base congestions
are appropriate for reserved lane
strategies.
This beers the same relation to the above
affected freeway VMT as the ratio of corri-
dor arterial to corridor freeway vehide
volume assumed in the 8 lane freeway
localized prototypes.
After the VMT shifts associated the sce-
nario strategy were made, the new V/C
ratio for each tentative LOS dess is calcu-
lated. If the new value it no longer in
the range for the class, all of the VMT in
that tentative LOS class is shifted to the
LOS dess appropriate for that V/C ratio.
For shift] to carpools: Based on: (a)
assumed additional per person travel for
pool access and passenger pick-up and
drop-off (.25 mile per person); (b) as-
sumed average carpool trip length (18
miles - assumed carpool trip length for
large region); and (c) assumed distribu-
tion of increase among road types -
64% on local roads at 1 5 mph ; 1 8%
on 25 mph arterials: and 18% on 15
mph arterials (same assumption as that
used for carpool/venpool programs).
A. 16
-------
TABLE A.S
(CONTINUATION 5)
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OR SOURCE
COMMENTS
(Contmutd)
Far Jiifa to txprin but: Band on:
(»l invmtd additional pir ptrso* travtl
for bin ican of 1 milo from into ind
0.5 milo from local but; (b) 10 mrio
auvmad mragt trip longth; and (e)
owmtd distribution of inenoio of 25H
01 local roads it IS mph »d 75X on 25
mph irtiriili (M chango it work «id of
trip).
For niw tript by express but: Band on:
(a) usumad 1 milo utn traval ptr pinon
ind (b) umi 25K/75X distribution M
local roads wd 25 mph irtiriali as
ibova.
III. GENERAL, f OR SCENARIOS INVOLVING MULTIPLE
APPLICATION Of AP
LAKE STRATEGIES
A. OVERALL APPROACH
Tho mtthodologv md assumad «alua> in tht saint tt for frit-
way strataom outiimd in action II of thit tabla. with tho
iKcaptions qiran htlow.
B. NON-CIRCULATORY VMT CHANGES
"Afftctad VMT" for tht imriol corridor nojonol scanarios it
that ragiand artarial VMT utimittd to bo directly ifftctad by
tht rtftnnt morvtd rntdian but lint stnttgin.
For tht laroi protctypt rtqion, tht "afftcttd" wtthdiy frttway
VMT wit Mtimtttd it 720.000.
Tho ptrctnt distribution of this VMT by vthidt typts was
assamtd to bt tht samt ustd in tht localiztd mtdiin but lant
scanario |saa tahla AJ, saction II.I
Analytical assumptions.
C. CIRCULATORY VMT CHANGES
In iddition to tho changas outiintd far tht ngjond frttway
corridor scanarim, ineraasas in VMT associatad with congos-
tion-inducod routt dhrarsions wtrt also tstimatad whan tht
V/C ratio for iny group of VMT wa tstimattd to ixntd 1.1.
Analytical assumption.
Tht 1,073,000 "afftctid" fmway VMT
for tht rttjonal frttwty strattgits corn-
sponds to trwtl on roughly four, 10
mill radial frttways.
In tht sunt typt of laroa prototypt rtgion,
it is issunwd that roughly 8 major radial
imrnli with in mngt Itngth of 9 milts
would bt ippropriao for ipplication of
tht irttrial Itntigy.
Tht "ifftctid" VMT istimtta is basad on
this 72 milts of roadway; an assumtd
ivtngt piik hour volumt of 2,000 vph
(down from 2^50 vph issumad for stg-
mtnt 1 milt from CBO in localiztd
prototypt scanarin); ind • fictor of S
to eonvtrt paik hour to i.m./p.m. ptak
panods traval.
(Connnutdl
A. 17
-------
TABLE A.5
(CONTINUATION 6)
ANALYTICAL ASSUMPTIONS
AND PROCEDURES
BASIS OR SOURCE
COMMENTS
(Continued)
That portion of any affected VMT eitimatad to txcnd thi
1.1 value for V/C wu assumed diverted to alternate artarial
routes operating it E Intl of service. In iddition, another 28%
(of ttiiJ divartad VMT) wu also added to thi 15 mph arterial
total as in approximation of thi additional tnvii associated
with thi routa diversions.
Thi 28% routa dhnnion circuitry factor
wai basad on (a) an assumed additional
travel of 14 mila aach way because of
thi dhranion; (b) a 9 mHi arterial length;
and (c) an assumad 20% of thi arterial
langth operating at E lava) of sarvka
(thoia portion! from which thi divanioni
an raott likely).
II. TRAVEL SHIFTS FOR INOIVIOUAL SCENARIOS
A. CARPOOL/VANFOOL PROGRAM SHIFTS
Thi traval shirts resulting from tmployar carpool/vanpool pro-
grams wara calculatid using the mithodology and assumptions
of saction I, 3 of this tabla in all regional scanarios containing
a carpool/vanpool program.
8. FREEWAY AND ARTERIAL CORRIDOR SHIFTS
Each multipla application fraaway or artarial corridor ttratagy
in thi regional scanarios corresponds to ona or more of tha
nratagiai or combination programs in tha tan localized sca-
narios.
Whm an «act matrh (in tarms of strategy ajid assumed impact
lava* - modast or favorable) ixistad batwaan tha corridor com-
ponaot of a regional scanario and ona of tha localizad scanarios,
then tha regional corridor VMT impact! ware istimatad as
follows:
• for each specific moda-to-moda vihida volumi shift esti-
matid in tha localized scenario, an analogous moda-to-
moda VMT shift is istimatad for tha regional scenario;
• tha percent of base "affected" source mode VMT shifting
in each case is assumad to ba tha sama as tha corresponding
percent vehicle volume shift in tha localized scanario; and
• VMT reductions mult because tha average vehicle occu-
pancy of tha "receiving" mode is higher thin that of the
source moda.
For some regional scanarios, an exact match with one of tha
localizad scanarios did not exist. In thasa cases, adjustments
in the most closely matching localizad scanario shifts wen
made, as follows:
• Scenario 15: To simulate the modest impact] assump-
tion for this strategy, for which only a favorable impact
localizad scenario counterpart exists, travel shifts resulting
from a 30% (instead of 40%) final corridor bus modal
split ware usad.
• Scenario 17: To simulate tha modest impacts assumption
for this strategy, for which only a favorable impact localized
scenario counterpart exists (Scenario 2), tnvel shifts resulting
from a 55% increase in affected express bus VMT and a 65%
increase in affected carpool VMT were used in place of thi
100%/100% assumed shifts in Scanerio 2.
For thosa scanarios with "modast" in-
stead of "favonbla" impact assumptions,
tha basa ("favorable") traval impacts are
scaled down by a factor of !4 (correspond-
ing to an assumed halting in tha program
participation rates).
Analytical assumptions.
Traval impact assumptions.
The 55%/65% values reflect tha assumption
that carpooling will tend to ba more attrac-
tive than express bus undir modast impact
conditions. These values also yield approxi-
mately the same modest/favoreble impact
ratio for scanario pair 17 and 18 as achieved
for scenario parr 13 and 14.
A. 18
-------
TABLE A.6:
ESTIMATING HIGHWAY EMISSIONS
I. GENERAL APfROACH
Estimates of regional highway emissions nd lint source tmiaim
intensity won mede by applying Jimmy, 1971 vehicle uh«uit
emission ficton published by the UA Emnranmontil Pronctioa
Agency, Office of Transportation and Ltod Uu Policy. Individual
emission ficton wore computed by mHm of in EPA computer
program, bind oo methodology and (vpditod) parameters eppeoring
in MOHJJO Source Emlnioii Ficton. Interim Oocumtnt. jgm, 1977
(EPA, OTLUP).
Except as specified bolow. avenge default viluts were uud in calcu-
lating the emission ficton.
II. VEHICLE TYPE CONVENTIONS
Emnsjon fman were stpiratfly calculmd and ipplitd to tht
followiftf standard EPA vehicle types:
LOV - light duty vehicle
LOT! - light dirty track (unto 6.500 las.)
LOTj - lifht duty tnck (8.500-8,500 Ibs.)
HOG - bony duty gasoline vehicle
HOD - heavy duty dies* vehicle
Tbt foor besic vehicle types ustd for travel impict estimation pur-
poses in this rtport vnon tquivalonced to thf above nudird EPA
categories u follows:
Auto "LOV
Carpool * LOV, assumed to any 500 Ibs. addrtioml vMioht
BM • HOD
Truck totata in illocaud unonq four EPA standard daises according
to the following assumed urban truck distribution:
* LOTt
* LOTj
* HOG
•* HOD
* Trucks xS/H
a Trucks x 8/14
* Trucks/14
* Trucks/14
* Tracks
III. HOT AHO COLO START ASSUMPTIONS
For ijn. peek hour regional (missions calculations, the following distri-
bution of vehicle operating conditions are assumed for ill vehicle and
facility types:
20% cold start
10% hot start
70%
For i.m. peek hour line source emission intensity calculations, the fol-
lowing distributions of vehicle operating conditions were assumed for
the CO imped aree (approximately 1 mile out from the CBO):
Type of Traffic Cold Hot Stable
Buses, inbound freeway - - 100%
Buses, outbound freeway 5% 5% 90%
Other inbound freeway vehicles 15% 5% 90%
Other outbound freeway vehicles 20% 15% 85%
All inbound arterial vehicles 10% 5% 85%
All outbound arterial vehicles 20% 15% 65%
IV. ARTERIAL FLOW ADJUSTMENT FACTOR
Given the illustrative, prototype nature of the analysis, it was inappro-
priate to attempt detailed queue formation and intersection analyses
to account for the impact of traffic controls and intersection conflicts
on arterial emission rates (over and above the impacts reflected in
average speed). However, it was nevertheless important in calculating
arterial emissions to at least generally take into account these stop-
end-go conditions which differentiate arteriols from "slow freeways."
A microscalo analysis of a typical arterial intersection was conducted
to estimate the additional emissions associated with intersection delay.
The results of this analysis indicated diet four-way queuing at arterial
intersections increased arterial emissions by an average of 43% over
whet they would hem been at the same average speeds without the
intersection delays. This emission increment factor was applied to all
calculations for artarials and local streets to account for these inter-
section effects.
V. REGIONAL EMISSION ESTIMATES
Estimates of regional HC, NO, and CO emissions were made by multi-
plying the projected signed changes in weekday regional VMT (disaggre-
gated by average speed, facility type, and vehicle type) by the corre-
sponding emissions rates and summing over ell disaggregation types.
VI. LINE SOURCE EMISSION INTENSITY ESTIMATES
In order to meke estimates of the localized CO concentration impacts
of corridor-oriented strategies, it is first necessary to estimate the line
source intensity of CO emissions for the affected freeway and/or
irteriel facilities. After total projected vehicle volume on a facility is
allocated to the seperate lanes on the basis of the scenario specifica-
tions ind typical lane distributions, the line source emission intensity
(e.g., /jgrnVrmter-wc.) is calculated for aach lane by multiplying lane
volume by the appropriate composite CO emission factor. This com-
posite factor corresponds to the vehicle type, mode of operation,
average speed, and temperature assumed.
(Continued)
A. 19
-------
TABLE A.7:
ESTIMATING LOCALIZED CO CONCENTRATION IMPACTS
I. EPA HIWAY MODEL ESTIMATES
The CO line source emission intensities discussed in Table A.6 are
input to a modified version of the EPA HIWAY model to provide
estimates of a.m. peak hour CO concentrations associated with the
emissions from the affected highway facilities. Unlike the standard
version of HIWAY, which calculates CO concentrations at 5 specified
receptors, the modified version calculates concentrations for an
11 x 11,121 receptor grid, set to cover a mile square area.
The prototype corridor facilities were oriented within the grid so that
the primary corridor facility runs parallel to the grid point rows and
so that the maximum concentration receptor is located 50 feet (along
the perpendicular) downwind from the edge of the primary facility.
Level topography is assumed in the model.
For each localized scenario, HIWAY model estimates of grid point
CO concentrations were made for each of the three meteorological
conditions defined in Exhibit 11.
II. AVERAGE EIGHT HOUR CO CONCENTRATIONS
Although CO concentration impact estimates were made only for the
a.m. peak hour, attainment of the national standard for maximum
average eight hour CO concentrations is an important consideration
in some areas.
Exhibit 14 can be used to estimate the maximum 8-hour CO
concentration (including background CO) using the estimated
peak 1-hour CO concentrations (from vehicular traffic only)
in Exhibits 13 through 15. A background CO concentration
of 5,714 ug/m (5 ppm) and a 0.7 ratio of peak 8-hour to peak
1-hour CO concentrations were used to develop Exhibit 14.
The source of these factors is:
GCA Corporation. Identification and Evaluation
of Localized Violations of Carbon Monoxide
Standards • Volume I: Guidelines (Draft Final
Report). Prepared for EPA - Region I Office.
November 1975, pgs. 11-12 and 11-13.
A.20
-------
TABLE A.8:
ESTIMATING REGIONAL FUEL CONSUMPTION IMPACTS
I. CALCULATION PROCEDURE
The change in weekday regional fuel consumption in gallons is esti-
mated by multiplying the signed projected weekday VMT changes
for a scenario (disaggregated by facility type, vehicle type, and level
of service/average speed class) by the corresponding disaggregate fuel
consumption rate and summing these products over all of the dis-
aggregation classes.
The change in annual regional fuel consumption is estimated as 250
(number of work days per year) times the weekday value, since all
of the scenario strategies are essentially work day strategies.
II. DISAGGREGATE FUEL CONSUMPTION RATES
The fuel consumption rates used in the analysis were estimated from
fuel consumption and vehicle type distribution data appearing in
Cheracteristics of Urban Transportation Systems (July. 1977 version)
as follows:
Table 3-6: bus fuel consumption rates
Table 4-5: auto and track fuel consumption rates and vehicle
type distribution on freeways
Table 4-6: auto and truck fuel consumption rates and vehicle
type distribution on arterial streets
The average speeds by level of service class appearing in Table A.3, IA
were used so that the fuel consumption rates could be expressed and
applied directly in terms of level of service class.
Local streets were assumed to be arterial streets for fuel consumption
calculation purposes.
Fuel consumption rates for speeds beyond the range of speeds for
which rates were available were assumed to be the rates for the closest
reported speed. Rates for speeds between reported speeds were esti-
mated through linear interpolation.
A 2% roadway grade was assumed for buses in estimating fuel con-
sumption rates.
Vanpools were assumed to be 2-ton light duty trucks for the purpose
of fuel consumption estimation.
A. 21
-------
TABLE A.9
ILLUSTRATIVE CALCULATION OF TRAVEL SHIFTS
This section illustrates how the procedures and assumptions cited in Table A.1 - A.5 were used to estimate travel impacts for
the localized and regional scenarios. Scenarios 5 and 12 are cited as representative localized and regional scenarios, respectively.
I. Localized Scenario Travel Shifts (Scenario 5)
A. "Before" Peak Hour Travel Conditions
Exhibit 10 presents the distribution of "before" condition vehicles by type. This distribution was further stratified as
shown below, using assumptions shown in item 0 of Table A.2.
Freeway: Vehicle Type Vehicles per Hour* Persons per Hour**
Single Occupant Auto 4,967 "\ 4,967
Two Occupant Auto 1,323 J '2 2,648
Three(+) Occupant Auto (Carpools) 330 1,192
Express Bus 26 1,170
Local Bus - -
Trucks 350
Corridor Arterials:**
Single Occupant Auto 3,363 3,363
Two Occupant Auto 897 1,794
Three(+) Occupant Auto (Carpools) 224 806
Express Bus - -
Local Bus 78 4,290
Trucks 238
* From Exhibit 10.
** From project working papers.
B. Travel Impact Assumptions
Assumed percentage increases in freeway bus ridership and carpools of 125 percent, and 95 percent, respectively, for
scenario 5 are taken from Table A.4.
C. Peak-Hour Carpool Shifts
"New" Carpools on Freeway = (.95X330) = 314 carpools in peak hour. This represents 1,130 persons in carpools using
an average carpool occupancy of 3.6.
A. 22
-------
TABLE A.9 (Continued)
Based on Item C of Table A.4, the increase in carpools and the corresponding reduction in vehicular volumes on arterial:
and freeways were achieved from the following sources:
Percent of* Vehicle Reductions by Occupancy Class
Source of Carpools New Carpoolers New Carpools 1 2_ 3(+)Total
Arterial Carpools 10 31 - - 31 31
Arterial Auto
(1,2 occupant) 18 57 133** 36** - 169**
Freeway Auto
(1.2 occupant) 72 226 530** 142** - 672**
100 314 872
* From Item C of Table A.4.
** As noted in Item C of Table A.4, shifts from 1 and 2 occupant autos to carpools were allocated in proportion
to the base number of persons in each occupancy class shown in A. above.
0. Peak Hour Transit Ridership Shifts
Increase in peak hour transit ridership on freeways = (1.25)(1,170) = 1,463 riders. Total peak hour transit ridenhip
on the freeway = 2,633 riders (1,170 (i.e., base) + 1,463 (\jt., increase)).
Using an average load factor of 40 riders per bus, an estimated 66 express buses are assumed to operate on the re-
served freeway lane during the peek hour under the "after" conditions. This is 40 more buses then in the "before"
condition.
Based on Item B of Table A.4, the increase in transit ridenhip and the corresponding reduction in vehiculer vol-
umes on arterials and freeway were achieved from the following sources:
Source of Transit
Ridership
Induced
Local (Arterial) Bus
Arterial Auto
(1,2 occupant)
Freeway Auto
(1,2 occupant)
Percent of
New Transit Riders
*
20 #
16^
647?
New Riders
146
263
211
843
1,463
Vehicle Reductions by
1 2 3(+)
_
_
118® 32® 8®
549® 147® -
Occupancy
Total
-
-
158®
696®
854
A. 23
-------
TABLE A.9 (Continued)
1 From Item B of Table A.4.
* Assumed as 10% of 1,463 new transit riders.
^•Percentages apply to non-induced (1,463 - 146 = 1,317) increase in transit ridership.
®
As noted in Item B of Table A.4, shifts from 1,2 and 3+ occupant autos to transit were allocated
in proportion to the base number of persons in each occupancy class shown in A. above.
E. Peak Hour Freeway Traffic Volume Shifts
The impact of the above carpool and transit shifts on peak hour, peak direction freeway traffic volumes is
presented below.
"Before" Vehicles* Vehicle Changes on Freeway from "After" Vehicles*
Vehicle Type per Hour Carpool Shifts Transit Shifts per Hour (unrounded)
Auto 6,290 -672 -696 4,922
Carpool 330 +314 - 644
Bus 26 - +40 66
Trucks 350 - - 350
* See Exhibit 10 for these estimates.
F. Peak Hour Corridor Arterial Traffic Volume Shifts
Peak hour traffic volume shifts on corridor arterials which are reported in Exhibit 10 were estimated using
the same process presented above for freeways.
G. Operating Speed Estimates for Freeway
As noted in Item B of Table A.2, average vehicle operating speeds for the reserved and non-reserved freeway lanes
were estimated based on computed volume to capacity (v/c) ratios for each scenario.
For scenario 5, the "before" and "after" peak hour vehicle volumes (from point E above), hourly capacities, V/C
ratios, and corresponding average peak hour operating speeds for the reserved and non-reserved lanes in the peak-
direction of travel are presented below:
Peak Hour, Peak Direction, Hourly Average*
Freeway Volume (Unrounded) Capacity (VPH) V/C Ratio Operating Speed (MPH)
"Before" Condition
. Non-Reserved Lanes 6,996 7,000 1.00 28
"After" Condition
. Non-Reserved Lanes 5,272 5,250 1.00 30**
. Reserved Lanes 710 1,750 0.41 43
* Tables 33 and 34 of the report Characteristics of Urban Transportation Systems (1974 edition) and the Highway
Capacity Manual were used to estimate operating speeds.
** Assumes that ramp metering will result in a small improvement in average peak hour vehicle operating speed
(i.e., from 28 to 30 mph) even though the V/C ratio in non-reserved lanes equals 1.0 in both the "before"
and "after" conditions.
A. 24
-------
TABLE A.9 (Continued)
II. Regional Scenario Travel Shifts (Scenario 12)
A. Travel Assumptions
The assumed travel, trip length and employment characteristics used to estimate travel shifts in this scenario
are presented in item B of Table A.5. These assumptions are summarized for convenience below:
VALUE ASSUMED FOR ANALYSIS
QUANTITY LARGE REGION
Regional employment 1,152,766
Average work trip length among
those forming carpools 16 miles
Average work trip length among
those forming vanpools 25 miles
Average carpool vehicle occupancy 2.9
Average vanpool vehicle occupancy 11
Average overall commuter vehicle
occupancy 1.20
Carpool participation rate; estimated
number of new carpool members per
regional employee as a result of pro-
gram 0.0255
Vanpool participation rate; estimated
number of new vanpool members per
regional employee as a result of pro-
gram 0.005
B. Non-Circulatory VMT Change
The above estimates were used in conjunction with the following formula to estimate the change in regional
weekday non-circulatory VMT associated with the carpool/vanpool program:
AVMTNC - 2 NEMP
CPTL CPTL\ / VPTL _ VPTL\
PPOCC" BOCCJ CPPR \VPOCC BOCC
A. 25
-------
TABLE A.9 (Continued)
where:
AVMT,
NEMP
CPTL
VPTL
CPOCC
VPOCC
BOCC
CPPR
VPPR
NC
change in non-circulatory regional weekday VMT associated with program
regional employment
average work trip length among those forming carpools
average work trip length among those forming vanpools
average carpool vehicle occupancy
average vanpool vehicle occupancy
average overall commuter vehicle occupancy
carpool participation rate; estimated number of new carpool members per
regional employee as a result of program
analogous to CPPR, for vanpools
The calculation of this change is shown below:
AVMT
NC
K16 16\ /25 25\ / v]
£9 ~lTJ ('0255) + V~TF " W (•005)J " -673,446
C. Circulatory VMT Change
The regional weekday change in circulatory (access, passenger pick-up and drop-off) VMT associated with
carpool/vanpool programs was estimated using the following formula (see item D of Table A.S):
A VMTC = 2 NEMP [CFACcp * CPPR + CFACvp » VPPR]
where:
NEMP, CPPR, AND VPPR are as in section A above.
AVMTp = change in circulatory regional weekday VMT associated with program
= is a circulatory factor representing the additional access, pick-up, and/or drop-off
VMT per occupant associated with the formation of a new carpool
yp - analogous to CFACpp, for new vanpools
CFAC
The value of CFACQp was estimated on the basis of survey data on the number of additional blocks driven
by carpools to pick-up and drop-off members, average carpool occupancy, and the following assumptions:
. 1 block = 1/10 mile; and
. survey responses citing a pick-up distance of 0 blocks should be ignored as pertaining to
"household" carpools, unlikely to be affected by pool matching programs.
A. 26
-------
TABLE A.9 (Continued)
In the absence of better available data, the value of CFACyp is assumed to be equal to that of CFAC»p:
Large Region
CFACcp-CFACvp: 022mj|i
The calculation of this change is shown below:
A VMTC = 2(1,152,766) [(.22K.0255) + (.22X.005)]
A VMTC»+15,447
D. Total Weekday Regional VMT Change
Total Change in VMT - A VMTNC +AVMTC
= -673,446 + 15,447
= -657,999
/ 657.999 \
The percent reduction in VMT =° I43 944 599 I 100 = 1.5%
E. VMT Distribution by Facility Type
Tables A.3 and A.5 (items C and D) describe how the change in weekday regional VMT was allocated by level of
of service (i.e., speed), road type, and vehicle type.
A. 27
-------
APPENDIX B
UNIT COST ASSUMPTIONS
ITEM
COST (in 1076 Dollars)
SOURCE
1. Bus Capital Cost
(47-51 Passengers)
2. Bus Operating and Maintenance
Cost
3. Park and Ride Lot
A. Capital
B. Operating and Maintenance
Cost
4. Bus Ramps
5. Contra-Flow Arterial Lane
6. Reserved Freeway
Bus/Carpool Lane
A. With-Flow
B. Contra-Flow
$66.000
$1.49 per bus mile for population service areas of
750,000-2,500,000
$1,000 land and construction cost/stall (in 1976 dollars);
this is based on a land cost of $2 per square foot
$165 annual operating cost/stall (in 1976 dollars);
includes property tax allowance.
$759,244 (in 1972 dollars) for 9 bus ramps; 114,815
per ramp (in 1976 dollars)
$9,200/1.5 miles for sizing, striping, etc.
$100,000 capital cost for Santa Monica Freeway
$22,000 per mile annual operating cost (Assumption)
$50,000 per mile used based on several projects
$22,000 per mile used based on several projects
DeLeuw. Gather & Co. and Rock Creek Associates.
Characteristics of Urban Transportation Systems: A
Handbook for Transportation Planners. Prepared for
UMTA. July 1977. Page 111-18, Table 3-14.
DeLeuw. Gather & Co. and Rock Creek Associates.
Characteristics of Urban Transportation Systems: A
Handbook for Transportation Planners. Prepared for
UMTA. July 1977. Page III 7, Table 3-5.
DeLeuw, Gather & Co. and Rock Creek Associates.
Characteristics of Urban Transportation Systems: A
Handbook for Transportation Planners. Prepared for
UMTA. July 1977. Page IV-22, Table 4-15.
Butier-Rhrgrose-Wolsfield. Inc. Final Report for the I-3SW
Urban Corridor Demonstration Project. Prepared for UMTA
August 1975.
NCHRP Report 143. Bus Use of Highly
State of Art 1973. Page 251. Table C-8.
Urban Mass Transportation Administration. Service and
Methods Demonstration Program Annual Report. April
1977. Page 237.
DeLeuw. Gather & Co. end Rock Creek Associates.
Characteristics of Urban Transportation Systems: A
Handbook for Transportation Planners. July 1977.
Page 111-17, Table 3-13.
-------
APPENDIX B (Continued)
ITEM
COST (in 1976 Dollars)
SOURCE
Ramp Metering
$27,200 per ramp for capital and installation
(based on traffic-response system cost range of
$15,000-30,000 in 1972 dollars)
Annual operating and maintenance cost = $2,042 per
ramp (based on $1,500 per ramp in 1972 dollars)
P. Everall. Urban Freeway Surveillance and Control:
The State of the Art. Prepared for FHWA. November
1972. Page 143.
W
•
to
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing]
1. REPORT NO.
EPA-400/2-78-002 a
3. RECIPIENT'S ACCESSIOWNO.
4. TITLE AND SUBTITLE
Air Quality Impacts of Transit Improvements, Preferential Lane and Carpool/Vanpool
Programs
5. REPORT DATE
March 1978
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
John F. DiRenzo and Richard B. Rubin
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Peat, Warwick, Mitchell & Co.*
1025 Connecticut Avenue, N.W.
Washington, D.C. 20036
10. PROGRAM ELEMENT NO.
2AA63S
11. CONTRACT/GRANT NO.
68-01-3912
12. SPONSORING AGENCY NAME AND ADDRESS
Office of Transportation and Land Use Policy**
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final Report
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
* In Association
with:
Engineering-Science
7903 Westpark Drive
McLean, Virginia 22101
** In cooperation with:
U ^.Department of Transportation
Washington, D.C.
16. ABSTRACT
This report has been prepared in accordance with Section 108(f) of the Clean Air Act, as
amended, August 1977. It is intended to assist urban areas in developing State Implementation
Plans and integrating their transportation system management and air quality planning programs
as required by FHWA, UMTA, and EPA.
The report analyzes the air quality, travel, energy consumption, economic, and cost im-
pacts of three types of transportation programs: priority treatment for high occupancy vehicles
on freeways and arterials; areawide carpool and vanpool programs; and transit fare reductions
and service improvements.
Important factors (e.g., meteorological conditions, traffic volumes and speeds and changes
in modal choice) likely to influence air quality and emissions for the above programs are also
analyzed.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Air Pollution Abatement
Carpooling
Automobile Traffic Reduction
Transportation Planning
Air quality
Travel Impacts
Reserved Lane Strategies
Vanpooling/Carpooling
18. DISTRIBUTION STATEMEN1
Unlimited Distribution
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
------- |