EPA Releases MOVES2010 Mobile
Source Emissions Model:
Questions and Answers
Ql. WhatisMOVES2010?
Al. MOVES2010 is the state-of'the-art upgrade to EPA's modeling tools for
estimating emissions from highway vehicles, based on analysis of millions of
emission test results and considerable advances in the Agency's understanding
of vehicle emissions. MOVES2010 replaces the previous model for estimating
on-road mobile source emissions, MOBILE6.2,
Q2. Why is EPA replacing MOBILE6.2 with MOVES2010?
A2. The Clean Air Act (CAA) requires EPA to regularly update its mobile source
emission models. EPA continuously collects data and measures vehicle emis-
sions to make sure the Agency has the best possible understanding of mobile
source emissions. This assessment, in turn, informs the development of EPA's
mobile source emission models. MOVES2010 represents the Agency's most
up'to'date assessment of on-road mobile source emissions. MOVES2010 also
incorporates several changes to the EPA's approach to mobile source emission
modeling based upon recommendations made to the Agency by the National
Academy of Sciences,
Q3. Can MOVES2010 be used for state implementation plans and transportation
conformity?
A3. MOVES2010 can be used to estimate air pollution emissions from cars, trucks,
motorcycles, and buses. It will be approved for use in official state implementation
plan (SIP) submissions to EPA and for transportation conformity analyses
outside of California. It can also be used to estimate the benefits from a range
United States
Environmental Protection
Agency
Office of Transportation and Air Quality
EPA-420-F-09-073
December 2009
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of mobile source control strategies, for more general analyses of national or local emissions
trends, and for policy evaluation. MOVES2010 is EPA's best available tool for quantifying
criteria pollutant and precursor emissions, as well as for other emissions analyses of the
transportation sector.
Prior to this official release of MOVES2010, the MOBILE6.2 motor vehicle emission factor
model was the only model approved for performing SIP and transportation conformity
analyses outside of California (where the approved model for these analyses is currently
the EMFAC2007 model). EPA will be publishing a Federal Register notice of availability
in the near future to approve MOVES2010 for official purposes. Upon publication of the
Federal Register notice, MOVES2010 will become EPA's approved motor vehicle emission
factor model for estimating volatile organic compounds (VOCs), nitrogen oxides (NOx),
carbon monoxide (CO), direct particulate matter (PM10 and PM2.5) and other pollutants
and precursors from cars, trucks, motorcycles, and buses by state and local agencies outside
of California. EPA intends to include in the notice a two-year grace period for using
MOVES2010 for transportation conformity purposes.
Q4. When should MOVES2010 be used for SIP and transportation conformity analyses?
A4. In general, EPA believes that MOVES2010 should be used in ozone, CO, PM, and
nitrogen dioxide SIP development outside of California as expeditiously as possible. The
CAA requires that SIP inventories and control measures be based on the most current
information and applicable models that are available when a SIP is developed.
Regarding transportation conformity, EPA and DOT intend to establish a two-year grace
period before MOVES2010 is required for new transportation conformity analyses outside
of California. EPA will publish a Federal Register notice of availability in the near future
to approve MOVES2010 for official purposes.
For more information on the requirements regarding the use of MOVES2010 for SIP and
transportation conformity analyses, including implementation of the MOVES2010
conformity grace period, see EPA's "Policy Guidance on the Use of MOVES2010 for
State Implementation Plan Development, Transportation Conformity, and Other
Purposes," available at
www.epa.gov/otaq/stateresources/transconf/policy.htm#models.
Q5. Can MOVES2010 be used to estimate greenhouse gas emissions?
A5. MOVES2010 is currently the best tool EPA has for estimating greenhouse gas (GHG)
(1 ^ emissions from the transportation sector. It is a significant improvement over MOBILE6.2
and previous versions of MOVES for GHG estimation. State and local agencies esti-
mating GHG emissions in the transportation planning process should consider using
J MOVES2010 for GHG emissions analyses in the future.
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Q6. Can MOVES2010 be used to estimate mobile source air toxics?
A6. MOVES2010 estimates emissions for the following mobile source air toxics (MSATs):
benzene, 1,3-butadiene, formaldehyde, acetaldehyde, acrolein, naphthalene, ethanol,
and MTBE. MOVES2010 is EPA's best available tool for quantifying emissions of these
MSATs. State and local agencies, academic institutions, and other interested parties who
are interested in analyzing MSAT emissions from transportation projects are encouraged
to use MOVES2010. EPA is working to integrate additional MSATs into the MOVES
modeling framework in the near future,
EPA notes that there are no SIP and transportation conformity requirements for air toxics.
Regarding the analysis of MSAT emissions in the National Environmental Policy Act
(NEPA) process, DOT has responsibility for implementing NEPA for federally-funded or
approved transportation projects.
Q7. Why has EPA changed the name of its mobile source model from "MOBILE" to
"MOVES"?
A7. The name "MOVES" is an acronym for "Motor Vehicle Emission Simulator." The name
change signals the new approach to projecting mobile source emissions being taken in
the new model. The MOVES generation of models is not merely an upgrade of the previous
MOBILE model using more recent emissions data; it is brand-new software, designed
from the ground up to estimate emissions at a more detailed level.
The more detailed approach to modeling allows EPA to easily incorporate large amounts
of in-use data from a wide variety of sources, such as data from vehicle inspection and
maintenance (I/M) programs, remote sensing device (RSD) testing, certification testing,
portable emission measurement systems (PEMS), etc. This approach also allows users
to incorporate a variety of activity data to better estimate emission differences such as
those resulting from changes to vehicle speed and acceleration patterns. For example, the
improvements in MOVES2010 will allow project-level PM2.5 and PM10 emissions to be
estimated.
The current version of the model - MOVES2010 - is so named to indicate the first year
in which the model may be used in SIPs and conformity determinations, and to clearly
distinguish the model from its precursor, Draft MOVES2009,
Q8. What has EPA done to prepare users for the release of MOVES2010?
A8- In APril 20°9, EPA released "Draft MOVES2009" as a work-in-progress to solicit user
comments that were then used to improve the official final version: MOVES2010. In
addition to aiding EPA as it worked toward finalizing MOVES2010, the draft model
allowed potential users to gain valuable experience with the new input formats for the
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MOVES generation of models.
Between the release of Draft MOVES2009 and MOVES2010, EPA and the Federal High-
way Administration (FHWA) conducted a total of 20 training sessions across the country
for state and local users of the MOVES model. EPA also made training materials avail-
able on its website at http://www.epa.gov/otaq/models/moves/index.htm.
In addition to the above training, EPA has developed several documents to assist in
implementing MOVES2010, including the following:
"MOVES2010 User Guide": This guide provides detailed instructions for setting up
and running MOVES2010. Available at
www.epa.gov/otaq/models/moves/index.htm.
"Policy Guidance on the Use of MOVES2010 for State Implementation Plan
Development, Transportation Conformity, and Other Purposes": This document
describes how and when to use the MOVES2010 emissions model for SIP develop-
ment, transportation conformity determinations, and other purposes. Available at
www.epa.gov/otaq/stateresources/transconf/policy.htm#models.
"Technical Guidance on the Use of MOVES2010 for Emission Inventory Prepara-
tion in State Implementation Plans and Transportation Conformity": This document
provides guidance on appropriate input assumptions and sources of data for the use of
MOVES2010 in SIP submissions and regional emissions analyses for transportation
conformity purposes. Available at
www.epa.gov/otaq/models/moves/index.htm,
"Transportation Conformity Guidance for Quantitative Hot-spot Analyses in PM2.5
and PM10 Nonattainment and Maintenance Areas": This document explains how to
use MOVES2010 to complete hot-spot analyses required for projects of local air quality
concern in PM2.5 and PM10 nonattainment and maintenance areas. This guidance
is presently under development. When it is available, it will be posted on the EPA's
transportation conformity policy guidance website (www.epa.gov/otaq/stateresources/
transconf/policy.htm). EPA will be making a draft available for public comment prior
to finalizing this guidance.
Q9. How do MOVES2010's inputs and outputs compare to EPA's previous mobile source
emission models?
A9. Unlike EPA's previous mobile source emission models, MOVES2010 has a graphical user
interface (GUI) which allows users to more easily set up and run the model. More funda-
mentally, it has been designed to do calculations with information in databases, using the
J open source database management software known as MySQL,
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The database-centered design provides users much greater flexibility regarding output
choices. Unlike earlier models which provided emission factors in grams-per-mile in fixed
output formats, MOVES2010 output can be expressed as total mass (in tons, pounds,
kilograms, or grams) or as emission factors (grams-per-mile and in some cases grams-
per- vehicle). Output can be easily aggregated or disaggregated to examine emissions in a
range of scales, from national emissions impacts down to the emissions impacts of indi-
vidual transportation projects,
The database-centered design also allows EPA to update emissions data incorporated
in MOVES2010 more easily and will allow users to incorporate a much wider array of
activity data to improve estimation of local emissions. For example, the improvements in
MOVES2010 will allow project-level PM2.5 and PM10 emissions to be estimated,
Q10. How does MOVES2010 compare to previously released drafts of MOVES?
A10. The first draft release in the MOVES generation of mobile source emission models -
MOVES2004 - was a proof-of-concept model that only looked at two aspects of mobile
source activity: energy consumption and GHG impacts. MOVES2004 was followed by
the MOVES Demo model, which was released in May 2007. MOVES Demo allowed
potential users to gain familiarity with what would be the basic structure for subsequent
iterations of the model but included only placeholder values for emission rates. MOVES
Demo was released to get comments from likely users on the user interface and other
model functions. With the release of Draft MOVES2009 in April 2009, EPA provided a
more refined version of the model for likely users to test and comment upon,
In response to the comments received regarding Draft MOVES2009, EPA has made many
improvements to the model. For example, MOVES2010 runs faster. It includes an improved
emission rate calculator that provides "lookup table" results for starts and evaporative
emissions as well as exhaust emissions. It eases entry of local fuels, heavy-duty reflash
parameters, and other user inputs. MOVES2010 includes the ability to model new
pollutants and precursors (sulfur dioxide, ammonia, nitrogen dioxide, and nitric oxide)
and includes estimates of emissions from motorcycles. EPA has also expanded the capa-
bilities of MOVES2010 for project-level analyses by including a graphical user interface
for such analyses,
EPA also made emission rate improvements based upon newly available data and the
comparisons of Draft MOVES2009 results to real-world emission measurements. These
changes include improved estimates of emissions from heavy-duty trucks and older light -
duty vehicles, as well as improved estimates of emissions at high speeds and accelerations,
Because of these changes, inventories and emission rates generated by MOVES2010 will
differ from those generated using Draft MOVES2009,
Ql 1. How do MOVES2010 emission estimates compare to those of MOBILE6.2?
^ ^ Al 1. As part of its own internal testing, EPA performed a preliminary comparison of
MOVES2010 to MOBILE6.2 using approximate local data for several different urban
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and NOx emissions for light'duty cars and trucks. In reviewing these data, EPA found
little change in CO from our original MOBILE6.2 projections, lower VOC emissions,
and a noticeable increase in NOx emissions.
Also in support of MOVES2010 development, the Agency conducted a landmark study
of PM emissions, testing nearly 500 gasoline-fueled light'duty cars and trucks in Kansas
City, Missouri. Due to the technical difficulties associated with measuring PM emissions,
the Kansas City study - a collaborative effort including EPA, DOT, the Department of
Energy (DOE), and the automotive and petroleum industries - is currently the largest
such study ever conducted. The Kansas City study confirmed that PM emissions from
light-duty gasoline-fueled vehicles are higher than earlier predicted, and clearly showed
that cold ambient temperatures can dramatically increase PM start emissions. The
MOVES2010 model includes these increases in PM start emissions at low temperatures,
EPA's understanding of emissions from heavy-duty vehicles has continued to improve
since MOBILE6.2 was issued. Most earlier heavy-duty emission rates were based on
certification tests of then-new, mid-1990's engines. For MOVES2010, EPA has been
able to analyze data on more than 400 in-use trucks, some in the laboratory and some
with on-road measurement equipment. This allowed the Agency to understand how
real trucks pollute at a range of speeds and driving conditions. EPA also has been able
to better incorporate emissions from heavy-duty diesel crankcase ventilation and from
extended idling (also known as "hotelling") - two emission processes that were relatively
unstudied at the time MOBILE6.2 was developed. The incorporation of this additional
data accounts for the increases in heavy-duty NOx and PM emissions reflected in
MOVES2010. Emission differences in MOVES2010 are especially large for heavy-duty
PM emissions because they reflect updated data on the effects of both speed and vehicle
deterioration not previously available.
Q13. How are the changes in MOVES2010 expected to affect I/M program credit?
A13. In moving from MOBILE6.2 to MOVES2010 users will notice that the emission reductions
estimated for individual I/M programs have gone down significantly between the two
models. The magnitude of the difference depends upon the criteria pollutant and evaluation
year being considered, the design of the I/M program, and local variables, such as fuel
composition, average temperature, and the age distribution of the in-use fleet. The main
reason for this reduced credit is the continuation of a previously observed trend toward
improved, in-use vehicle durability first seen in MOBILE6.2 which is continued for
MOVES2010. This is a "good news" story for the environment because it means that in-use,
light-duty vehicles are continuing to stay cleaner longer than was previously thought to
be the case. One side-effect of the continuation of this trend is that I/M programs (which
reduce emissions by identifying cars in need of repair and getting them fixed) will continue
to achieve less SIP credit than previously projected because there are fewer and fewer
vehicles in need of repair than originally projected,
As part of its testing of MOVES2010, EPA modeled a typical I/M program including
onboard diagnostic (OBD) testing on model year (MY) 1996 and newer vehicles and a
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loaded-mode tailpipe test on MY1995 and older vehicles; this program was modeled for
a 2008 evaluation year using both MOBILE6.2 and MOVES2010. For VOC and NOx,
MOBILE6.2 estimated emission reductions from this I/M program of roughly 12% and
17% respectively compared to the no I/M case while MOVES2010 estimated reductions
of approximately 5% and 10% from the same I/M program compared to the no I/M case.
In other words, for a typical I/M program in 2008, MOVES2010 estimated approxi-
mately 40-60% fewer reductions than originally projected by MOBILE6.2. The difference
between the two models only grows as a user models later evaluation years because while
MOBILE6.2 projects a steady increase in percent I/M reductions for both VOC and NOx,
MOVES2010 estimates a relatively constant 5% reduction in VOCs from I/M from 2008
through 2020, while it projects that NOx reductions from I/M drop from approximately
10% in 2008 to 6% in 2020. It should be noted, however, that this comparison is for
illustration purposes only. As indicated above, the results for individual I/M program
areas will vary significantly due to local variables, such as the design of the I/M program,
local fuel composition, average temperature, and the age distribution of the in-use fleet.
Q14. How are the changes in emission rates in MOVES2010 expected to affect attainment
demonstrations?
A14. The answer to this question depends upon the unique circumstances of each nonattainment
or maintenance area. The emission comparisons depend very heavily on the pollutants
of concern, the dates of concern, and on existing local control measures, traffic patterns,
fleet age, and the mix of cars and trucks. In some cases, a change from MOBILE6.2 to
MOVES2010 may result in increased emissions estimates, while in other cases it may
result in decreased emissions estimates for various time periods.
Moreover, because of the complex chemistry and meteorology involved in air pollution,
the implications of changes in highway vehicle emissions may not be clear until multiple
years are examined and the new emissions levels are applied in an air quality model.
Relative differences in emissions over time from MOBILE6.2 to MOVES2010 may be as
important as, or more important than, differences between the two models in any one
year. Therefore, MOVES2010 users should not immediately assume that increases or
decreases in emissions in any single year imply the need for more or fewer SIP control
measures until those changes in emissions have been put in the complete SIP context.
When considering how the transition from MOBILE6.2 to MOVES2010 may affect
attainment demonstrations, the relative reduction in emissions between a base year and
an attainment year is often more important than absolute increases or decreases in emissions.
To give users an illustration of how transitioning to MOVES2010 could potentially affect
such demonstrations, EPA has performed a comparison of MOVES2010 to MOBILE6.2
using local data for several different urban counties, varying the local data used by fleet
age distribution, fraction of light- and heavy-duty VMT, local fuel specifications, meteo-
rology, and other input factors. This preliminary comparison indicates significantly larger
relative reductions in PM2.5 using MOVES2010 compared to MOBILE6.2 for all of the
urban areas modeled and lower relative reductions of NOx. For VOCs, the results are
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mixed, with MOVES2010 projecting higher relative reductions of VOCs in two out of
three urban areas modeled, but lower relative reductions in at least one area. As the results
for VOCs highlight, results will vary based on local inputs in a given nonattainment area,
with local variations in fleet age distribution and composition having a significant influence
on the final results.
An increase in emissions due to the use of MOVES2010 may affect an area's ability to
demonstrate conformity for their transportation plan and/or transportation improvement
program. Areas are encouraged, through the interagency consultation process, to consider
if and how MOVES2010 may impact their future conformity determinations and discuss
any concerns with the appropriate EPA Regional Office,
Q15. What do users need to know to run MOVES2010?
A15. Users who have participated in the MOVES training offered jointly by EPA and
FHWA or who have practical experience with running the model in the form of Draft
MOVES2009 will find that, although some new features have been added, their experience
will apply well to using the official MOVES2010. In addition, EPA plans to work with
FHWA to offer another round of training in support of the release of MOVES2010,
including both on-site and webinar-based training. Information concerning these additional
training opportunities will be posted on EPA's mobile source model web page at
www.epa.gov/otaq/models/moves/index.htm as they are scheduled.
Concerning other recommended training, knowledge of the MySQL database query
language is not necessary for simple runs, but it will give users greater flexibility to
customize MOVES2010 outputs to meet their needs. For more advanced analyses such as
official SIP and/or conformity submissions, it is highly recommended that modelers develop
in-house MySQL skills as soon as possible. MySQL training is commercially available
from a variety of vendors.
Q16. What are the minimum system requirements for running MOVES2010?
A16. EPA recommends the following minimum system specifications for running
MOVES2010: processor - dual-core; memory - 1 GB RAM; storage - 40 GB; operating
system: Windows XP or higher. As is often the case when running resource-intensive
applications, a faster processor and more memory will allow MOVES2010 to perform user
runs more quickly. See the "MOVES2010 User Guide" posted at http://www.epa.gov/
otaq/models/moves/index.htm for more details on MOVES system requirements.
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