Questions and Answers

EPA Releases MOVES2010 Mobile 

Source Emissions Model: 

Questions and Answers

Q1. What is MOVES2010?

A1. 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 emissions 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 

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) 

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 estimating GHG emissions in the transportation planning process should consider using 

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 2009, 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 Highway 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 available 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 development, 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 Preparation 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 fundamentally, it has been designed to do calculations with information in databases, using the 

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 gramsper-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 individual 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 capabilities 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 lightduty 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.

Q11. How do MOVES2010 emission estimates compare to those of MOBILE6.2?

A11. 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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counties, each with its own fleet age distribution, fraction of light- and heavy-duty vehicle 

miles travelled (VMT), local fuel specifications, meteorology, and other input factors. 

The differences between MOVES2010 and MOBILE6.2 found in this analysis are described 

below, by criteria pollutant. Actual results will vary based on local inputs in a given area, 

with local variations in the fleet age distribution and composition having a significant 

influence on the final results.

For volatile organic compounds (VOCs): For all the urban counties modeled, mobile 

source VOC emissions were lower using MOVES2010 than previously estimated using 

MOBILE6.2. This difference is most noticeable for Tier 1 and newer vehicles, especially 

for evaporative emissions.

For oxides of nitrogen (NOx): Emissions from both light- and heavy-duty trucks are higher 

than previously estimated. Using MOVES2010 and assuming no change in extended 

idle activity as a fraction of total activity, EPA projects that uncontrolled extended idle 

emissions from heavy-duty vehicles will become a significant share of the on-road mobile 

source NOx inventory in the future. In some urban areas of the country, in fact, extended 

idle emissions could comprise approximately one quarter of total heavy-duty NOx emissions 

by 2020. This increase in the fraction of overall emissions represented by idling emissions 

is due to the fact that new heavy-duty vehicle standards are driving down regular exhaust 

emissions, making the idle fraction bigger by comparison. 

For PM2.5: EPA’s estimate of mobile source PM2.5 emissions using MOVES2010 is significantly higher compared to MOBILE6.2 for both light- and heavy-duty vehicles and 

for all of the urban areas modeled. For passenger cars and light trucks, these increases are 

based on data developed as part of EPA’s Kansas City study, which showed much higher 

PM2.5 emissions at low ambient temperatures than previously known. For heavy-duty 

trucks, MOVES2010 incorporates new data from a large study of trucks conducted by the 

Coordinating Research Council (known as the CRC E-55 study) which includes deterioration effects on in-use emissions. MOVES2010 also models the impact of vehicle speed 

and load on PM emissions, showing very high rates of PM generation in stop-and-go 

traffic conditions. This high emission rate consists of the emissions produced while the 

engine is under increased load while accelerating (i.e., the “go” phase of stop-and-go driving) 

as well as the emissions produced while the vehicle is stopped and therefore not accumulating any mileage, thus resulting in higher overall emissions per total mile driven.

Q12. What sort of data did EPA use to improve its estimates of vehicle emissions?

A12. Over the last ten years, EPA’s in-use data about technologies such as Tier 2, secondgeneration onboard diagnostics (OBD II), and enhanced evaporative emission control 

systems have dramatically improved. For MOVES2010, EPA has been able to carefully 

study these newer technologies, examining millions of results for light-duty vehicles. A 

detailed analysis of 70,000 vehicles in Arizona’s I/M program provided information on 

how vehicles from the late-1990’s and early 2000’s age. Other I/M and remote sensing 

data and special purpose studies helped EPA to better understand trends in VOC, CO, 
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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 approximately 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, meteorology, 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.