Regulatory Announcement

EPA Finalizes Transportation 

Conformity Rule: MOVES Regional 

Grace Period Extension 

EPA is taking final action to extend the grace period an additional 

year before the MOtor Vehicle Emission Simulator model 

(MOVES) is required for regional emissions analyses for transportation conformity determinations (“regional conformity analyses”). 

MOVES1

 is EPA’s state-of-the-art model for estimating emissions 

from highway vehicles, based on analyses of millions of emission test 

results and considerable advances in the Agency’s understanding of 

vehicle emissions. 

This final rule ensures that air quality is protected and clarifies requirements for 

implementers under the extended grace period for regional conformity analyses. 

EPA has worked closely with the U.S. Department of Transportation to develop this 

final rule. 

Background 

Transportation conformity is a Clean Air Act requirement that ensures that federally supported highway and transit projects are consistent with state air quality 

implementation plans (SIPs). Conformity helps protect public health through early 

consideration of the air quality impacts of transportation decisions in places where 

air quality does not currently meet federal National Ambient Air Quality Standards 

(NAAQS) or has not met them in the past. 

1 EPA notes that any reference to “MOVES” in this Fact Sheet refers to the approved version of 

MOVES2010 and subsequent minor revision (e.g., MOVES2010a). EPA will note at the time of a 

future model release whether an aproved model is a minor revision to MOVES2010. 

Office of Transportation and Air Quality 

EPA-420-F-12-002 

February 2012 
Regulatory Announcement

Key Elements of the Final Rule 

•	 This rule provides an additional year to the previously established two-year conformity 

grace period. As a result, MOVES is not required for new regional conformity analyses 

after March 2, 2013. 

•	 This final rule is based on unique circumstances presented by the transition to MOVES 

from the previous emissions model. Several state and local transportation and air quality 

agencies have requested additional transition time for using MOVES in regional conformity 

analyses, due to the significant software, operational and technical differences between 

MOVES and the previous emissions model, MOBILE. 

•	 This action does not affect EPA’s previous approval of the use of MOVES in official SIP 

submissions or the existing grace period before MOVES is required for carbon monoxide 

and particulate matter hot-spot analyses for project-level conformity determinations 

(75 FR 79370). 

Health and Environmental Benefits 

The final rule ensures that transportation activities are consistent with air quality goals of the 

transportation conformity program. The final rule ensures that all nonattainment and maintenance 

areas use conformity tests that ensure air quality progress continues in areas that need to attain 

or maintain the NAAQS. 

For More Information 

You can access documents on transportation conformity on EPA’s Office of Transportation and 

Air Quality Web site at: 

www.epa.gov/otaq/stateresources/transconf/index.htm 

For further information on this final rule, please contact: 

Meg Patulski 

U.S. Environmental Protection Agency
 

Office of Transportation and Air Quality
 

2000 Traverwood Drive
 

Ann Arbor, MI 48105
 

734-214-4842
 

E-mail: patulski.meg@epa.gov
 

Or 

Astrid Larsen 

U.S. Environmental Protection Agency
 

Office of Transportation and Air Quality
 

2000 Traverwood Drive
 

Ann Arbor, MI 48105
 

734-214-4812
 

E-mail: larsen.astrid@epa.gov
 

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