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Transportation Conformity Highlights

December 2007

Prepared by the Office of Natural and Human Environment Federal Highway Administration

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EPA Releases Final Conformity Rule. On January 24 the final transportation conformity rule which implements the Clean Air Act amendments adopted in 2005 under the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) was published in the Federal Register. The SAFETEA-LU changes have been implemented through a joint EPA-DOT interim guidance issued on February 14, 2006. This final rule replaces the interim guidance. For further information and a copy of the rule, see: The rule is effective on February 25, 2008.

EPA Releases EMFAC2007 Motor Vehicle Emission Factor Model for California.On January 18, EPA posted a notice in the Federal Register approving California's updated EMFAC model, EMFAC2007. This model is only used in California and all new regional emissions analyses and CO hot-spot analyses started after April 18, 2008 must use the new model. For more information, see:

Court Rules in Favor of EPA on Most Challenges to EPA's PM Conformity Hot Spot Regulations -- Asks EPA to Further Explain One Provision. On December 11, 2007 the D.C. Circuit Court of Appeals issued its ruling on a challenge to EPA's transportation conformity "hot-spot" regulations for particulate matter (PM). The regulations, issued by EPA in March 2006, require that transportation projects conform at the local level to the State Implementation Plan (SIP) in PM-10 and PM-2.5 nonattainment and maintenance areas. The court remanded the rule to EPA to further explain its interpretation of the Clean Air Act provision that requires that transportation projects do not delay timely attainment of any standard or any required interim milestone in any area, and how the rule satisfies those provisions. The court ruled in favor of EPA on all other challenges to the rule. (Environmental Defense v. EPA, D.C. Cir., No 06-1164, 12/11/07).

Training Opportunities

NTI Introduction to Transportation Conformity Course.All four sessions of the the Introduction to Transportation Conformity course were delivered for the current NTI fiscal year, which ends on June 30, 2008. Future training schedule will be available at later this year.

FHWA Resource Center Training Activities. FHWA's Resource Center Air Quality Technical Services Team is available to offer air quality-related training opportunities and information is available at: For further information, contact: Mike Roberts at 404-562-3928 or at

If you have any suggestions for future monthly conformity highlights, please email:

FHWA Resource Center Air Quality Team Contacts:

Updated: 10/20/2015
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