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NOTE: You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.

This page provides access to all transportation conformity regulations, including final rules and rulemakings currently in progress. It also provides access to guidance documents that have been issued to facilitate implementation of the conformity program.

Transportation Conformity:  Restructuring Amendments

This final rule restructures several sections of the existing transportation conformity rule so that the rule applies to any new or revised NAAQS EPA establishes.

The Environmental Protection Agency first posted this final rule on its website in February,following a February 16th signature by Administrator Lisa P. Jackson. The substance of the rule has not changed, but because the physical rule package was misplaced during the transfer to the Office of Federal Register (OFR) for publication, EPA has now provided OFR with a duplicate rule package and new signature page dated March 8, 2012.

EPA will consider the rule to have been signed on March 8, 2012, and will treat March 8 as the signature date for all purposes.

Transportation Conformity:  MOVES Regional Grace Period Extension

This final rule extends the grace period before the MOtor Vehicle Emission Simulator model (currently MOVES2010a) is required for regional emissions analyses for transportation conformity determinations (“regional conformity analyses”). This final rule provides an additional year to the previously established two-year conformity grace period, which is now extended to March 2, 2013.

Current Laws and Regulations

  • Transportation Conformity Regulations (PDF) (42 pp, 288K, EPA-420-B-12-013)  This document reflects all transportation conformity rulemakings promulgated by EPA as of April 13, 2012, including the Restructuring Amendments final rule and the MOVES Regional Grace Period Extension final rule.
  • Baseline Year for the Baseline Year Test (in 40 CFR 93.119) Refer to this page for a table showing the baseline year to be used for each NAAQS and the regulatory provision where it is found.
  • Clean Air Act - Conformity Section (PDF) (8 pp, 107K)  This document includes Clean Air Act Section 176(c) as amended by the 2005 transportation act known as “SAFETEA-LU". EPA is providing this document for informational purposes only.
  • Chronological List of Transportation Conformity Rulemakings  EPA has published rule amendments in the Federal Register since transportation conformity was enacted as part of the 1990 Clean Air Act. These rulemakings include preamble text explaining rule provisions that remain in effect today.
  • Policy and Technical Guidance  EPA and the U.S. Department of Transportation have issued a number of guidance documents that provide additional information on implementing the conformity regulations.

For more information, contact Meg Patulski at 734-214-4842 or patulski.meg@epa.gov.

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