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Current Law, Regulations and Guidance for State and Local Transportation

  • Clean Air Act - Conformity Section (PDF) (from pp 111 to pp 116, 6 pp, 180 K, About PDF)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.
  • Transportation Conformity Regulations (PDF) (42 pp, 288 K, EPA-420-B-12-013, April 2012, About PDF) 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.
  • 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.
  • 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.
  • 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 Astrid Terry at 734-214-4812 or