This document approves a revision to the New Mexico State Implementation Plan (SIP) for the Albuquerque/Bernalillo County nonattainment area that contains transportation conformity rules. The transportation conformity SIP revision enables the Albuquerque/ Bernalillo County Air Quality Control Board to implement and enforce the Federal transportation conformity requirements at the local level in accordance with 40 CFR part 51, subpart T--Conformity to State or Federal Implementation Plans of Transportation Plans, Programs, and Projects Developed, Funded or Approved Under Title 23 U.S.C. or the Federal Transit Act. The final approval action is limited only to 40 CFR part 51, subpart T (Transportation Conformity), and the SIP revision submitted under 40 CFR part 51, subpart W, conformity of general Federal actions, will be addressed in a separate document. The EPA is approving this SIP revision under section 110(k) of the Clean Air Act (CAA). The rationale for the approval action and other information are provided in this document.