Conformity means a Clean Air Act (42 U.S.C. 7506) requirement that ensures that Federal funding and approval are given to transportation plans, programs and projects that are consistent with the air quality goals established by a State Implementation Plan (SIP). Conformity to the purpose of the SIP means that transportation activities will not cause new air quality violations, worsen existing violations, or delay timely attainment of the NAAQS or any required interim emission reductions or other milestones in any nonattainment or maintenance area. The transportation conformity regulations (40 CFR part 93, subpart A) sets forth policy, criteria, and procedures for demonstrating and assuring conformity of transportation activities.
23 CFR § 450.104
Unless otherwise specified, the definitions in 23 U.S.C. 101 and 49 U.S.C. 5302 are applicable to this part.