Section 176(c) of the Clean Air Act of 1977 (42 U.S.C. 7506(c)) requires transportation planning agencies in air quality non-attainment and maintenance areas to demonstrate air pollutant emissions from federally supported MTPs and TIPs conform to the State Implementation Plan (SIP). Since Vigo County was a designated a maintenance area for ozone under the 1997 National Ambient Air Quality Standard (NAASQ), the MPO was required to make an air quality conforimity determination in support of the 2045 MTP and the FY 2024-2028 TIP. These determinations, which were approved by the Federal Transit Administration and the Federal Highway Administration, were made in accordance with 40 CFR Parts 51.390 and 93.