Transportation Conformity Regulations

Overview

Transportation conformity is required under the federal Clean Air Act Section 176© to ensure federally supported transportation activities conform to or are consistent with the purpose of the applicable air quality management plan or State Implementation Plan (SIP). The Transportation Conformity Regulations are found in 40 Code of Federal Regulation (CFR) Part 93. Provisions related to conformity SIPs are found in 40 CFR Section 51.390. SCAG’s Transportation Conformity Working Group serves as the primary forum for interagency consultation on all matters related to both regional and project-level transportation conformity to comply with federal transportation and air quality planning requirements and improve air quality in Southern California. 

Overview

Project-Level Conformity

The Transportation Conformity Working Group (TCWG) serves as the primary forum for interagency consultation on all matters related to both regional and project-level transportation conformity to comply with federal transportation and air quality planning requirements in the six-county SCAG region. The TCWG consists of staff representatives from FHWA, FTA, U.S. EPA, Caltrans Headquarters, Caltrans Districts, CARB, CTCs, air districts, and transit operators in the SCAG region. The group meets monthly on the fourth Tuesday of the month. 

Overview

Regional Conformity Determinations

Federal approvals of regional transportation conformity determinations for Regional Transportation Plan (RTP)/Federal Transportation Improvement Program (FTIP) and amendments from Federal Highway Administration/Federal Transit Administration (FHWA/FTA) may be provided electronically through the California Transportation Improvement Program System database, including federal approval date and federal approval letters. Federal approval letters will continue to be produced for project-level conformity determinations. 

Overview

Transportation Control Measures

Transportation Control Measures (TCMs) are identified by air quality management plans and implementation plans to reduce emissions or concentrations of air pollutants from transportation sources by reducing vehicle use, changing traffic flow, or congestion conditions.​​​ SCAG works closely with the CTCs and Caltrans to ensure timely implementation of committed TCM projects in the region. Substitution of individual TCMs follows the process specified in the federal Clean Air Act (CAA) section 176(c).