Federal Clean Air Act Amendments of 1990 - Landmark federal legislation Congress that renews the federal Clean Air Act and makes significant program changes. For the transportation sector, changes include a definition of conformity and requirements for formulation by EPA and DOT of conformity regulations, and requirements for the use and development of clean-fueled vehicles.

Federal Clean Air Act. A federal law passed in 1970 and amended in 1977 and 1990 which forms the basis for the national air pollution control effort. Basic elements of the act include national ambient air quality standards for major air pollutants, air toxics standards, acid rain control measures, and enforcement provisions.