University of California Transportation Center

Improving air quality has long been a big concern for society. The original Clean Air Act was signed by president Nixon in 1970 in accordance to national clamor for environmental healing. In 1990, president Bush signed the Clean Air bill which made significant revisions tot he original Clean Air Act. The Clean Air Act Amendments of 1990 establishes tighter pollution standards for emissions from automobiles and trucks. The new law also allows stricter emission limits for vehicles in California which can be met with any combination of vehicle technology and cleaner fuels. As a result, in the 1990s, California passed a law which mandates the introduction and sale of low-emission vehicles (e.g. natural gas vehicles) and zero-emission vehicles (e.g. electric vehicles). According to the levels set by California Air Resources Board, 10% of all vehicles sold in California must be electric vehicles by year 2003. Moreover, other states are actually considering following California's lead and adopting similar policies and incentive programs.