Clean Air Act and Other States
Under the federal Clean Air Act, other states have a choice of either following the federal emissions standards or adopting California’s stricter standards; the law allows for only two standards — the federal rules or California’s rules.
Other States
When it comes to clean cars, states have led the way. Between 2005 and 2010, 14 states plus the District of Columbia adopted California’s more stringent standards, together representing about 40 percent of the new vehicle sales market. With so much state support for the stronger standards, it made sense for the federal government in 2009 to announce it would follow California’s and the states’ lead, adopting national rules that attain equivalent emissions reductions by 2016, and ensuring that all Americans have a choice of cleaner, more efficient cars that will save them money over the vehicle’s lifetime. The new federal standards were finalized in April 2010.