In 1990 the California Air Resources Board (CARB) adopted a future Zero Emissions Vehicle (ZEV) requirement to increase air quality standards. Under this regulation, CARB required automotive manufacturers to offer ZEVs. CARB initially required that 2% of vehicles sold in California from large manufacturers in 1998 had to be ZEVs. Manufacturers that sold more cars in California had to make more ZEVs. Since 1990, the regulation has been modified to account for technological advancement. CARB reviews this regulation every other year. This regulation accelerated automotive manufacturers in designing and building ZEVs and transitional ZEVs. California uses a credit system to calculate compliance. The credits are based on the vehicles electric range. Some ZEVs use hydrogen fuel cells. Gas-electric hybrids also receive a credit amount. If a vehicle has a longer electric range, the manufacturer receives more credits toward compliance. In the 1990s, manufacturers began to produce “Compliance Cars” to help meet the ZEV requirement. Other states can join California and adopt the same standards or follow the federal guidelines. Nine states follow California’s ZEV regulations: Connecticut, Maine, Maryland, Massachusetts, New York, New Jersey, Oregon, Rhode Island and Vermont. Go to arb.ca.gov to learn more about the ZEV program.