From the mid-1960s onwards, rapid economic growth and progress in motorization began to take their toll in the form of air pollution and rising traffic accident numbers. Following the introduction of the 1971 Muskie Act in the U.S., Japan adopted similar emission control measures. These regulations were so stringent that many considered them unenforceable, but the Honda Civic with its CVCC engine managed to clear the new standards in 1973, ahead of any of its rivals worldwide.