The Tennessee Child Passenger Protection Act, mandating the use of child restraint devices for children younger than 4 years, took effect in 1978. In the years 1978 through 1983, eighty-one children younger than 4 years died in Tennessee traffic accidents; only two were in child restraint devices. During this period, as child restraint device use rose from 8% to more than 30%, the number of deaths among children younger than 4 years declined more than 50%. Analysis of supplemental accident reports filed in investigations of motor vehicle accidents involving children younger than 4 years during 1982 and 1983 showed that child restraint devices are highly effective in preventing death and in preventing or reducing injury. Children not in child restraint devices were 11 times more likely to die in an accident than children in child restraint devices. Children traveling in the arms of an adult were exposed to a risk of injury or death comparable to that of children left entirely unrestrained.