Abstract
In-depth accident investigation programs were conducted specifically to collect data for evaluation of the efficacy of the 1974 and 1975 restraint systems. Stratified random sampling techniques were used to collect data on 1973- 1975. American passenger cars in towaway accidents. Occupants of 1974 cars used restraints more frequently than occupants of 1973 cars. Use of full restraints by these occupants increased by a factor of eight over their use in 1973 cars. Use of full restraint in 1975 cars was lower than in 1974's, but still more than seven times as great as in 1973 cars.