Samenvatting
Lap and shoulder belts were in use by 44% of drivers of 1974 interlock equipped cars compared to 8% use in 1973 buzzer-light equipped cars, based on observations in three cities. In spite of the interlock system, however, nearly 47% of the drivers in the 1974 vehicles were not using belts. Belt use was significantly higher in cars produced by General Motors and Chrysler than in the cars manufactured by Ford and Volkswagen.