Samenvatting
The research is intended to measure the effectiveness of the interlock system in increasing safety belt usage. Therefore three separate studies were conducted: (1) among rental car customers at U.S. airports in order to obtain a large body of data early in the 1974 model year; (2) among rental car customers at Toronto International Airport, where different types of use-inducing systems could be studied; and (3) among owners of private cars in the general population of vehicles in 19 U.S. cities.