Three different methods for measuring the use of safety belts in cars were tested for accuracy, efficiency and cost. Drivers who had to stop for traffic signals at junctions or at exits of motorways were given a card which they were asked to fill in and return afterwards. The person giving the card looked inside the car to see if the belt was used or not. A third person registered the number of the licence plate from a distance and registered also the use of belts as far as he could see. The surveillance inside the car was the most effective. In 92% of the observations the presence and the use of seat belts in the driver's seat could be established and for the place beside the driver the presence and use of seat belts was established in 77% of the observations.
Abstract