Abstract
The problems of making quantitative assessments of the effectiveness of vehicle safety design changes are discussed. In the area of active safety changes, where vision requirements, brakes, tyres, handling and ergonomic factors are concern, there appears to be an almost total absence of field studies aimed at measuring effectiveness. In the passive safety area a greater number of studies have been performed which demonstrate the success of seat belts, antiburst latches, head restraints and laminated windscreen glass.