Statistical Evaluation of Brake Safety Improvements for Passenger Cars

Statistical analyses were used to evaluate the safety effects of dual master cylinders, front disc brakes, and the brake modifications in passenger cars that were associated with the version of Federal Motor Vehicle Safety Standard 105 that took effect on January 1, 1976. Regression analyses of accident data associated substantial and statistically significant reductions in brake failure accidents with dual master cylinders. Similar analyses associated a modest but statistically significant reduction in brake failure accidents with front disc brakes, but no significant reduction in other types of accidents. Stopping tests with new and used cars showed modest reductions in stopping distance for 1978 cars (built after the 1/1/76 version of the brake standard took effect) relative to 1973 (pre-standard) cars.

This paper presents the views of the author and not necessarily those of the National Highway Traffic Safety Administration (NHTSA).