The influence of anti-lock braking systems (ABS) on relative crash risk is examined by comparing the ratio of the number of crashes under an adverse condition to the number of crashes under a normal condition. The study used seven General Motors passenger vehicles having ABS as standard equipment for 1992 models, but not available for 1991 models. As only relative risks are measured, conclusions are contingent on crucial assumptions. The following interpretations are largely consistent with the results of the present and earlier studies. (1) If we assume that ABS is associated with no difference in crash risk on dry roads, than the results imply that ABS reduces overall crash risk by (3 plus/minus 1)%. (2) If we assume that ABS risk by (3 plus/minus 1)%. (2) If we assume that ABS reduces crash risk on dry roads, the above estimate is increased by the assumed amount. (3) If we assume that drivers use some of the improved braking provided by ABS for benefits other than safety, such as slightly higher travel speeds, then we cannot estimate the overall effect on crash risk.
Samenvatting