The object of this study is to evaluate the effect of Antilock Braking System (ABS) as a preventive safety device by statistical analysis of integrated road traffic accident database.

The road traffic accident data including driver and road environment condition and the registered vehicle data including safety device were integrated. The risk of being struck from behind while stopping is not influenced by the driver characteristic of the struck vehicle. So the number of those vehicles/drivers is able to be considered a quasi-induced exposure, and the relative accident rates for some combinations of 7 factors listed later were calculated. Data of 253,035 cars, which were involved in a traffic accident from the year 2002 to 2007, manufactured from the year 1993 to 2000 and driven by a sober, private purpose and seat-belted driver, were analyzed by 7 factors;​ sex and age of driver, types of collisions, day/night, road surface condition, with/without a passenger and with/without ABS. ABS is expected to reduce the accident rate, especially for some collision types which could be prevented by keeping wheels unlocked.

The results shows;​ 1) the accident reduction effect of ABS on wet road surface was greater than on dry road surface, and 2) ABS reduced the relative accident rates of a rear-end collision by 1-38% and an single vehicle collision by 10-33%.

There are several discussions about the validity of the quasi-induced exposure method. But the effect of ABS was confirmed by considering the interactive effect with other factors such as age of driver or with/without a passenger. Further studies are required for precise discussion. The developed integrated database and the proposed method are also useful to evaluate other preventive safety devices