Random breath testing (RBT) was introduced in New South Wales on December 17, 1982. Although there have been many studies of the impact of RBT, no comprehensive time-series analysis of accidents has ever been published. In this paper, daily accident data for the period January 1976 to December 1992 are analysed for the impact of RBT, controlling for weather information, road usage/economic indicators, "time" factors, and the .05 legislation introduced in December 1980. The initial effect of RBT on total fatal accidents was extremely marked, with a drop of 48 percent, an effect which was however limited to about two months' duration. The long-term effects of RBT were revealed most clearly for single-vehicle revealed most clearly for single-vehicle night-time accidents, for which the initial impact was a 24 percent decline that was sustained for nearly five years. In addition, there were an estimated 12 percent fewer such accidents for every 1,000 drivers tested, an effect which intensified as levels of RBT enforcement were increased from 1987 onwards. As predicted, there was almost no discernible impact of RBT on non- alcohol related accidents. The analyses strongly support the theoretical model of deterrence developed by Homel. (A)
Samenvatting