An evaluation of the impact of daytime running lights on traffic safety in Canada

Abstract

Since December 1, 1989 all new cars sold in Canada were required to be equipped with daytime running lights (DRL). This policy was expected to reduce angle and opposing collision involvement by 10% to 20% by making cars more conspicuous, thereby increasing the window of opportunity within which drivers can react. A quasi-experimental comparative posttest design is used in this study to evaluate the impact of DRL legislation on the incidence of angle and opposing collisions for 1989 cars and 1990 cars in the 1991 calendar year. The results show that the combined incidence of the two types of collisions is reduced by 5.3% (p < .05), mainly due to a reduction in the incidence of opposing collisions (−15%; p < .05), rather than angle collisions (−2.5%; NS). An examination of each province reveals that only two small provinces display a statistically significant reduction in the incidence of opposing collisions and one province displays a statistically significant reduction in the incidence of angle collisions. The implications of these results are discussed in terms of their relevance for DRL policy theory, traffic safety, future research, and cost.