Are school zones effective in reducing speeds and improving safety?

Abstract

This paper describes a study undertaken to assess the speed and safety effects of reducing speed limits from 50 to 30 km/h in school zones. Mean speeds and 85th percentile speeds were reduced by 12.2 and 11.6 km/h, respectively. Speed variation was also reduced, and the speed cumulative distributions shifted to the left, indicating further reductions for all speed ranges. The safety evaluation results revealed fatal and injury collisions were significantly reduced by 45.3% and injuries to vulnerable road users were reduced by 55.3%. In fact, for every 1 km/h reduction in mean speed, fatal and injury crashes were reduced by about 4%, which is consistent with findings from previous research. Neither spatial nor temporal collision migration or spillover effects were significant factors in the analysis. Consequently, the results of this study provide strong evidence that reducing speed limits to 30 km/h in school zones can bring significant safety benefits by reducing vehicular speeds and fatal and injury crashes.