Abstract
The study presents empirical evidence of accident risk during and following rain events in the cities of Calgary and Edmonton, Canada. The matched sample approach is used to examine data for 169 rain events and over 15, 000 accidents that occurred during the years 1979-1983. The overall accident risk during rainfall conditions was found to be 70% higher than normal. The data suggest that accident risk returns to normal as soon as the rainfall has ended, despite the lingering effects of wet road conditions. (A)