A comparison of recent crash fatality trends in Canada and the United States: Why do they differ?

This study examined the divergence in traffic fatality trends between the United States and Canada from 2007 to 2021. While U.S. fatalities began increasing after 2011, Canada maintained a declining trend.

Using data on traffic fatalities and several variables related to travel exposure, demographics, and risk, we analyzed trends for both total and crash-type-specific fatalities. We sought to identify which crash types are primarily responsible for the trends and what risk factors may explain these trends. In both the United States and Canada, several common factors were identified, with the trends being in the opposite direction. These common factors included pedestrian and cyclist fatalities, and alcohol-involved, speeding-related, and truck-involved fatalities.

When accounting for exposure by looking at the rate of traffic fatalities per 100 million vehicle miles traveled (MVMT), it appeared that in the United States, a significant amount of the differences in traffic fatalities over time was explained by variations in MVMT, indicating that the level of risk was relatively stable. Conversely, in Canada, the rate of traffic fatalities to MVMT consistently decreased, indicating that other risk factors had decreased. Statistical models confirmed that population and vehicle miles traveled have a positive association with the number of fatalities.

Depending on the crash type, gross domestic product per capita and the unemployment rate, variables that influence MVMT, were additional significant exposure-related variables. The models also indicated that part of the difference in fatality trends may be due to Canada's more substantive and common laws related to driver distraction, seat belt use, and the use of speed safety cameras.