Does the inclusion of vehicle impoundment in provincial short-term administrative driver’s license suspension programs reduce total and alcohol-related fatal collisions in Canada?

Abstract

Objectives: To determine (1) whether the implementation of vehicle impoundment as part of provincial short-term administrative driver licensing suspension (ADLS) programs significantly reduced total and alcohol-related collision fatalities, and (2) if provinces with vehicle impoundment as part of their short-term ADLS programs see greater reductions in total and alcohol-related fatal collisions when compared to provinces without a vehicle impoundment law.

Methods: Data on monthly total and alcohol-related fatal collisions from January 2005 to December 2016 are drawn from British Columbia (BC), Alberta (AB), Saskatchewan (SK), Manitoba (MB) and Ontario (ON). Changepoint time series analysis of fatal crashes is employed to detect within-province differences after implementing short-term impoundment programs, and between province differences comparing provinces with short-term impoundment programs (BC, introduced October 2010; AB, introduced July 2012; and SK, introduced July 2014) and those without (ON and MB). Outcome measures are the monthly per capita total and alcohol-related fatal collisions.

Results: A significant reduction in per-capita alcohol-related fatal crashes was observed in British Columbia (−47.4%) in the period following the adoption of vehicle impoundment in their short-term ADLS. A significant decrease was also observed in Alberta (−37.5%), though this trend began prior to policy change; no significant effect was observed in per capita alcohol-related fatal crashes rates in Saskatchewan (−6.1%) in the two years following the introduction of vehicle impoundment. Ontario and Manitoba, two provinces without mandatory vehicle impoundment laws, also experienced significant reductions in per-capita alcohol-related fatal crashes between 2005 and 2016 (−36.4% and −35%, respectively).

Conclusions: While mandatory vehicle impoundment programs for driving in the “warn” range (0.05%–0.08% BAC) have shown success in reducing fatal crashes in British Columbia, similar reductions in two other provinces with short-term vehicle impoundment were not observed. Moreover, large reductions in fatal crashes were observed in two provinces without vehicle impoundment as part of their short-term ADLS programs. Collectively, these findings suggest that vehicle impoundment, alone, has limited impact on fatal crash rates and that other factors help to explain the observed trends. Further analysis of new vehicle impoundment programs is warranted.

Keywords:

• Vehicle impoundment
• fatal collisions
• alcohol-related collisions
• administrative driving license suspension
• time series

Disclosure statement

No potential conflict of interests was reported by the authors.

Data availability statement

Data is available from corresponding author upon request.