Impaired driving: how effective are Canada’s impaired driving laws

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University of New Brunswick


Impaired driving has been a major cause of death and injuries in Canada for decades, and in response a succession of laws has been put in place to reduce cases of impaired driving. This report evaluates the effectiveness of a number of recent changes to impaired laws using econometric methods applied to a Census Metropolitan Area (CMA) level dataset over a 12-year period and makes recommendations about what approaches might be introduced in the future to reduce the cases of impaired driving. Results indicated that after controlling for changes in demographic, socioeconomic and geographic characteristics, as well as a secular trend in reduction in incidence over time, measures enacted to reduce the blood alcohol content level before charges applied and the duration of license suspension had no appreciable effect on the incidence of impaired driving. In addition, results indicated that police concentration appeared to have a positive effect on impaired driving incidence, likely indicating an increase in detection rather than any changes in underlying driver behavior.