Ottawa, Canada: Adult-use marijuana legalization is not associated with statistically significant increases in fatal motor vehicle accidents, according to an analysis of Canadian crash data published by representatives of the Traffic Injury Research Foundation and the Institute for Highway Safety.
Researchers assessed trends in motor vehicle crash frequency prior to and following Canada’s decision in 2018 to legalize and regulate the adult-use marijuana market.
They reported: “For fatal and injury crashes, the time-series analysis found no statistically significant impact while the before-after method found a statistically significant decrease of 3.9 percent.”
With respect to non-fatal vehicle crashes, researchers “found limited evidence of a large-scale impact of legalization on crash frequency.”
The findings are consistent with those of a prior Canadian study determining that the enactment of adult-use marijuana sales is not associated with any increase in motor vehicle injuries requiring hospitalization.
Findings from US states have yielded less consistent results, with some jurisdictions experiencing an increase in motor vehicle crashes and others experiencing no changes attributable to cannabis legalization.
Full text of the study, “Evaluating the road safety impacts of recreational cannabis legalization in Canada,” is available from SSRN. Additional information is available from the NORML Fact Sheet, ‘Marijuana and Psychomotor Performance.’