Impact of Canada’s Cannabis Act on drug- and alcohol-related collisions in Québec: an interrupted time-series analysis of five major cities

The findings suggest that increased cannabis availability, as measured by cannabis sales, is associated with higher rates of both drug- and alcohol-related crashes, particularly in Montréal and Longueuil. These results support the hypothesis that changes in cannabis availability may influence two distinct impaired driving patterns, highlighting the need for region-specific road safety interventions.