Investigators affiliated with the University of Minnesota examined the association between cannabis legalization laws and fatal motor vehicle crash rates (both pedestrian-involved and total fatal crashes) during the years 1991 to 2018. Motor vehicle accident trends in Colorado, Oregon, and Washington were compared to trends in five control states.
Authors failed to identify any uptick in pedestrian-involved fatal motor vehicle crashes that could be attributable to the enactment of marijuana legalization. They further acknowledged that two of the three states they examined, Washington and Oregon “saw immediate decreases in all fatal crashes following medical cannabis legalization.”
They concluded, “Overall, these findings do not suggest an elevated risk of motor vehicle crashes associated with cannabis legalization, nor do they suggest an increased risk of pedestrian-involved motor vehicle crashes.”
The study’s findings are consistent with those of others, such as those here and here, reporting decreases in incidences of fatal motor vehicle accidents following the enactment of medical marijuana legalization. Other studies assessing the impact of adult-use retail sales on traffic safety have yielded more mixed results.
Full text of the study, “An examination of relationships between cannabis legalization and fatal motor vehicle and pedestrian-involved crashes,” appears in Traffic Injury Prevention. Additional information is available from the NORML fact sheet, “Marijuana and Psychomotor Performance.”