A new study released last week has found that legalizing either medical marijuana or cannabis for recreational use is not associated with an increase in traffic fatalities that involve pedestrians. A report on the study, “An examination of relationships between cannabis legalization and fatal motor vehicle and pedestrian-involved crashes,” was published on Friday in the journal Traffic Injury Prevention.
In a statement of the study’s objectives, investigators associated with the University of Minnesota explained the rationale for their research.
“While attention has been given to how legalization of recreational cannabis affects traffic crash rates, there has been limited research on how cannabis affects pedestrians involved in traffic crashes,” they wrote. “This study examined the association between cannabis legalization (medical, recreational use, and recreational sales) and fatal motor vehicle crash rates (both pedestrian-involved and total fatal crashes).”
To conduct the study, the team of researchers investigated the association between laws legalizing cannabis and fatal motor vehicle crash rates, including both pedestrian-involved and fatal vehicle collisions. Motor vehicle accidents in three states with legal cannabis—Oregon, Washington, and Colorado—were compared to the trends in five control states. The investigators were unable to identify any increase in fatal motor vehicle accidents that could be attributed to the adoption of policies that legalized cannabis.
“We found no significant differences in pedestrian-involved fatal motor vehicle crashes between legalized cannabis states and control states following medical or recreational cannabis legalization,” the researchers wrote in the results of the study.
More Than 25 Years Of Crash Data Analyzed
The investigators used crash data from the Fatality Analysis Reporting System (FARS) to calculate monthly rates of fatal motor vehicle crashes and fatal pedestrian-involved crashes per 100,000 people from 1991 to 2018. Changes in monthly crash rates in the three states that had legalized cannabis were compared to matched control states using segmented regression with autoregressive terms.
Both Washington and Oregon saw immediate decreases in all fatal crashes following the legalization of cannabis for medicinal purposes. Colorado showed an increase in trend for all fatal crashes after cannabis was legalized for use by adults and the beginning of recreational sales in 2014.
“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 authors of the study wrote in their conclusion.
In a press release about the study, the National Organization for the Reform of Marijuana Laws (NORML) noted that the results of the research are consistent with those of similar studies. In a study published last year, a team of investigators from the University of California at Irvine determined that the legalization of medical marijuana in California was associated with a sustained decline in traffic fatalities. And in 2016, investigators with Columbia University in New York and the University of California at Davis found that the legalization of medical marijuana is associated with a reduction of traffic fatalities among younger drivers.