An examination by Quartz Media LLC challenges the notion that the legalization of cannabis at the state level is linked to an increase in traffic fatalities. Researchers from Quartz Advisors conducted an analysis focusing on four states—California, Maine, Massachusetts, and Nevada—that have legalized cannabis for adult use. To provide a comparative perspective, they also looked at five control states: Idaho, Indiana, Kansas, Nebraska, and Wyoming. The study covered the years 2016 to 2019, excluding 2020 and 2021 due to perceived anomalies resulting from a nationwide 19 percent spike in traffic fatalities.
Contrary to expectations, the analysis revealed that in the four states where cannabis was legalized, traffic fatalities decreased by an average of 12 percent in the three years following the implementation of adult-use marijuana legalization. In contrast, the control states experienced a nearly two percent increase in fatalities over the same period. Nationally, traffic fatalities decreased by 10.6 percent between 2016 and 2019.
The report emphasized that none of the four states that legalized cannabis in 2016 witnessed an increase in traffic fatality rates during the three-year period under examination. Three out of the four states even saw a significant decrease in vehicle deaths, with Massachusetts leading the way with a 28.6 percent reduction in the three years following legalization.
In summary, the analysis concluded that, despite valid concerns surrounding the debate on marijuana legalization, the impact on traffic safety should not be one of those concerns. Citing their research and that of others, the report suggests that fears regarding the correlation between legal marijuana and traffic safety may be unfounded.
The article also noted that previous studies on the association between adult-use cannabis legalization and motor vehicle accidents have produced inconsistent results. Some studies reported a slight increase in crash rates in specific states several years after legalization, while others found no such change.
Additionally, data from the Insurance Institute for Highway Safety in 2021 highlighted a wide disparity in traffic safety trends among states that legalized adult-use cannabis. Some jurisdictions experienced an increase in motor vehicle accidents, while others saw a significant decrease. This variability suggests that changes in marijuana policy alone are not reliable indicators of traffic safety trends.