According to a new study conducted by Quartz Advisors, states that legalized marijuana in 2016 experienced a noticeable decline in traffic fatalities in the years that followed.
“In California, Maine, Massachusetts, and Nevada – four states that fully legalized marijuana in 2016 – traffic fatalities declined or remained the same in the three years that followed, compared to a slight increase in states where it remained illegal”, states the new study. In addition, a “comprehensive study of traffic data in the U.S. and Canada failed to find a statistically significant change in accidents and fatalities after legalization.”
Alcohol, on the other hands, “remains fully legal in all 50 states and D.C., is a factor in nearly a third of all automotive fatalities.”
Researchers found that “the traffic fatality rate did not increase in any of the four states that legalized in 2016 during that three-year period. Three of the four states saw a significant decrease in vehicle deaths over that span, while the rate in Maine showed no change.”
Massachusetts saw the biggest drop, as rates fell 28.6% in the three years following legalization.
For the study researchers “studied car accident data in states throughout the country before and after they legalized marijuana to see if legalization correlated with higher accident rates. We also spoke to state officials to gain their perspective on the effects of legalization on their roads.”
For “clarity and consistency”, researchers chose four states – California, Maine, Massachusetts, and Nevada – that fully legalized marijuana in 2016 to study vehicle death rate trends. They used deaths per 100,000,000 vehicle miles as our primary metric, sourced from the National Safety Council (NSC).
“Our team examined individual vehicle death rates and aggregated fatality rates in these four states during the years following 2016 and compared them to the U.S. national average. We also compared these numbers with those of Idaho, Indiana, Kansas, Nebraska, and Wyoming – five states that have not legalized marijuana”, states the study. “While the evidence put forth by this data is not meant to be conclusive about the effects of marijuana legalization on road safety, it does provide a degree of insight into the relationship between the two.”
The study found that the average traffic fatality rate for the U.S. as a whole fell by 10.6% between 2016 and 2019, whereas in states that legalized cannabis in 2016, “vehicle death rates fell at a slightly higher rate of 11.6%. States that have not legalized saw a slight increase of 1.7% from 2016 to 2019.”
