Researchers from Columbia University’s Mailman School of Public Health released information this week that could negate one of the most common arguments against cannabis legalization: that easier access to marijuana will mean an increase in stoned driving and therefore more traffic fatalities. In fact, the opposite appears to be the case, at least in regards to medical marijuana legislation.
The study’s authors announced their results this week, which found that — in states where medical cannabis has been made available — traffic fatalities have seen a dramatic 11 percent reduction, the Washington Post reports. This correlation was also present in regions with close access to medical marijuana dispensaries.
Physician and associate professor Dr. Silvia Martins, the study’s senior author, posited that these reductions could be the result of people choosing to use cannabis over alcohol, which would lead to fewer drunken drivers.
The study showed that traffic fatalities had primarily fallen among drivers aged 15-45, but there was not dramatic change among drivers who were older than 45.
It also should be noted that not every state with medical cannabis laws saw only lowered rates of traffic fatalities — California and New Mexico, for example, at first saw reductions of 16 and 17.5 percent, but those rates gradually increased over time.
The results were first published online in the American Journal of Public Health. The study considered 23 states and the District of Columbia, and researchers analyzed data on traffic fatalities from the National Highway Traffic Safety Administration taken from 1985 to 2014. During the time the study was conducted, nine additional states established medical marijuana programs. Researchers adjusted their numbers to account for many different factors, including when a state had graduated driver licensing laws, speed limit maximums, specific seat belt and cellphone use laws, and more.