Looking back at the 2014 Oregon State General Election Voter’s Pamphlet, one argument against marijuana legalization was advanced repeatedly. Sheriffs, educators, and anti-weed moralists all agreed that marijuana legalization would unleash stoned hoards of zombie drivers on the road, threatening the safety of Oregonians. And even for many of us who ardently support and end to cannabis prohibition, reasonable questions can be asked about how police can monitor and enforce rules around marijuana and driving. Today, some of those questions may have been answered, as a new study published in the American Journal of Public Health finds that on average, traffic fatalities decrease after medical marijuana is introduced in a state.
The study, which found a similar but reduced effect in the case of the introduction of retail dispensaries, was conducted by researchers at Columbia University’s Mailman School of Public Health. On average, states that introduced medical marijuana saw a rapid 11% decrease in traffic fatalities. States with legal medical marijuana also have traffic fatality rates that are, on average, 26% lower than states that do not allow medical marijuana use.
The study, which was conducted by analyzing traffic fatality data from 1985-2014, does not address the causes of this decrease in fatalities. However, researchers note that the decrease in fatalities in particularly pronounced in the 18-44 year age group. Because this age group has a particularly high instance of driving under the influence of alcohol, follow up research may wish to consider whether the substitution of marijuana for alcohol is responsible for the decrease. This could be the case either because marijuana users are more likely to consume at home than alcohol users are, or because marijuana users are less prone to fatal traffic accidents than alcohol users. The study’s authors also noted that states which do not allow medical or recreational cannabis reported more tolerant attitudes towards driving after consuming alcohol.