Cannabis and Cars
Did traffic fatalities increase or decrease after cannabis legalization?
Is cannabis-impaired driving a public health and safety concern? Well, the number of tickets for cannabis-impaired driving went up in Washington State after legalization, as did the proportion of drivers in fatal car crashes in Colorado who tested positive for marijuana use. But, in both cases, this “may simply reflect a general increase in marijuana use” overall. It doesn’t mean that cannabis is causing the crashes, as I discuss in my video The Effects of Marijuana on Car Accidents.
There is a lot of evidence correlating marijuana use with car accidents, but who uses marijuana Mostly young people and males. And guess who has a higher crash risk regardless of what they smoke? Young people and males. However, even taking that into account, it does seem that “roughly 20–30% of traffic crashes involving cannabis use occur because of the cannabis use.” But, to put that in perspective, that number is more like 85 percent when it comes to alcohol.
Aren’t cannabis crashes low-velocity fender-benders from an impaired driver going like five miles an hour? “After a systematic review of the literature,” a compilation of studies “examining acute cannabis consumption and motor vehicle collisions…found a near doubling of the risk of a driver being involved in a motor vehicle collision resulting in serious injury or death.” So, that’s pretty serious, but alcohol is even worse. Cannabis may double or triple the risk of car crashes, but alcohol may multiply the risk 6- to 15-fold. The combination may be even worse—25 times the odds of a fatal car crash involvement when testing positive for both cannabis and alcohol.
