Recently I was asked if the legalization of marijuana was having an impact on impaired driving. I knew anecdotally, from conversations I’ve had with the law enforcement community, that officers were encountering more drivers impaired by marijuana, and I knew that over the last few years we’ve had a trend of less alcohol impaired drivers and more drug impaired drivers, but I hadn’t taken a close look at the data.
I spent some time reviewing the Washington Traffic Safety Commission’s Fatality Analysis Reporting System (FARS) data, and I put together this chart:
Looking at the marijuana column, we see a sharp increase in 2014, but it’s hard to know for sure what kind of impact the legalization of marijuana has had, because it wasn’t available for retail purchase until July of 2014, which only gives us a half-year of data. There’s a definite spike in 2014, but I don’t know if that’s an anomaly or a trend. Once the 2015 data is available it may help to answer that question.
There are some people that will argue that driving high isn’t as big a deal as driving drunk, because marijuana doesn’t affect driving like alcohol does. I’m not interested in getting into a debate, but the data indicate that marijuana is a significant factor in fatal crashes. Of the 462 Washington fatalities in 2014, 99 had marijuana impairment as a factor. That works out to over 21%. A SAMSA study estimates that about 10% of Washingtonians use marijuana. That’s not the estimate of people who use and then drive; it’s just users. I think the data makes the point, but just to drive it home, drivers in a demographic that makes up less than 10% of the population are responsible for over 20% of traffic fatalities. A recent report by the Washington Traffic Safety Commission looks in-depth at impaired drivers and the various types of substances causing impairment; those who mix alcohol and marijuana are by far more dangerous than those who use one or the other.
The other trend that’s captured in the chart is the decrease in alcohol DUI fatalities and the coinciding increase in drug DUI fatalities. I can’t find any studies that indicate that alcohol consumption is decreasing; maybe we’ve become better as a society at not driving drunk. However, the total number of DUI fatalities remains virtually unchanged due to drugged driving. What you don’t see in this chart is that impaired drivers are responsible for half of all traffic fatalities in Washington. We’ve made progress compared to ten and twenty years ago, but we still have a way to go to to solve this issue. Got any ideas? I’m open to suggestions.