Marijuana Users Are Way Less Likely To Get In An Accident Than Alcohol Users

The National Highway Traffic Safety Administration released a study comparing the relative driving safety risk of alcohol use and marijuana use, respectively, and it has a few important takeaways, as explained in depth by the Washington Post. Basically, it boils down to “marijuana users are less likely to be in accidents than alcohol users,” but it’s a little more complicated than that.

First of all, it’s important to remember that THC from marijuana use is detectable in blood for days or even weeks after the psychoactive effects of marijuana wear off. So when you study accident reports in relation to THC levels, you could be looking at data about people who, for all intents and purposes, were sober when they were driving.

That being said, when the data was adjusted for age, gender, race, and alcohol use, marijuana users were no more likely to get into a crash than someone who was stone cold sober before driving. Alcohol users were almost six times as likely to get in an accident, on the other hand. It’s tempting to speculate that the psychoactive effects of marijuana are more conducive to safe driving (paranoia, etc.), but again, we might be looking at data about people who were completely sober and just had THC still in their blood while they were driving. There are only a handful of studies about how drivers perform when they’re under the psychoactive effects of marijuana, but research suggests that in those conditions, drivers are, yes, more likely to drive slowly, but also more likely to weave through lanes, and have a difficult time with tasks that require split attention and quick reaction.

However, the issue is further complicated by the fact that level of THC concentration in the blood does not correlate with level of impairment — so setting legal minimums of THC concentration is pointless and serve to punish people who, for instance, might have acquired their marijuana legally (in states where it’s been legalized), used it legally, and were sober when they drove, but who still had THC in their blood. We need better tools to identify drivers who are operating their cars while they’re experiencing the psychoactive effects of marijuana, but as Christopher Ingraham at the Post pointed out, they’re hard to develop while the federal government still classifies marijuana as being as dangerous and illegal as heroin.

[Washington Post]

[National Institutes of Health]

[Image via Shutterstock]

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