Higher Risk: Study Claims States That Legalized Marijuana Have More Traffic Accidents

Matt Posky
by Matt Posky
higher risk study claims states that legalized marijuana have more traffic accidents

The Insurance Institute for Highway Safety and the Highway Loss Data Institute announced Thursday that auto crashes in states with legalized recreational marijuana have increased 6 percent. Both groups will be on hand at the Combating Alcohol-and Drug-Impaired Driving summit at IIHS’ Vehicle Research Center in Ruckersville, Virginia to present two studies on the issue. Perfect timing, considering Canada just became the second country to legalize the substance and support for decriminalization continues to grow in the United States.

Of course, things are rarely so simple. While the IIHS and HLDI remain confident in their research, the National Highway Traffic Safety Administration claimed marijuana use was unlikely to contribute to traffic mishaps in any meaningful way back in 2015. And that’s just for starters. There is so much conflicting information on this issue, it’ll make your head spin harder than the most savage bong rip of your life, bro.

While there’s no reason to doubt the data from the IIHS, it could also be claimed that it’s in the organization’s best interests to find new ways to elevate insurance rates while simultaneously conducting meaningful crash test research. In this instance, analysts estimated that the frequency of collision claims per year rose a combined 6 percent following the start of legal sale of recreational marijuana in Colorado, Nevada, Oregon, and Washington versus the control states of Idaho, Montana, Utah and Wyoming. That data came via collision loss information collected between January 2012, when recreational sales began for Colorado and Washington, and October 2017.

A separate IIHS study examined police-reported crashes between 2012 and 2016, before and after retail sales began in Colorado, Oregon and Washington. The IIHS estimated the three states combined saw a 5.2 percent increase in the rate of crashes per million vehicle registrations, compared with neighboring states that did not legalize marijuana sales. However, it can’t accurately attribute this to marijuana, just that there is a correlation of some kind — which is important to remember while considering the data.

According to the National Safety Council, countrywide crash rates rose by 6 percent in 2016 and 7 percent in 2015. Framed this way, the pot-smoking states seems to be roughly on par with the national average. See how slippery statistics can be?

Let’s keep playing devil’s advocate and swap sides. Fatalities on U.S. roads fell slightly in 2017 after two years of sizable increases. But on-road deaths in Colorado continued to climb. In fact, 2017 was the worst year for the state since 2004… when it had a significantly smaller population and marijuana wasn’t legal. Swapped again!

We could do this all day. The issue might even come down to some of these state’s incredibly swift population growth. Still, IIHS analysts say they controlled for “differences in the rated driver population, insured vehicle fleet, the mix of urban vs. rural exposure, unemployment, weather and seasonality.” Maybe there is something to this, if they truly managed to nullify any margin of error.

Previous research efforts have strongly hinted that driving under the influence of marijuana is less debilitating than alcohol — not just because THC has less of an affect on fine motor skills, but also because those using it are statically less likely to feel confident in engaging in complex tasks or risk-taking behaviors. Typically, the inverse of this is true when it comes to booze. However, the consumption alcohol is more easily measured and the outward signs of impairment are usually more visible, while the amount of marijuana present in a person’s body doesn’t consistently relate to impairment.

Those earlier studies also indicated that regular pot smokers are less likely to have issues. Despite the demonstrable neurophysiologic impairments associated with THC, studies involving experienced smokers driving on an outdoor course have shown almost no functional impairment under the influence of marijuana — except when combined with alcohol. We covered those studies last year, some of which are highly intriguing, when the IIHS and HLDI claimed that collision frequencies in Colorado, Oregon and Washington were roughly 3 percent higher than what would have been expected without legalization.

This year sees the agencies taking a more serious run at the burning bush. “The new IIHS-HLDI research on marijuana and crashes indicates that legalizing marijuana for all uses is having a negative impact on the safety of our roads,” said IIHS-HLDI President David Harkey. “States exploring legalizing marijuana should consider this effect on highway safety.”

“Despite the difficulty of isolating the specific effects of marijuana impairment on crash risk, the evidence is growing that legalizing its use increases crashes.”

It should be said that driving under the influence of either alcohol or marijuana is totally against the law and not something we condone. Neither substance should be in your system when you take the wheel, regardless of their legal status. But the Insurance Institute for Highway Safety seems to be taking things a step further by subtly suggesting that states might want to think twice about decriminalizing recreational pot. Following that logic, it seems they’d probably want to push for the prohibition of alcohol as well.

Join the conversation
3 of 21 comments
  • Kamiller42 Kamiller42 on Oct 23, 2018

    Increasing accessibility, and therefore usage, to a psychotropic drug increases accidents? Anyone really surprised?

  • Zipper69 Zipper69 on Apr 23, 2020

    Real men get plastered - right?

    • -Nate -Nate on Apr 23, 2020

      Getting plastered is fine, just DO NOT DRIVE NOR RIDE when you are . Pretty simple unless you're a mouth breather . -Nate

  • Wjtinfwb I'll certainly admit to a bit of nostalgia that drives my appreciation for these 70's yachts, but there's more to it than that. It was an era that the Big 3 ruled the luxury market with the German's and British nothing but a beer fart in the marketplace. That changed drastically as the early '80s crept in but in 1977, a Mark V or Seville was where it was at. No rose colored glasses, they were not great cars, what they were was a great living room that you could ride to the office in. I grew up on a diet of Cadillac's, Lincoln and one big Chrysler before dad made the move to a 280SE in about '77. Impeccably built and very road worthy, dad initially didn't like the firm seats, clunky automatic transmission and very weak A/C. The exorbitant maintenance costs didn't help. But he enjoyed the driving characteristics enough to get another Benz, then a 733i, an Audi 5000S and a Jag XJ6. Compare these to today's Cadillac's (non- V) and Lincoln's that with the exception of the Escalade and Navigator, are boring and probably even more pedestrian than the Eldorado, Seville and Mark's were.
  • FreedMike I was lucky enough to grow up in a household with the two best German luxury sedans of the time - a manual '81 733i, and a '75 Mercedes 450SE. The BMW was a joy on back roads, and the Benz was a superb highway car. Good times. And both were dramatically better than the junkheap American luxury cars Dad had before.
  • Wjtinfwb A Celebrity Diesel... that is a unicorn. Those early A-bodies were much maligned and I'm sure the diesel didn't help that, but they developed into very decent and reliable transportation. Hopefully this oil-burner Chevy can do the same, it's worth keeping.
  • Wjtinfwb After S-classes crested the 40k mark in the early '80s, my dad moved from M-B to a BMW 733i Automatic. Anthracite gray over red leather, it was a spectacular driving car and insanely comfortable and reassuring on long interstate hauls. My mom, not really a car person, used the BMW to shuttle her elderly Mom back home to Pennsylvania from Miami. Mom and grandma both gushed with praise for the big BMW, stating she could have driven straight through the car was so comfortable and confidence inspiring. A truly great car that improved through the E38 generation, at which point the drugs apparently took hold of BMW styling and engineering and they went completely off the rails. The newest 7 series is a 100k abomination.
  • Vatchy If you want to talk about global warming, you might start here: https://en.wikipedia.org/wiki/Darvaza_gas_crater