New research suggests after states legalized marijuana for recreational use, a significant increase was seen in the number of annual car accidents. 

In a study published by the Insurance Institute for Highway Safety (IIHS) and Highway Loss Data Institute (HLDI), researchers indicate that the four states with legal recreational marijuana have seen approximately a six percent increase in automobile crashes since retail sales commenced.

Researchers compared insurance claims for automobile crashes in Washington, Colorado, Nevada and Oregon, where marijuana use is legal, comparing data to Idaho, Montana, Utah, and Wyoming, where marijuana use is still illegal.

The results indicated states with legalized marijuana had an increase in car accident claims when compared to their neighboring state, and each state also saw crash increases when compared to the year prior to legalizing marijuana.

“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,” IIHS-HLDI President David Harkey said in a press release. “States exploring legalizing marijuana should consider this effect on highway safety.”

IIHS warns that drivers are largely unaware of the risks associated with using marijuana and driving, and recent studies found that those driving while under the influence are more likely to have children in the car or drive during busier daytime hours than alcohol-impaired drivers.

The study was presented last week at the Combating Alcohol and Drug-impaired Driving summit, hosted by the IIHS at the Vehicle Research Center. The summit included a variety of highway safety officials and law enforcement experts to discuss the prevalence and associated risk of alcohol and drugs on the roadways, and methods to combat these issues.

One issue posing a significant challenge to law enforcement is detecting drivers under the influence of marijuana due to the inability to detect THC levels, which are the psychoactive component of cannabis that affects one’s driving ability. Unlike alcohol, there is no quick roadside way to determine a level of THC, nor is there a scientific basis for what level of THC would render an individual too impaired to drive.

The National Highway Traffic Safety Administration (NHTSA) recently launched a new initiative to combat drugged driving in January, indicating that the steps are being taken in response to the growing opioid epidemic in the U.S., and the trend of states legalizing the use of marijuana.

Despite efforts to combat drugged driving, voter approval for decriminalizing marijuana has gained a lot of momentum across the states, with more legislators supporting marijuana for recreational use.

Legalization of recreational use is currently pending in several states including New Hampshire, New Jersey, New York and Pennsylvania. In November, Michigan and North Dakota will hold referendums on marijuana, and Missouri and Utah voters will decide whether to expand medical marijuana laws in their states.

Tags: Auto Accident, Drugged Driving, Marijuana