Driving under the influence is illegal no matter where you live, but that isn’t enough to stop people from doing it anyway. Two recent studies confirmed the problem is getting worse as states with legalized recreational marijuana usage are seeing increases in crash rates.
The Insurance Institute for Highway Safety (IIHS) and Highway Loss Data Institute (HLDI) collected data on crashes and found an increase of up to 6 percent in Colorado, Nevada, Oregon, and Washington. These are all states with legalized recreational marijuana usage.
Marijuana was first legalized in Colorado and Washington back in November 2012 with the first retail sales commencing in 2014. Oregon followed close behind making marijuana usage legal in 2014 and retail sales starting in 2015. A year after that, Nevada followed suit.
The HLDI took a look at collision loss data from January 2012 through October 2017 and used Idaho, Montana, Utah, and Wyoming as its control states. They found a combined 6 percent increase in claims in states with legal marijuana usage over that time period.
A separate study conducted by the IIHS looked at police reports of crashes before and after marijuana was legalized from 2012 to 2016. It collected data from Colorado, Oregon, and Washington and found a 5.2 percent increase compared to states without legalized 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,” said IIHS-HLDI President David Harkey. “States exploring legalizing marijuana should consider the effect on highway safety.”
The study looked at the first states to legalize marijuana, but the number of states where it’s now legal to some degree is far greater. Alaska, California, Maine, Massachusetts, Vermont, and the District of Columbia now permit recreational marijuana usage. Medical marijuana is legal in 22 states and another 15 states allow medical marijuana usage for specific medical conditions.
Although it’s illegal to drive under the influence of marijuana, determining a limit for how much is okay in a driver’s system is a challenge. The amount present in a person’s body doesn’t consistently relate to a driver’s impairment.
It also lingers in the body’s system for far longer. The presence of Tetrahydrocannabinol (THC), which is the psychoactive part of cannabis, doesn’t guarantee a driver is impaired. It can also show up days or even weeks after usage in those who are habitual users.
Although it’s difficult to measure how much marijuana causes impairment, these studies do indicate that legalizing this drug leads to increased crashes.