Car crashes rose as much as 6 percent in states where the recreational use of marijuana has been legalized, two studies found. Research from the Insurance Institute for Highway Safety and the Highway Loss Data Institute said the frequency of collision claims filed to insurers were higher in four states where marijuana is legal: Colorado, Nevada, Oregon and Washington. The studies were presented Thursday at the “Combating Alcohol- and Drug-Impaired Driving” summit, USA Today reports. The Highway Loss Data Institute study focused on collision claims between 2012 and October 2017, comparing them against four states where marijuana remains illegal: Idaho, Montana, Utah and Wyoming.
A separate study by the Insurance Institute for Highway Safety focused on police-reported crashes before and after retail marijuana was allowed. It found Colorado, Oregon and Washington saw a 5.2 percent increase in the rate of crashes per million vehicle registrations, compared with neighboring states. “States exploring legalizing marijuana should consider this effect on highway safety,” said David Harkey, president of the Insurance Institute for Highway Safety and Highway Loss Data Institute. Nine states — Alaska, California, Colorado, Maine, Massachusetts, Nevada, Oregon, Vermont and Washington — and the District of Columbia have legalized marijuana use. Michigan and North Dakota will vote next month on whether to allow marijuana for recreational use. The institute acknowledges determining whether someone is impaired by marijuana in the case of a car accident is difficult. See also The Crime Report’s “Pre-Election Primer: Justice and the Midterms.”