Car Crashes Increased In States Legalizing Recreational Marijuana

From MarketWatch, "Car crashes rise in states where marijuana is legal relative to states where it isn't--IIHS-HDLI" by Tomi Kilgore:

Car crashes are up by as much as 6% in the four states in which recreational marijuana is legal, compared with neighboring states in which it is still illegal, according to report published Thursday by the Insurance Institute for Highway Safety (IIHS) and the Highway Loss Data Institute (HLDI).***The report said analysts controlled for differences in the rated driver population, insured vehicle fleet, the mix of urban versus reual exposure, unemployment, weather and seasonality. "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."