The Insurance Institute for Highway Safety just released information on a study stating that legalizing recreational marijuana could lead to an increase in car crashes. This is based on research looking at crash statistics in Colorado, Nevada, Oregon and Washington, and comparing it to data from neighboring states. The findings: crash frequency from the aforementioned states where pot is legal is up 6 percent compared to neighboring states where recreational use of pot remains outlawed. Analysts controlled for a number of factors, including: “differences in the rated driver population, insured vehicle fleet, the mix of urban versus rural exposure, unemployment, weather and seasonality.”
A separate IIHS study examined 2012–16 police-reported crashes before and after retail sales began in Colorado, Oregon and Washington. IIHS estimates that the three states combined saw a 5.2 percent increase in the rate of crashes per million vehicle registrations, compared with neighboring states that didn’t legalize marijuana sales.
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. 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.
https://www.iihs.org/iihs/news/desktopnews/crashes-rise-in-first-states-to-begin-legalized-retail-sales-of-recreational-marijuana