California legalized recreational marijuana use and retail sales of cannabis five years ago. Proponents in Costa Mesa and across the state hoped and believed that legalization would not make our streets, roads and highways more dangerous.
A consequence of legalization
Unfortunately, there is emerging evidence that motor vehicle crash rates rise when states legalize recreational marijuana use.
Following legalization, vehicle wreck rates rose in California, Oregon, Washington, Nevada and Colorado, according to a new study by the Insurance Institute for Highway Safety (IIHS).
“Our latest research makes it clear that legalizing marijuana for recreational use does increase overall crash rates,” said IIHS President David Harkey.
The IIHS study shows there was a 6 percent increase in the auto accident injury crash rate following legalization in the group of states studied. There was also an average 4 percent increase in fatal wreck rates compared with neighboring states where recreational marijuana use remained illegal.
The results are consistent with 2018 IIHS research of police-reported crashes that found that following the legalization of retail marijuana sales in Colorado, Washington and Oregon, the crash rate was 5 percent higher than in nearby states that had not legalized cannabis.
Nineteen states have legalized recreational marijuana use for adults. Because legalization has generated substantial tax revenue in those states, more states are considering similar legislation. In addition, recent polls indicate slightly more than two-thirds of U.S. adults favor legalization.
Marijuana consumption: Up
Consumption also appears to be on the rise, with self-reports of recent weed use doubling from 6 percent in 2008 to 12 percent in 2019.
The upward shift in consumption worries road safety advocates. Driving simulation studies show that people high on marijuana react slower, pay less attention, have more difficulty maintaining lane position and make more mistakes than they do when sober.
Combination substance use up, too?
One theory gaining traction is that legalization of marijuana leads to an increase in drivers who combine alcohol and weed use – a theory bolstered by a separate recent study by the AAA Foundation for Traffic Safety. It found that drivers who said they use both alcohol and weed are more likely than those who say they consumed alcohol only to have both driven impaired and driven dangerously (speeding on residential streets, making aggressive maneuvers, etc.).
Clearly, the data shows that legalization of recreational marijuana use pushes auto crash rates higher – an element of legalization that states should consider before following California’s example.