Legalized marijuana linked to a sharp rise in car crashes
About 14 percent of drivers under the influence of pot had a child in their vehicle.
by Paul A. Eisenstein / Oct. 18, 2018 / NBCNews
California Highway Patrol officers investigate the scene of a multi-car crash on Interstate 880 in Fremont, Calif. Several people were killed in a multi-car crash that closed several lanes of a major San Francisco Bay highway and officials say the driver suspected of causing it was under the influence of marijuana.
There has been an increase by up to 6 percent in the number of highway crashes in four of the states where the recreational use of marijuana has been legalized, according to a pair of new studies.
“It’s certainly early in the game,” Harkey told NBC News. But, he warned, “We’re seeing a trend in the wrong direction.”
Since the legalization wave began, safety and health experts have been trying to measure the potential influence on highway safety, though the results so far have been inconsistent and, in some cases, contradictory.
But this is the second year in a row where the IIHS found a troubling trend. A year ago, the non-profit group looked at three states, Colorado, Oregon, and Washington. This year, it added Nevada to the list. Harkey said the IIHS also looked at highway crash data in surrounding states to try to control for factors like weather and the economy.
The IIHS also conducted a street-side study of marijuana use and found something Harkey said he saw as particularly concerning. While those under the influence of alcohol tend to either be driving alone or with other adults, about 14 percent of those confirmed to be using pot had a child in their vehicle. That reflects the fact, he added, that marijuana use isn’t confined to evenings and other times when adults are more likely to drink — and abuse — alcohol.
What is unclear is whether that reflects the increasing use of recreational pot or the consumption of medical marijuana to deal with issues like pain or glaucoma, something a patient may time to need.
Police have a particularly difficult challenge because of the way marijuana works in the body. Blood alcohol levels provide a direct correlation showing how much a motorist has had to drink, with those levels dropping rapidly as someone sobers up. But while THC levels spike after smoking weed or eating a consumable, the psychoactive ingredient remains in the body for weeks, long after it has stopped having any impact.
With so many more states set to permit the use of the drug, Harkey said regulators, law enforcement, and medical authorities need to address “the challenge” and come up with better ways of determining when a driver might be operating under the influence of marijuana.