OLYMPIA, Wash.— When recreational marijuana became legal in the state, some feared there would be more people driving high and causing deadly crashes. A new report from the Washington Traffic Safety Commission says some of those fears may have been justified.
This is the first time the state has looked at how pot has impacted traffic safety in this detail. It looks at how many marijuana-positive drivers were involved in deadly crashes.
Staci Hoff, research director for the Washington Traffic Safety Commission, says for the first time the state has data that differentiates drivers who had residual marijuana in their system versus active levels of THC.
The trend they’ve seen is the level of residual marijuana, called carboxy, may have remained stable over the years since 2010, but THC, the recent-use indicator, saw an increase.
“Which is saying that people aren't waiting after using, they're using and then driving,” said Hoff.
Another important finding? Drivers combining marijuana and alcohol showed increased risk.
“They had the lowest seatbelt use rate, they had higher rates of speeding than drivers who are under the influence of alcohol,” said Hoff.
Hoff says the data doesn`t say for sure if drivers under the influence of marijuana caused the deadly crashes, but the numbers show since 2010, 60 percent of drivers tested positive for alcohol, marijuana or drugs.
“It's something that we have to continue to monitor,” said Hoff. “I know the research is really out on whether or not marijuana is a safety concern in traffic safety, but two recent meta studies, which is the best meta studies I've been able to find to date, independently concluded that marijuana increases crash risk-- it doubles it.”
The report also found more drivers tested positive for THC while the number of drivers under the influence of alcohol went down.