A report from the Washington Traffic Safety Commission finds that marijuana is growing as a factor in fatal vehicle crashes.
The number of drivers involved in fatal crashes who tested positive for the drug increased 48 percent from 2013 to 2014, according to the Commission.
"We have seen marijuana involvement in fatal crashes remain steady over the years, and then it just spiked in 2014," said Dr. Staci Hoff, WTSC Data and Research Director.
Washington residents voted to legalize recreational marijuana in 2012, and the first retail outlets opened in 2014.
The number of drivers testing positive for active THC, the impairing ingredient in marijuana, increased from 65 percent (38 of 60 drivers) in 2013 to 85 percent in 2014 (75 of 89 drivers).
Males aged 21-25 saw the most significant increase in age group, from 6 percent in 2013 to 19 percent in 2014.
It's against Washington law for drivers and passengers to use marijuana while driving. Pot can't be carried in a vehicle unless in its original sealed package, or kept in the trunk.
From the report:
"Just testing positive for marijuana doesn't necessarily indicate if a driver was actually affected by the drug at the time of the crash since marijuana can be detected in a person's blood for days (possibly weeks) after a person uses the drug. This new data is able to distinguish between drivers who test positive for THC, the impairing substance in marijuana and those who have residual marijuana in their system from prior use which may have occurred days ago."