The Washington Times

Marijuana_420_weed_mary_jane_drugs_3000x2000Roughly 10 percent of Washington state drivers involved in fatal car crashes between 2010 and 2014 tested positive for recent marijuana use, with the percentage of drivers who had used pot within hours of a crash doubling between 2013 and 2014, according to a new study by the AAA Foundation for Traffic Safety.

Although the uptick in fatal crashes comes after Washington citizens voted in 2012 to legalize marijuana — and as other states are expected to consider similar measures — a second AAA study discourages lawmakers from adopting “arbitrary legal limits” on marijuana use because of a lack of adequate methods to determine impairment by the drug.

AAA officials said the studies about marijuana and driving, released Tuesday, are meant to encourage more comprehensive enforcement measures to improve road safety.

Authorities in Washington recorded 436 fatal crashes in 2013, and determined that drivers involved in 40 crashes tested positive for THC, the active chemical in marijuana, according to the study. In 2014 they found that of 462 fatal crashes, 85 drivers tested positive for THC.
The fatal crash study does not determine whether drivers were impaired, and it notes that there was no sign of an increase in fatal crashes among those with marijuana in their systems until a full 39 weeks after marijuana possession was legalized in the state.