Marijuana-related Car Accidents in Washington

The AAA Foundation for Traffic Safety recently finalized a study on the Prevalence of Marijuana Use Among Drivers in Fatal Crashes: Washington, 2010-2014. They found that from 2010 through 2013, the estimated number and proportion of drivers involved in fatal crashes who had a detectable concentration of THC in their blood doubled from 2013 to 2014 after Initiative 502 took effect. From their analysis it appears that after Initiative 502 took effect there was a relatively stable amount of deaths where people had detectable concentration of TCH in their system. About nine months after the initiative was passed, there was a significant increase.

Quarterly average proportion of drivers involved in fatal crashes who were positive for THC and modeled seasonally-adjusted linear trend before and after Washington Initiative 502 took effect on 6 December 2012 legalizing recreational use of marijuana for adults aged 21 years and older, Washington, 2010 – 2014. Taken from report.

Quarterly average proportion of drivers involved in fatal crashes who were positive for THC and modeled seasonally-adjusted linear trend before and after Washington Initiative 502 took effect on 6 December 2012 legalizing recreational use of marijuana for adults aged 21 years and older, Washington, 2010 – 2014. Taken from report.

You can read the final report, see the slideshow, or find out quick information in their fact sheet.