Addictions, Drug & Alcohol Institute

Impacts of Cannabis & Cannabis Legalization on Impaired Driving in WA State

In conjunction with the Harborview Injury Prevention & Research Center, this project examined the relationship between changes in Washington State cannabis laws and policies and the incidence of cannabis-impaired driving, using linked toxicological, criminal justice, and crash databases. Also examined was the relationship between the presence and level of cannabis metabolites in driver blood samples and the severity of driving offense, rates, and police-reported crash severity.


Caleb Banta-Green, PhD, MPH, MSW PI (UW ADAI)
Ali Rowhani-Rahbar, MD, MPH, PhD Co-PI (UW School of Public Health)
Beth E. Ebel, MD, MSc, MPH Co-Investigator (UW School of Public Health)

Fund Information

AAA Foundation
Start: July 2014
End: September 2015
Status: completed

Project Results

Cannabis Use among Drivers Suspected of Driving Under the Influence or Involved in Collisions: Analysis of Washington State Patrol Data. C Banta-Green, A Rowhani-Rahbar, B Ebel, LM Andris, and Q Qui. Report for the AAA Foundation, 6/2016. Report & related resources