Effect of Recreational Marijuana Sales on Police-Reported Crashes in Colorado, Oregon, and Washington

This 24-page report from the Insurance Institute for Highway Safety (IIHS) presents data on the effect of recreational marijuana sales on police-reported crashes in Colorado, Oregon, and Washington states. Each of these states has allowed retail sales of recreational marijuana, Colorado in January 2014, Washington in July 2014, and Oregon in October 2015. The author notes that the current analysis is based on the 2018 Highway Loss Data Institute research, which estimated that the legalization of retail sales was associated with a 6.0% increase in insurance collision claims, as compared with control states. However, this analysis uses police-reported crashes instead of insurance claims. The author reviewed crash rates between January 2012 and December 2016 for the three states, using neighboring states as controls. Data analysis showed that the legalization of retail sales in these three states was associated with a 5.2% higher rate of police-reported crashes, compared to neighboring states that did not have legal retail sales of marijuana. The report includes appendices presenting the specifics of the regression analyses used to compare crash rates.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 24p

Subject/Index Terms

Filing Info

  • Accession Number: 01684924
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 19 2018 12:29PM