Traffic Safety Impacts of Marijuana Legalization

As of October 2018, nine states have legalized recreational marijuana, and similar legislation has been proposed in at least 20 others. As states consider changing their laws, it is important to take into account the traffic safety ramifications legalized marijuana may have. To help states understand these impacts, GHSA has compiled the most pertinent research into Traffic Safety Impacts of Marijuana Legalization, a succinct, four-page guide to the issue.

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By analyzing research from Colorado and Washington, the document finds that after these states legalized recreational marijuana:

• Marijuana use increased according to data from Colorado and Washington.
• THC presence increased in drivers on the road and in arrested and crash-involved drivers according to data from Washington. THC-positive drivers may not necessarily be impaired.
• There are no firm conclusions on whether crash rates changed in either state.
• Fatal crashes involving marijuana increased in both Colorado and Washington.
• Surveys in Colorado and Washington show that many regular marijuana users believe that marijuana doesn’t affect their driving. Most regular users will drive “high” frequently.

The guide was authored by nationally-recognized subject matter expert and former National Highway Traffic Safety Administration (NHTSA) official Dr. Jim Hedlund.