Impact of the Legalization and Decriminalization of Marijuana on the DWI System: Highlights From the Expert Panel Meeting

In Moving Ahead for Progress in the 21st Century (MAP-21) Act, Congress directed NHTSA to establish a cooperative program—the National Cooperative Research and Evaluation Program (NCREP)—to conduct research and evaluations of State highway safety countermeasures. NCREP was continued in the Fixing America’s Surface Transportation Act. This program is administered by NHTSA, and managed jointly by NHTSA and GHSA. Each year, the States (through GHSA) identify potential highway safety research or evaluation topics they believe are important for informing State policy, planning, and programmatic activities. One such topic identified by GHSA, the legalization and decriminalization of marijuana, forms the basis for this project. States need information about the impacts of laws that legalize or decriminalize the use of marijuana, including its impact on driving safety and the State’s driving while impaired (DWI) system. NHTSA and GHSA convened one-and-a-half day expert panel of professionals involved in and impacted by the enactment of recreational and/or medical marijuana laws. Participants represented States that had enacted such laws (e.g., Washington, Colorado, Oregon, California) and fields of practice that are engaged in the DWI system, including law enforcement, prosecutors, judges, probation, toxicologists, and highway safety officials. The objectives of the expert panel included (a) identifying changes to the DWI system following enactment of laws legalizing and/or decriminalizing marijuana for medical and/or recreational purposes; (b) identifying lessons learned by these States; and (c) identifying measures that should be used to evaluate the effects of enacting recreational and/or medical marijuana laws, and their impact on traffic safety and the DWI system, using both quantitative and qualitative methods. Convening the expert panel was Phase I of a two-phase project to determine the impacts of laws legalizing or decriminalizing marijuana. Phase II will be a project to collect the data based on the recommendations of the panelists. Details about the meeting logistics, the panelists, and their discussions and recommendations are summarized in this report.


  • English

Media Info

  • Media Type: Web
  • Features: Appendices; References; Tables;
  • Pagination: 30p

Subject/Index Terms

Filing Info

  • Accession Number: 01640715
  • Record Type: Publication
  • Report/Paper Numbers: DOT HS 812 430
  • Created Date: Jul 5 2017 2:21PM