Key Information for DUIC Policy

There is growing concern about driving under the influence of cannabis (DUIC), especially as more states consider changing laws to legalize cannabis. A key question regarding the legalization of cannabis for recreational or medical purposes is its potential impact on public health issues such as traffic safety. To address the needs of traffic safety practitioners and policymakers, this synthesis report seeks to summarize key information about the role of cannabis in traffic safety in order to inform policy regarding cannabis legalization and traffic safety. Main conclusions include: (1) Cannabis is a plant-based drug that is typically smoked or ingested. (2) Cannabis is the most commonly used illicit drug in the U.S. (3) The primary psychoactive compound of cannabis is delta-9-tetrahydrocannabinol (THC). (4) THC is transported by the circulatory system to the brain where it alters neural activity and brain functions. (5) Changes in neural activity and brain functions can impair core cognitive functions such as attention. (6) Cognitive impairment results in impaired driving behaviors. (7) Impaired driving behaviors increase driver responsibility for motor vehicle crashes. (8) THC-positive drivers are twice as likely to be killed in a motor vehicle crash. (9) The fatal crash risk is much higher when THC is combined with alcohol. Currently, there is some evidence that the legalization of recreational cannabis increases crashes. However, because it has been only recently that relatively few states have adopted this legislation, the amount of evidence is insufficient for a definitive conclusion. Thus, there is a need for more research to examine the effect of cannabis legalization on traffic safety. Such research will require longer post-legalization periods and more states that have enacted these legislative changes.

• Record URL:
  • https://www.mdt.mt.gov/research/projects/trafficsafety-duic.shtml
• 
• Corporate Authors:

  Montana State University, Bozeman

  Center for Health and Safety Culture
  Bozeman, MT  United States 

  Montana Department of Transportation

  2701 Prospect Avenue
  P.O. Box 201001
  Helena, MT  United States  59620-1001

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Ward, Nicholas
  • 0000-0002-2792-8082
  • Otto, Jay
  • 0000-0003-0975-0249
  • Finley, Kari
  • 0000-0002-0887-4939
• Publication Date: 2019-6

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Figures; References; Tables;
• Pagination: 44p

Subject/Index Terms

• TRT Terms: Crash rates; Drugged drivers; Drugs; Literature reviews; Marijuana; Policy, legislation and regulation; Traffic safety
• Geographic Terms: United States
• Subject Areas: Highways; Law; Policy; Safety and Human Factors;

Filing Info

• Accession Number: 01715197
• Record Type: Publication
• Report/Paper Numbers: FHWA/MT-19-005/8882-309-10
• Files: TRIS, ATRI, USDOT, STATEDOT
• Created Date: Aug 29 2019 9:32AM