Per Se Limits for Marijuana Impairment

This project will produce a short white paper that will summarize the current research on the connection between delta-9-tetrahydrocannabinol (THC) use, driving performance, and crash risk; basic pharmacology; the history of Driving Under the Influence (DUI) and Driving Under the Influence of Drugs (DUID) laws; law enforcement training for detecting drug impairment; and data availability. An additional topic is the potential consequences (positive, negative and unintended) of adopting or not adopting per se limits that set quantitative thresholds for concentration of THC for determining an impairment offense. The first objective of this project is to perform the search and retrieval portions of a literature review that will support the development a white paper that will help guide policy discussions related to adoption of a per se limit for THC. The second objective is to develop an annotated bibliography comprised of all the documents retrieved during the literature search.

  • Supplemental Notes:
    • This study is being conducted under the National Cooperative Research and Evaluation Program (NCREP), which is administered by the National Highway Traffic Safety Administration (NHTSA) and jointly managed by NHTSA and the Governors Highway Safety Association.


  • English


  • Status: Active
  • Funding: $19,314
  • Contract Numbers:


  • Sponsor Organizations:

    National Highway Traffic Safety Administration

    1200 New Jersey Avenue, SE
    Washington, D.C.  United States  20590

    Governors Highway Safety Association

    444 N. Capitol Street, NW, Suite 722
    Washington, DC  United States  20001

    Office of Behavioral Safety Research

    1200 New Jersey Avenue, SE
    Washington, District of Columbia  United States  20590
  • Project Managers:

    Smither, Dereece

  • Performing Organizations:

    Volpe National Transportation Systems Center

    Cambridge, MA  United States  02142
  • Start Date: 20160801
  • Expected Completion Date: 20231231
  • Actual Completion Date: 0
  • USDOT Program: Behavioral Safety Research
  • Subprogram: Drug Impaired Driving
  • Subprogram: NCREP

Subject/Index Terms

Filing Info

  • Accession Number: 01641192
  • Record Type: Research project
  • Source Agency: National Highway Traffic Safety Administration
  • Contract Numbers: DTNH2215V00014
  • Files: RIP, USDOT
  • Created Date: Jul 18 2017 5:53PM