Marijuana, Other Drugs, and Alcohol Use by Drivers in Washington State: Appendices

Details

• Creators:
  Ramirez, Anthony ; Berning, Amy ; Carr, Katherine ; Scherer, Michael ; Lacey, John H. ; Kelley-Baker, Tara ; Fisher, Deborah A.
• Corporate Creators:
  Pacific Institute for Research and Evaluation
• Corporate Contributors:
  United States. Department of Transportation. National Highway Traffic Safety Administration. Office of Behavioral Safety Research ; Insurance Institute for Highway Safety
• Subject/TRT Terms:
  • Marijuana
  • Alcohol use
  • Impaired drivers
  • Drug use
  • Testing
  • Data collection
  • Before and after studies
  • Night
  • Alcohol and driving
  • drugs and driving
  More +
• Publication/ Report Number:
  DOT HS 812 299
• Series:
  Roadside and Crash Risk Studies
• DOI:
  https://doi.org/10.21949/1525829
• Resource Type:
  Tech Report
• Geographical Coverage:
  Washington
• Corporate Publisher:
  United States. National Highway Traffic Safety Administration. Office of Behavioral Safety Research
• Abstract:
  In Washington State legal sales of marijuana began July 8, 2014. A voluntary, anonymous roadside study was conducted to assess the prevalence of drivers testing positive for alcohol and other drugs, including marijuana, on Washington’s roads. Data was collected in three waves, before implementation of legal sales, about 6 months after implementation, and 1 year after implementation. Of the almost 2,400 participants who provided an oral fluid or blood sample, 14.6 percent of drivers, 19.4 percent of drivers, and 21.4 percent of drivers were THC-positive in Waves 1, 2, and 3, respectively. There were no statistically significant differences between waves. There was a statistically significant increase in daytime prevalence of THCpositive drivers between Wave 1 (7.8%) and Wave 2 (18.4%), and also between Wave 1 and Wave 3 (18.9%). There was an increase in the percentage of THC-positive nighttime drivers with each successive wave, but these increases were not statistically significant. Synthetic marijuana was found in only 2 of the participants.
• Format:
  PDF
• Funding:
  DTNH22-11-D-00226-0004
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/2010/dot_2010_DS1.pdf
• File Type:
  [PDF - 1.53 MB]
• Collection(s):
  NHTSA - Behavioral Safety Research
• Main Document Checksum:
  urn:sha-512:d2fcf656461cf02a602e819a7a2a9ac2b649a5a7f8be3783abc3c22db75ae036a2c7164fbb5b91652b4bd500b133ba7eca772f7d5de75016fa10596d9cbc228e