NTL Record

Title Marijuana, Other Drugs, and Alcohol Use by Drivers in Washington State: Appendices
Record ID 61137
Personal Name
Creator
Ramirez, Anthony; Berning, Amy; Carr, Katherine; Scherer, Michael; Lacey, John H.; Kelley-Baker, Tara; Fisher, Deborah A.
Corporate Creator Pacific Institute for Research and Evaluation
Corporate
Contributor
United States. Department of Transportation. National Highway Traffic Safety Administration. Office of Behavioral Safety Research; Insurance Institute for Highway Safety
Publisher United States. National Highway Traffic Safety Administration. Office of Behavioral Safety Research
Publication Date 20160700
Language English
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.
Rosap ID dot:2010
Rosap URL https://rosap.ntl.bts.gov/view/dot/2010
TRT Terms Marijuana; Alcohol use; Impaired drivers; Drug use; Testing; Data collection; Before and after studies; Night
General Subjects Alcohol and driving; drugs and driving; roadside survey; impaired driving; drugged driving; alcohol-involved driving; drug-involved driving; legalization; marijuana; Washington State; cannabis; THC
Geographical
Coverage
Washington
Contract Number DTNH22-11-D-00226-0004
Report Number DOT HS 812 299
Availability NHTSA - Behavioral Safety Research
Resource type Tech Report
URL https://ntlrepository.blob.core.windows.net/lib/61000/61100/61137/812299a-washingtonstatedrugstudy-appendices.pdf
Format PDF
Database NTL Digital Repository