Citation

Hamzeie R, Thompson I, Roy S, Savolainen PT. Transp. Res. Rec. 2017; 2660: 78-85.

Copyright

(Copyright © 2017, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

10.3141/2660-11

PMID

unavailable

Abstract

Recently, several states have revisited their laws governing cannabis possession and consumption. Whereas some states have legalized cannabis use at different levels (i.e., legal recreational use, decriminalized possession, or legal medical use), others have zero tolerance. This study used 5 years of data (2010 to 2014) from the Fatality Analysis Reporting System to assess differences across states with various laws for cannabis use. Random parameter logistic regression models were estimated to examine differences in the prevalence of positive cannabis tests across states while controlling for other salient factors, including driver and roadway characteristics. The findings demonstrate that drivers in states with more lenient laws for cannabis possession and consumption were more likely to test positive compared with drivers in states with zero tolerance. In addition, ordinal logistic regression models were estimated to assess the relationships between injury severity, cannabis laws, and other factors associated with crash injury outcomes. The results suggest driver injuries were more severe when the driver tested positive for cannabis. A strong association was also observed between blood alcohol content and cannabis test results. Ultimately, the results provide evidence in support of continuing research to better understand the public health impacts of cannabis use as more states consider changes to the laws governing possession and consumption.

Keywords: Cannabis impaired driving

Language: en