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. 2014 Jul 1:140:137-44.
doi: 10.1016/j.drugalcdep.2014.04.008. Epub 2014 Apr 23.

Trends in fatal motor vehicle crashes before and after marijuana commercialization in Colorado

Stacy Salomonsen-Sautel  1 , Sung-Joon Min  2 , Joseph T Sakai  2 , Christian Thurstone  3 , Christian Hopfer  2
Affiliations

Trends in fatal motor vehicle crashes before and after marijuana commercialization in Colorado

Stacy Salomonsen-Sautel et al. Drug Alcohol Depend. .

Erratum in

  • Drug Alcohol Depend. 2014 Sep 1;142:360

Abstract

Background: Legal medical marijuana has been commercially available on a widespread basis in Colorado since mid-2009; however, there is a dearth of information about the impact of marijuana commercialization on impaired driving. This study examined if the proportions of drivers in a fatal motor vehicle crash who were marijuana-positive and alcohol-impaired, respectively, have changed in Colorado before and after mid-2009 and then compared changes in Colorado with 34 non-medical marijuana states (NMMS).

Methods: Thirty-six 6-month intervals (1994-2011) from the Fatality Analysis Reporting System were used to examine temporal changes in the proportions of drivers in a fatal motor vehicle crash who were alcohol-impaired (≥0.08 g/dl) and marijuana-positive, respectively. The pre-commercial marijuana time period in Colorado was defined as 1994-June 2009 while July 2009-2011 represented the post-commercialization period.

Results: In Colorado, since mid-2009 when medical marijuana became commercially available and prevalent, the trend became positive in the proportion of drivers in a fatal motor vehicle crash who were marijuana-positive (change in trend, 2.16 (0.45), p<0.0001); in contrast, no significant changes were seen in NMMS. For both Colorado and NMMS, no significant changes were seen in the proportion of drivers in a fatal motor vehicle crash who were alcohol-impaired.

Conclusions: Prevention efforts and policy changes in Colorado are needed to address this concerning trend in marijuana-positive drivers. In addition, education on the risks of marijuana-positive driving needs to be implemented.

Keywords: Alcohol-impaired driving; Drugged driving; Marijuana-positive driving; Medical marijuana; Traffic fatalities.

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Conflict of interest statement

Conflicts of Interest: Dr. Sakai received reimbursement in 2012 for completing a policy review for the WellPoint Office of Medical Policy & Technology Assessment (OMPTA), WellPoint, Inc., Thousand Oaks, CA. He also serves as a board member of the ARTS Foundation. All other authors report no biomedical financial interests or potential conflicts of interest.

Figures

Figure 1
Figure 1
Number of medical marijuana registered users from 2009–2011
Figure 2
Figure 2
Proportion of drivers in a fatal motor vehicle crash who were marijuana-positive in Colorado and 34 states without medical marijuana laws from 1994–2011
Figure 3
Figure 3
Proportion of drivers in a fatal motor vehicle crash who were alcohol-impaired in Colorado and 34 states without medical marijuana laws from 1994–2011
Figure 4
Figure 4
Number of motor vehicle-related fatalities in Colorado from 1994–2011
Figure 5
Figure 5
Number of motor vehicle-related fatalities in 34 states without medical marijuana laws from 1994–2011
See this image and copyright information in PMC

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