Marijuana And Drugged Driving

  • Underage college students who used marijuana are 6.24 more likely to drive after
    marijuana use compared with those using only alcohol.1
  • Driving under the influence of cannabis was associated with a significantly increased risk of motor vehicle collisions compared with non-users by as much as 2-4 fold. 2,3,4
  • Risk of fatal traffic crashes while driving under the influence of cannabis has a significant causal relationship. 5
  • Since medical marijuana became commercially available in Colorado, mid-2009, there was an increase in the proportion of marijuana-positive drivers involved in a fatal motor vehicle crash from 5.9% in the first 6 months of 2009 to 10% at the end of 2011. No significant changes were seen for alcohol-impaired drivers involved in a fatal motor vehicle crash during the same period. 6
  • Using alcohol with marijuana results in greater driving impairment than the sole use of either drug. 7

References:

  1. Whitehill JM, Rivara FP, Morena MA. Marijuana-using drivers, alcohol-using drivers, and their passengers: prevalence and risk factors among underage college students. JAMA Pediatr. 168(7):618-624,2014
  2. Asbridge M1, Hayden JA, Cartwright JL. Acute cannabis consumption and motor vehicle collision risk: systematic review of observational studies and meta-analysis. BMJ. 344: e536, 2012 Asbridge M, Mann R, Cusimano MD, Trayling C, Roerecke M, Tallon JM, Whipp A, Rehm J. Cannabis and traffic collision risk: findings from a case-crossover study of injured drivers presenting to emergency departments. Int J Public Health.59(2):395-404, 2014
  3. Fergusson DM, Horwood LJ, Boden JM. Is driving under the influence of cannabis becoming a greater risk to driver safety than drink driving? Findings from a longitudinal study. Accid Anal Prev. 40(4):1345-50, 2008
  4. Laumon B, Gadegbeku B, Martin JL, Biecheler MB; SAM Group. Cannabis intoxication and fatal road crashes in France: population based case-control study. BMJ. 331(7529):1371, 2005 Salomonsen-Sautel S, Min SJ, Sakai JT, Thurstone C, Hopfer C. Trends in fatal motor vehicle crashes before and after marijuana commercialization in Colorado. Drug Alcohol Depend 140: 137-44, 2014
  5. Sewell RA, Poling J, Sofuoglu M. The effect of cannabis compared with alcohol on driving. Am J Addict. 18(3):185-93, 2009

Prepared by the Marijuana Science Forum, Oct. 2014

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