Marijuana Use and Motor Vehicle Crahses

Open Access
Author:
Li, Mu-chen
Area of Honors:
Statistics
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • David Russell Hunter, Thesis Supervisor
  • John Fricks, Honors Advisor
Keywords:
  • Crashes
  • Traffic
  • Automobile
  • Risk
  • Marijuana
  • Cannabis
  • Meta-anaysis
Abstract:
Legalization of marijuana has been a topic of debate for decades. Advocates for legalization argue that marijuana has many medical applications and that legalization would lead to increased tax revenue, but the opposition to marijuana legalization points to the many negative effects of marijuana use, as well as the undesirable consequences of legalization. The recent legalization of marijuana for both recreational and medicinal purposes in Colorado and Washington has increased interest in this debate. To better inform the debate over legalization of marijuana, this study was done to investigate the relationship between marijuana use and motor vehicle crash risk. Many previous studies have been done on this topic but have yielded conflicting results. This new study conducts a meta-analysis in order to use the previous studies and produce a statistically significant result. It was hypothesized that marijuana use would be positively correlated with higher motor vehicle crash risk. The results of the meta-analysis confirm the hypothesis. The mean odds ratio using the random effects model for crash risk of drivers who tested positive for marijuana use versus drivers who tested negative was found to be 2.24 (95% CI = 1.45 to 3.47). Using the random effects model for crash culpability, a mean odds ratio of drivers who tested positive for marijuana use versus drivers who tested negative of 1.72 (95% CI = 1.19 to 2.48) was calculated. Therefore, there is a statistically significant positive association between marijuana use and motor vehicle crashes.