The leading cause of death among Americans ages 5-34 is traffic fatalities. Alcohol is certainly considered to be a contributing factor. By 2013, nineteen states had passed medical marijuana laws.
This study determined that the first full year following legalization of cannabis (marijuana) that traffic fatalities decline by 8-11%. It is hypothesized that some substitute marijuana use for alcohol consumption.
That observation does not endorse driving under the influence of cannabis.
