[Ken H]

Here are the traffic fatality rates by state for 2013. Note that Colorado, Washington, and Oregon were below the national average, which was 1.11 deaths per 100 million vehicle miles traveled. DC, which has medical marijuana and just voted 2 to 1 to legalize, had the lowest rate in the country.

Also note that medical mj states, for the most part, appear to have safer highways than states without.

http://www.iihs.org/iihs/topics/t/general-statistics/fatalityfacts/state-by-state-overview

[Mastador1]

http://consumer.healthday.com/public-health-information-30/marijuana-news-759/fatal-car-crashes-involving-pot-use-have-tripled-in-u-s-study-684515.html