The State of Florida has legalized marijuana for medical purposes. Marijuana has now been legalized for medical use in 28 states.
We know that marijuana and or alcohol impairs ones driving ability. Surprisingly, the traffic fatality rate dropped by an average of 11% in states that have legalized medical marijuana since 1996. At the moment researchers have no explanation for this finding. They believe marijuana users stay home off the road and use their medication while individuals drinking alcohol are more likely to drive to or from an establishment serving alcohol.
The state of Colorado has legalized marijuana for general recreational use. They do not yet have data on traffic fatalities and marijuana usage.