In a recent study conducted by two university professors, car accident fatalities are shown to have decreased in those states that have legalized marijuana laws. The information linking those states was posted on the Institute for the Study of Labor website and is currently under review by the Journal of Law and Economics.
The data was gathered by D. Mark Anderson, an economics professor at Montana State University, and Daniel Rees, a professor at the University of Colorado Denver. The individual state data was derived from the National Survey on Drug Use and Health, which, along with other data sources, determined a nine percent reduction in traffic accident fatalities in the states that have legalized marijuana laws.
Sixteen states currently have legalized medical marijuana. Although Ohio is not included, it currently has a citizen-initiated amendment to its Constitution that is scheduled for a ballot vote this year. Pennsylvania and Illinois also have pending legislation, and Michigan has had a legalized marijuana law since 2008. States that do have legalized marijuana report decreases in car accident deaths.
The researchers both said they are surprised at the results from the study. They believe the results could be because young people and adults are consuming less alcohol in favor of legalized marijuana. They agree that while the study results do not prove that smoking marijuana impairs drivers any less than alcohol, it is a possibility.
The research does have it critics. Discover magazine posted that the evidence is not definitive and that the study did not compare the same statistics among states that do not have legalized marijuana.
Source: Huffington Post, "States that legalized medical marijuana saw fewer traffic deaths, study says" Dec. 30, 2011