A study released by a professor from the University of Colorado-Denver presents some interesting findings about the rate drunk driving accidents in states that have legalized medicinal marijuana, as Colorado has. It turns out that marijuana use may actually reduce the number of deaths due to car accidents.

The study examined accident data compiled in the 16 states, plus the District of Columbia, where medical marijuana has been legalized sometime since the mid-1990s. Looking at the trends from 1990 through 2009, the number of people killed in accidents involving alcohol went down an average of 12 percent after marijuana became legal for medicinal use. Cases of a very drunk driver getting involved in a fatal crash went down 14 percent. And the overall number of fatal car accidents dropped 9 percent in those states.

The author found that the rate of accidents dropped 13 percent for men, compared with 9 percent for female drivers. That appears to parallel the fact that more men receive prescriptions for marijuana than women.

While the findings may be surprising to some, other studies have shown that driving under the effects of marijuana is safer than drunk driving. One possible reason is that people tend to smoke marijuana at home, whereas alcohol is often consumed at bars and restaurants, requiring the drinker to get back home. Another theory is that people high on marijuana tend to be more aware of its effects and concentrate on driving. Drinkers, on the other hand, tend to be overconfident in their driving abilities.

Source: TIME, "Why Medical Marijuana Laws Reduce Traffic Deaths," Maia Szalavitz, Dec. 2, 2011