Researchers from Columbia University's Mailman School of Public Health have found an 11 percent drop on average in the District of Columbia as well as the 23 states with legalized medical marijuana, reports the Washington Post.

The reduced traffic fatalities mostly occurred for motorists between the ages of 15-44, a group containing a high percentage of registered medical cannabis users. Specifically, researchers observed an 11 percent reduction of among ages 15 to 24, and 12 percent for ages 25 to 44.

A 9 percent drop was also observed among the 45 and over crowd, whose number of registered medical marijuana patients continues to grow.

"We found evidence that states with the marijuana laws in place compared with those which did not, reported, on average, lower rates of drivers endorsing driving after having too many drinks," said Silvia Martins, MD, PhD, associate professor at the Mailman School and the study's senior author. "We can also point to other characteristics such as the strength of public health laws related to driving, infrastructure characteristics, or the quality of health care systems, as a partial explanation for these findings."