The legalization of marijuana in Washington and Colorado has had no impact on road fatality rates, according to a new study published by the American Journal of Public Health.
Researchers at the University of Texas evaluated “motor vehicle crash fatality rates in the first 2 states with recreational marijuana legalization” and compared them with “motor vehicle crash fatality rates in similar states without recreational marijuana legalization.” They used the US Fatality Analysis Reporting System to determine the annual numbers of motor vehicle crash fatalities between 2009 and 2015 in Washington, Colorado, and 8 control states. They compared “year-over-year changes in motor vehicle crash fatality rates (per billion vehicle miles traveled) before and after recreational marijuana legalization with a difference-in-differences approach that controlled for underlying time trends and state-specific population, economic, and traffic characteristics.”
It was found that; “Pre–recreational marijuana legalization annual changes in motor vehicle crash fatality rates for Washington and Colorado were similar to those for the control states.” Post–recreational marijuana legalization changes in motor vehicle crash fatality rates for Washington and Colorado also did not significantly differ from those for the control states.
Researchers conclude that; “Three years after recreational marijuana legalization, changes in motor vehicle crash fatality rates for Washington and Colorado were not statistically different from those in similar states without recreational marijuana legalization. Future studies over a longer time remain warranted.”
You can find the full text of this study by clicking here.