One out of every nine drivers involved in a fatal car crash in the United States today would test positive for marijuana. That’s the finding of a study from Columbia University’s School of Public Health, which analyzed data on 23,500 drivers involved in fatal crashes from 1999 to 2010.

he report concludes that drug use by drivers is increasing. Drugs were a factor in 12 percent of the deadly crashes in 1999; but drugs were a factor in 28 percent of the lethal crashes in in 2010. Marijuana specifically was involved in only 4 percent of 1999’s fatal wrecks but in 12 percent of 2010’s. Figures for alcohol involvement in fatal crashes didn’t budge through the decade; drinking was a factor in about 40 percent of the deadly traffic mishaps every year.

Dr. Guohua Li, a co-author of the study, told HealthDay News that “If a driver is under the influence of alcohol, their risk of a mortal crash is 13 times higher than the risk of the driver who is not under the influence of alcohol. But if the driver is under the influence of both alcohol and marijuana, their risk increased to 24 times that of a sober person.”

The study, published online in the American Journal of Epidemiology, also reports that no group has a monopoly on increasing marijuana use; the usage rise occurred across all age and ethnic groups and both genders. Jonathan Adkins, deputy executive director of the Governors Highway Safety Association, told HealthDay News that marijuana legalization makes these findings timely to traffic safety officials. “It’s a wake-up call for us in highway safety,” Adkins said.

If you’re arrested and charged with marijuana-related DUI or any DUI charge in California, speak with an experienced DUI defense attorney immediately. Any DUI charge is a real threat to your future, your freedom, and your financial resources. A good DUI defense lawyer will assess your case, compile evidence and witnesses, and work to have your charge reduced or dismissed, or to win an acquittal at trial. Protect your rights and your future; if you’re accused of DUI, speak to an experienced DUI defense attorney immediately.