CBS News: “According to a recent study, fatal car crashes involving pot use have tripled in the U.S. “Currently, one of nine drivers involved in fatal crashes would test positive for marijuana,” Dr. Guohua Li, director of the Center for Injury Epidemiology and Prevention at Columbia, and co-author of the study told HealthDay News. . . . Drugged driving accounted for more than 28 percent of traffic deaths in 2010, which is 16 percent more than it was in 1999.”