Whitehill et al1 share the findings of a survey of 315 first-year college students who report having driven after using marijuana and/or alcohol and being a passenger of a driver who had used these substances. They found that among first-year college students who had used marijuana in the past month, a substantial proportion reported driving after using marijuana (43.9% of male and 8.7% of female students). Of particular interest, although a higher proportion of students had drunk alcohol in the past month, rates of driving were much lower after drinking than after marijuana use. Study findings speak to the changing nature of impaired driving and bring needed attention to the issue of marijuana use before getting behind the wheel.