There is strong evidence that drugged driving is a serious public health and safety problem in the United States and that current efforts to combat it are seriously inadequate. Now is the time to expand the drugged driving knowledge base in order to guide the development of more effective policies, laws, and programs. Research recommendations are to evaluate impaired driving laws, assess and improve drugged-driving data collection, improve drugged driving education, identify and evaluate promising models for drugged driver identification, standardize drugged driver testing, conduct drug impairment research, conduct drugged driving behavioral research, and conduct related treatment research. 174 references and appended excerpts from the 2010 National Drug Control Strategy