An estimated 28 000 lives are lost on Europe’s roads every year and a further 1.34 million people are injured (1). Many of these accidents and deaths are caused by drivers whose performance is impaired by a psychoactive substance. Alcohol remains the number one substance endangering lives on European roads, but use of drugs and medicines behind the wheel, particularly when combined with alcohol, is a major challenge for policymakers. In a new report out today, Drug use, impaired driving and traffic accidents, the EU drugs agency (EMCDDA) reviews the latest research in this field (2).