Reducing impaired driving requires a systematic, consistent, and multifaceted approach. There is strong evidence on the effectiveness of both direct and indirect measures. The strategy that has the most immediate and largest impact has been highly publicized, visible, and frequent impaired-driving enforcement, especially deploying sobriety checkpoints or random breath testing. Lowering legal blood alcohol concentration (BAC) limits for driving to 0.05 g/dL or lower has also had a world-wide impact. Raising the legal drinking age has been successful in the US and other countries in reducing young impaired-driver fatal crashes. Graduated drivers' licensing for youth has also been effective by restricting conditions under which youth can drive. Sanctions that reduce impaired-driving recidivism include special driving-under-the-influence (DUI)/driving-while-intoxicated (DWI) courts, mandatory alcohol ignition interlocks, and consistent alcohol-monitoring programs. Opportunities for further progress include better enforcement of the drinking age and refusing to serve obviously intoxicated patrons. Technology for detecting alcohol impairment and autonomous vehicles will also play an important role in future efforts to eliminate impaired driving.