Twenty epidemiological studies and reviews explore the dimensions of the problems of alcohol and other drugs in relation to highway safety and discuss the identification of groups at high risk of involvement in alcohol-related automobile accidents. Twelve pharmacological and behavioral studies and reviews examine such topics as the effects of alcohol on skilled performance, the effects of sedative drugs on human performance, and interpretations of breathalyzer tests for medicolegal purposes. Twelve papers examine and evaluate methods for measuring the presence of alcohol; the use of breath, blood, urine, and saliva tests is discussed. Eight papers evaluate potential countermeasures, focusing on the Swedish experience with drunken driving, community programs, specialists' attitudes toward current countermeasures, and drivers' attitudes toward police measures against drinking and driving. Papers on legislation, enforcement, and deterrence examine legislative and enforcement experiences in England, the United States, the Netherlands, and Great Britain; court systems for handling drinking drivers, and treatment programs for youths and adults. Ten papers on education and information describe public information programs and efforts to evaluate their effectiveness. Conference resolutions and an author index are also provided. Most papers include tabular and graphic information, charts, and references.