Samenvatting
The effects of alcohol and marihuana, singly and in combination, on driving-related skills were studied with twelve male subjects. All response measures showed significant impairment by marihuana alone and alcohol alone. The combined treatment produced greater impairment than either substance alone. The nature and extent of impairment under alcohol and marihuana is a function of the behaviour examined. The paper discusses these findings in terms of driving skills and traffic safety.