This project will produce an interactive program designed to reduce the incidence of driving under the influence of alcohol (DUI). The program will be worksite-based and available via Internet or CD-ROM/DVD. For each user, the program will gather demographic, cognitive decision-making, and behavioral information, and then customize the intervention to the individual. Program users will be diagnosed into one of three categories: (a)"Naive Risk-Takers," (b)"Cognitive Risk-Takers," (who are non-alcoholics), and (c) alcoholics. Employees diagnosed as alcoholics will be tactfully directed to professional treatment resources. Program components will include education, video behavioral modeling, video testimonials, driving impairment simulations, a virtual blood-alcohol calculator, and strategies to overcome barriers to reducing risk. It will provide social support and encourage user commitments to specific risk-reduction strategies. In Phase I, diagnostic and prescriptive DUI prevention strategies for males 21-35 years old will be developed. This prototype program will be evaluated in a randomized trial. In Phase II, the program will be expanded to target four subgroups (young and older males and females), and it will include support and education for "concerned others" who want to help prevent DUI behavior. The program will be evaluated in a large-scale randomized trial. [unreadable] [unreadable]