The first part of a two-part, two volume study deals with adults aged 18-55 and identifies target populations and communications strategies for encouraging personal action steps to prevent drunk driving. Fully 54% of adult Americans participate once a month in social or business situations where alcohol is served. They are termed Alcohol Related Situations(ARS)-Involved. This group has the potential for controlling drinking or restraining drunk drivers. The types of measures they are willing to take are restricted to friends and relatives, and include offering to drive, inviting the person to stay over, calling a taxi, and serving food with liquor. Findings, reported largely in tabular form, and recommendations are based on personal interviews with a national probability sample of 1,600 adults. Target populations for advertising are differentiated on the basis of life styles and personality profiles. A Technical Appendix contains: Schematic Flow Chart of Study Operations, Sample Design and Field Procedures, Sample Weighting, Sample Tolerances, U.S. Population Estimates, R Factor Analysis, Q Segmentation Analysis, Validation of Q Analysis, Development of Personality Scores, Fact and Attitude Battery--Full Scale, and a 21-item bibliography. Also included are copies of the interview forms. (NTIS)