The following targeted jurisdictions were selected for their strict penalties and consistent enforcement of mandatory confinement for drunk driving: Seattle, Wash.; Memphis/Shelby County, Tenn.; Cincinnati/Hamilton County, Ohio; Minneapolis/Hennepin County, Minn.; and selected California counties. The study encompassed periods in the late 1970's and early 1980's. Data were obtained from agency and court records as well as from interviews with personnel of agencies concerned with drunk driving and traffic safety. Data on alcohol-related accidents were examined in relation to mandatory confinement. In two of the jurisdictions, alcohol-related accidents decreased following the implementation of strict sanctions. This was not true of the other jurisdictions. Drunk driving arrests increased after the enactment of mandatory confinement, and more of those convicted of drunk driving were incarcerated, even first-time offenders. Jails introduced new programs, facilities, procedures, and personnel to deal with the influx of drunk-driving offenders. Probation services were overloaded. Recommendations pertain to planning prior to the implementation of mandatory confinement, including the need for additional resources and processing procedures. Tabular data and 8 references.