WIP provides a therapeutic alternative to incarceration for persons convicted in a municipal or county court of an alcohol- or drug-related vehicular offense. Program effectiveness was evaluated with offenders adjudicated by courts in the 11 Ohio counties surrounding Dayton. Recidivism for three groups was examined in terms of prior offense status, license suspension action, court assignment pattern, age, sex, and blood alcohol concentration at the time of arrest. Repeat offenders consistently did worse than first- time offenders, but, with repeaters, the WIP group did better than the comparison groups of jail and suspended sentence/fine. The WIP group exhibited a lower recidivism rate than the other two groups and a longer average survival time (in days) in courts than mandated offenders. Other research has corroborated the effectiveness of this model for enhancing treatment compliance. 1 figure and 47 references