This report considers the ideal methods for a scientifically rigorous evaluation of the possible road safety benefits of breath alcohol ignition interlock devices. It is hoped that the core methodology suggested by this research will allow appropriate and consistent evaluation of an Interlock Program wherever it is implemented. The report briefly reviews the relevant literature on alcohol interlocks and program implementation and then recommends both process and outcome evaluation design methodologies. A range of possible methods of evaluation are considered in relation to the following decision areas: target population, methods of group assignment, the type of program evaluated, design of the outcome evaluation, design of the process evaluation and the choice of variables used. Issues and problems which may pose some difficulties for the rigour of the evaluation are discussed, and the recommended options are compared with available alternatives. Within each of these decision areas specific alternatives are recommended, and methods for making the most effective use of these alternatives are considered. Finally, sample size, privacy issues, and the time of fitting an interlock are considered. (Author/publisher)
Abstract