The Traffic Injury Research Foundation (TIRF) has published two reports that investigated the behavioural patterns of impaired driving offenders while on an alcohol interlock device.

Research shows that alcohol interlocks reduce recidivism among both first and repeat impaired driving offenders, including persistent offenders, however not much is known about the performance of offenders while on the device. The objectives of Phase 1 of this study were to increase understanding of the behavioural patterns of offenders while on an interlock. In particular, the study examined offender compliance with device requirements and program rules in order to inform the implementation and delivery of interlock programs. This study extended existing knowledge and generated new knowledge that can be utilized by jurisdictions that are considering the implementation of an interlock program or that are considering the expansion of their existing interlock program. Results were used to optimize the Dutch reinforcement scheme for non-compliant behaviour and to inform the allocation of resources for program delivery.

This Phase 1 study was conducted with funding provided by the Dutch Ministry of Transport.

In the second phase of this study, interlock data from impaired driving offenders in three jurisdictions in the United States were examined. The interlock program in each of these jurisdictions included differing levels of monitoring for offenders. The study was designed to replicate findings related to behavioual patterns of interlock offenders, and in particular the “learning curve”. It also examined the profile of compliant and non-compliant offenders, and investigated ways that the length of program participation may impact performance. The study revealed that offenders who are monitored while on the interlock device “learn” to comply more quickly.

Funding for the Phase 2 study was provided by LMG Holdings.