The alcohol ignition interlock program began operating in Québec in December 1997. Someone convicted of driving while impaired (DWI) is allowed under the program to drive a vehicle on condition it be equipped with an ignition interlock, and the individual's voluntary participation allows for a shortening of the period of licence revocation. This evaluation seeks to measure the program's impact on both DWI recidivism and crashes. The methodology is a cohort study comparing a group comprised of individuals convicted of DWI who took part in the ignition interlock program, and a control group made up of drivers convicted during the same period who did not participate. The data concerning first-time DWI offenders and that pertaining to repeat offenders is presented separately. Participation in the interlock program resulted in a reduction in the repeat DWI rate by 80% during the first 12 months for first-time offenders and by 74% during the first 24 months among repeat offenders. Figures for night crashes involving no more than one vehicle, when compared to overall crash data, also tend to show the effectiveness of the program in lowering the incidence of impaired-driving mishaps. In both cases, however, the effect tends to disappear after removal of the interlock, which leads to the conclusion that it serves more as a restraining device than a tool for driver rehabilitation. This suggests that extending the period of interlock use should be considered, at least for drivers who are likely to become repeat DWI (Author/publisher) For the covering abstract of the conference see ITRD Abstract No. E201067.
Abstract