The Impact of Mandatory Versus Voluntary Participation in the Alberta Ignition Interlock Program

Research has demonstrated that participation in an interlock program significantly reduces the likelihood of subsequent driving while intoxicated (DWI) convictions at least so long as the interlock device is installed in the vehicle. Despite the growing number of jurisdictions that allow interlock programs and the demonstrated success of these programs, the proportion of DWI offenders who actually have the device installed is minimal. In an effort to increase the proportion of offenders using interlocks, some jurisdictions require offenders to install an interlock as a condition of license reinstatement whereas others merely offer offenders a reduction in the period of hard suspension if they voluntarily participate in an interlock program. The objective of the present study was to determine the extent to which voluntary interlock participants are more or less successful in terms of subsequent recidivism than those for whom interlock program participation has been mandated. The issue was addressed using d...