Effectiveness of Ignition Interlocks for Preventing Alcohol-Impaired Driving and Alcohol-Related Crashes: A Community Guide Systematic Review

  • Published: Am. J. Prev. Med., 40(3), 362-376, 2011
  • Authors: R.W. Elder, R. Voas, D. Beirness, R.A. Shults, D.A. Sleet, J.L. Nichols, and R. Compton
  • Date Added: 28 Mar 2013
  • Last Update: 28 Mar 2013
  • Format: pdf


To assess the effectiveness of alcohol ignition interlocks for reducing alcohol-impaired driving and alcohol-related crashes among those who have been arrested or convicted for alcohol-impaired driving.


Systematic review, conducted according to the methods developed for the Guide to Community Preventive Services. Incorporates Cochrane review conducted by Willis et al in 2004 (see separate reference). The majority of the interlock programs were applied to offenders who had multiple offences or high blood alcohol concentrations. The reviewed studies tended to compare offenders who had interlocks installed with a comparison group of offenders who did not have interlocks (but received licence disqualification instead). N=15 studies included.

Key Findings:

  • Two studies evaluating the effectiveness of an interlock program in New Mexico found that the devices were associated with a 65 per cent lower risk of recidivism among repeat offenders, and a 61 per cent lower risk among first-time offenders.

  • Overall, the installation of ignition interlocks (in non-UK programs) was associated with large reductions in re-arrest rates for alcohol-impaired driving.

  • Following removal of the interlocks, re-arrest rates reverted to levels similar to those for comparison groups.

  • Limited evidence from studies that used crash rates as an outcome measure suggests that alcohol-related crashes decrease while interlocks are installed in vehicles.


Alcohol ignition interlocks, alcohol impaired driving, crashes, effectiveness.


Review of international studies. There is risk of bias in comparing the groups identified in the methodology – interlock groups tend to be older, drive more, have higher incomes, and have more offences.