This study presents a general deterrence evaluation of the ignition interlock pilot program mandated by Assembly Bill 91 for the counties of Alameda, Los Angeles, Sacramento, and Tulare during the period of July 1, 2010 through January 1, 2016. This pilot program requires convicted first and repeat DUI offenders to install an III) on all vehicles they own or operate for a pre-specified time period in order to obtain a restricted, reissued, or reinstated driver's license. The present study analyses DUI conviction data from July 2007 through June 2013. The results indicate that IID installation rates among all DUI offenders increased dramatically in the pilot counties from 2.1% during the pre-pilot period to 42.4% during the pilot period. The results of the Auto-Regressive Integrated Moving Average (ARIMA) analyses show that the III) pilot program was not associated with a reduction in the number of first-time and repeat DUI convictions in the pilot counties. In other words, no evidence was found that the pilot program has a general deterrence effect. A follow-up study is being conducted to determine if the pilot program has any specific deterrence effects. It is recommended that any subsequent legislative action on this subject take into consideration the findings of this specific deterrence evaluation. This evaluation is anticipated to be completed in the fall of 2015. (Author/publisher)
Abstract