California Interlock Evaluation TRB: January, 2005 An Evaluation of the Effectiveness of Ignition Interlock in California Report authors: David J., DeYoung, Helen N. Tashima and Scott V. Masten

Traffic Safety Effects of Judicial Orders to Install an IID Outcome DUI convictions DUI incidents Crashes Target Group DUI susp violators N/S SIG: IID % lower !st DUIN/S 2 nd DUIN/S (directional) SIG: IID 13% lower SIG: IID 19% lower

Traffic Safety Effects of Administrative IID Program Outcome DUI convictions DUI incidents Crashes Target Group 2 nd DUIN/S (directional) SIG: IID 41% lower SIG: IID 2.3 x lhigher

Traffic Safety Effects of IID Installation Outcome DUI convictions DUI incidents Crashes Target Group All persons installing IID SIG: IID 18% lower SIG: IID 32% lower SIG: IID 84% higher

Implications: IID Installations u IIDs work when installed –Reduce alcohol-related crashes & convictions u Challenges –Difficult to achieve high installation rates –Installation associated with icreased crash rates

Implications: Judicial Interlock Program u Mixed effects –Reduce alcohol-related crashes & convictions for repeat DUI offenders –Reduces crash rate u Challenges –Does not work for 1 st DUI offenders with high BACs –Does not reduce alcohol-related crashes & convictions for DUI suspension violators

Implications: Administrative Interlock Pgm u Works as intended –Reduce alcohol-related crashes & convictions for repeat DUI offenders installing an IID v Similar to findings from Maryland study u Challenges –Need to increase participation –Program is associated with increased crash rates –need to better control

RECOMMENDATIONS u 1. The Judicial Council should investigate the development of an improved monitoring system for defendants ordered to install an IID

RECOMMENDATIONS u 2. Introduce legislation that would allow repeat DUI offenders who install an IID to reinstate their driver licenses early, after serving their APS suspension, or court-DMV suspension, whichever is shorter

RECOMMENDATIONS u 3. Introduce legislation that would allow peace officers to impound the vehicles of drivers who are restricted to driving IID-equipped vehicles, and who are apprehended driving a vehicle without an interlock device.

RECOMMENDATIONS u 4. Convene a task force comprised of representatives from the courts, DMV, law enforcement, district attorneys, public defenders and ignition interlock providers to investigate barriers to the use of IIDs.

RECOMMENDATIONS u 5. De-emphasize the use of IIDs for first DUI offenders.

RECOMMENDATIONS u 6. Support the current law which requires judges to order DWS-DUI offenders to install an IID

California Interlock Evaluation TRB: January, 2005 An Evaluation of the Effectiveness of Ignition Interlock in California Report authors: David J., DeYoung, Helen N. Tashima and Scott V. Masten