An evaluation of the implementation of ignition interlock in California.
OBJECTIVE
This study evaluates the degree to which courts have implemented California's ignition interlock program, and surveys judges and district/city attorneys to identify barriers to implementing a successful interlock program.


METHODS
There are three parts to the evaluation. In the first, a sample of drivers arrested for driving on a driving under the influence (DUI)-suspended driver license was examined to calculate the rate at which courts order interlocks for DUI-suspended drivers, as required by California law. The second part of the study used Department of Motor Vehicle (DMV) records to count the statewide rate of court-ignition interlock device (IID) orders across time and jurisdictions. The final part surveyed judges, district/city attorneys, and offenders installing an interlock to obtain information about their use of interlock, barriers to implementing an interlock program, and the effectiveness of the devices in preventing drinking and driving.


RESULTS
It was found that conviction rates for driving while suspended are low; that judges order interlocks for only a fraction of the convicted driving-while-suspended (DWS) offenders who should receive such an order; and that the majority of offenders who are ordered by the court to install an ignition interlock in their vehicle do not do so.


CONCLUSIONS
Any successful interlock program will need to find a way to balance the inability of many offenders to pay for the devices, with the need for the industry to remain economically viable.
DeYoung
David J
DJ
California Department of Motor Vehicles, Research and Development Branch, MS F 126, 2415 First Avenue, Sacramento, CA 95818, USA. ddeyoung@dmv.ca.gov
D000428:Alcohol Drinking / Q000331:legislation & jurisprudence*; D001334:Automobile Driving / Q000331:legislation & jurisprudence*; D002140:California; D003625:Data Collection; D005069:Evaluation Studies as Topic; D006801:Humans; D008004:Licensure; D018986:Motor Vehicles; D011482:Protective Devices / Q000706:statistics & numerical data*; D012926:Social Control, Formal / Q000379:methods