Program Profile: Hamilton County (Ohio) Ignition Interlock Device Program

This program was designed to reduce driving under the influence (DUI) through installation of an ignition interlock device in motor vehicles of drivers convicted of alcohol-related traffic violations. The program is rated Promising. The treatment group had a statistically significant lower likelihood of being rearrested for DUIs, compared with comparison group participants, who served the typical license suspension and probation period.

A Promising rating implies that implementing the program may result in the intended outcome(s).

A Promising rating implies that implementing the program may result in the intended outcome(s).

Program Goals/Target Population

Hamilton County, Ohio, introduced this ignition interlock program to deter repeated drunk driving arrests in persons convicted of driving under the influence (DUI). Participants were selected if they had received a conviction for DUI and were a) a person convicted for the first time with a blood–alcohol content (BAC) of 0.20 or higher at arrest, b) someone convicted of DUI two or more times within the last 10 years, or c) a person who refused a BAC test at the time of arrest.

Breath analyzer ignition interlock devices have become popular across the Nation as a way to combat alcohol-related vehicular accidents. As of April 2009, 47 States and the District of Columbia had introduced the use of interlock programs (Rauch, et al. 2011).

Program Components

Judges offered individuals who fit the target profile the opportunity to participate in the interlock program, which restored limited driving privileges contingent on the use of an interlock-equipped vehicle. They had the chance to refuse participation; these person served their original court-ordered license suspension and probation period.

The interlock connects the vehicle’s ignition system to a breath analyzer. Before the person can start the car, the individual must breathe into the device, which is calibrated to “lock” the ignition if the breath–alcohol level exceeds a preprogrammed level (often 0.025). The devices also are programmed for “rolling retests” at intervals while the car is in operation. If the driver fails one of these tests, the device triggers the horn and flashing lights, which will continue to attract notice until the car is turned off.

Program Theory

To the extent that a theory grounds the use of interlock devices, routine activity theory may apply (see Rauch et al. 2011). This theory predicts that crime increases when motivated person find suitable targets that lack capable guardians. The interlock device in this perspective acts as a way to remove a suitable target (a drivable car) from a motivated persons (the alcohol-impaired driver). It also acts as a “guardian” to prevent the crime of operating a vehicle while under the influence.

Some researchers also refer to learning theory to explain the presence or absence of changed behavior after the device is removed from the vehicle (see Rauch et al. 2011). The theory suggests that people must “unlearn” the drinking behavior and then have to be repeatedly “rewarded” by successful driving episodes (that is, not being caught while driving intoxicated). If the device is installed too briefly, they do not have a sufficient period to unlearn their previous behaviors. If the device is installed for longer, the driver is conditioned to learn about the negative effect (that drinking is “punished” by the inability to start the car).

Study

Morse and Elliot (1992) used a quasi-experimental design with a comparison group to examine the effects of ignition interlock devices on rearrests for driving under the influence (DUI). Participants for the study were drawn from persons convicted of DUIs in Hamilton County, Ohio, between 1987 and 1989. Subjects were selected in two stages. In the first stage, judges could offer people who met the eligibility criteria the option of participating in the program. Those eligible included

• All first-time offenders with a blood–alcohol content (BAC) of 0.20 or higher at arrest
• Repeat offenders convicted of DUI two or more times within the past 10 years
• People who refused a BAC test at the time of their arrest

In the second stage, these individuals could choose to participate in the treatment group with a license restricted to a device-equipped vehicle or decline an interlock device and instead serve the original suspension and probation period. The comparison group comprised participants who chose to serve the usual suspension and probation period. The two groups demonstrated the presence of selection bias, but efforts were made in the analysis to take that bias into account. Researchers used a procedure that matched subjects on three factors: 1) problem drinker classification, 2) number of prior alcohol/drug-related arrests, and 3) number of prior DUI arrests. This process yielded 273 individually matched pairs. The overall sample (n = 546) was 87.9 percent male and 12.1 percent female. The interlock treatment group was 87.3 percent White, 12.7 percent non-White, and had an average age of 37.2 years. The license suspension comparison group was 73.7 percent White, 26.3 percent non-White, and had an average age of 35.6 years.

The outcome of interest was rearrest for DUI in Hamilton County, and the difference between the treatment and comparison groups was determined by a time-to-failure analysis. The analysis examined a period of 30 months. No subgroup analyses were conducted.

These sources were used in the development of the program profile:

These sources were used in the development of the program profile:

Beck, Kenneth H., William J. Rauch, Elizabeth A. Baker, and Allan F. Williams. 1999. “Effects of Ignition Interlock License Restrictions on Drivers With Multiple Alcohol Offenses: A Randomized Trial in Maryland.” American Journal of Public Health 1696–1700.

Elder, Randy W., Robert B. Voas, Doug Beirness, Ruth A. Shults, David A. Sleet, James L. Nichols, and Richard Compton (Task Force on Community Preventive Services). 2011. “Effectiveness of Ignition Interlocks for Preventing Alcohol-Impaired Driving and Alcohol-Related Crashes: A Community Guide Systematic Review.” American Journal of Preventive Medicine 40(3):362–76.

Magnusson, Patrick, Lisa Jakobsson, and Sven Hultman. 2011. “Alcohol Interlock Systems in Sweden: 10 Years of Systematic Work.” American Journal of Preventive Medicine 40(3):378–79.

Raub, Richard A., Roy E. Lucke, and Richard I. Wark. 2001. Illinois Secretary of State’s Breath Alcohol Ignition Interlock Device Program: Final Report, Vol. 2: Pilot Implementation Evaluation. Evanston, Ill.: Northwestern University, Center for Public Safety.

Rauch, William J., Eileen M. Ahlin, Paul L. Zador, Jan M. Howard, and G. Doug Duncan. 2011. “Effects of Administrative Ignition Interlock License Restrictions on Drivers With Multiple Alcohol Offenses.” Journal of Experimental Criminology 7(2):127–48.

Task Force on Community Preventive Services. 2011. “Recommendations on the Effectiveness of Ignition Interlocks for Preventing Alcohol-Impaired Driving and Alcohol-Related Crashes.” American Journal of Preventive Medicine 40(3):377.

Zador, Paul L., Eileen M. Ahlin, William J. Rauch, Jan M. Howard, and G. Doug Duncan. 2011. “The Effects of Closer Monitoring on Driver Compliance With Interlock Restrictions.” Accident Analysis and Prevention 43(6):1960–67.