Research Notes- Spring 1998
Vehicle Impoundment Law Found Effective
David J. DeYoung
Suspended/revoked (S/R) and unlicensed drivers have long been a source of concern to traffic safety professionals. While it is known that license actions, such as suspension and revocation, do reduce the traffic risk posed by problem drivers, it is also known that most S/R drivers continue to drive and to pose an increased safety risk. In short, there is significant room to improve the effectiveness of license suspension and revocation. A recently published DMV study indicates that the vehicle impoundment and forfeiture laws are one means of improving the effectiveness of license suspension/revocation.
Beginning in January 1995, S/R and unlicensed drivers found violating their illegal driving status are subject to having their vehicles towed and impounded for 30 days. In addition, if the driver is the registered owner of the vehicle, and has a prior conviction for driving while unlicensed or suspended/revoked, the vehicle is subject to forfeiture.
In order to determine whether these new impoundment and forfeiture laws are effective, the Research & Development Branch has undertaken two separate evaluation studies of the laws. The first study is an analysis of the general deterrent effects of the laws. General deterrence refers to how the perception of the consequences for violating a law shapes the behavior of all persons in a position to violate it. In the case of vehicle impoundment/forfeiture, the general deterrent analysis will examine whether simply the threat of impounding or forfeiting vehicles deters all suspended/revoked and unlicensed drivers in the state from violating their invalid driving status, and accruing traffic convictions and becoming involved in crashes. This analysis is just beginning, and the results will be available later this year.
The second study, which has recently been completed and is the subject of this article, analyzes the specific deterrent effect of vehicle impoundment. Specific deterrence refers to the effect of the law on the subsequent behavior of those who are apprehended and sanctioned for violating it. The specific deterrent analysis was designed to find out whether impounding vehicles reduces the subsequent rates of illegal driving and crashes.
The study compared the 1-year subsequent driving behavior of more than 6,300 suspended/revoked and unlicensed drivers whose vehicles were impounded, with about the same number of such drivers whose vehicles were not impounded. The effectiveness of impoundment was evaluated using three measures of subsequent driving: driving-while-suspended (DWS)/driving-while-unlicensed (DWU) convictions, total traffic convictions, and crashes.
Subsequent DWS/DWU Convictions
First offenders whose vehicles were impounded had an average rate of subsequent DWS/DWU convictions that was 24% lower than first offenders whose vehicles were not impounded. These positive effects of impoundment were even greater for repeat offenders. Repeat S/R offenders in the impound group had 34% fewer DWS/DWU convictions than their counterparts in the non-impound group. These findings are summarized in the figure below.
Subsequent Traffic Convictions
Impoundment was also effective in reducing subsequent traffic convictions among suspended/revoked and unlicensed drivers. The average rate of subsequent traffic convictions (of all types) for impounded first offenders was 18% lower than the rate for non-impounded first offenders. And, as can be seen from the figure below, the differences were even more striking for repeat offenders. Repeat offenders whose vehicles were impounded had 22% fewer traffic convictions than non-impounded repeat offenders.
Subsequent Crashes
As with convictions, vehicle impoundment proved to be effective in reducing crashes as well. Impoundment was associated with a 25% reduction in crashes for first offenders, and a 38% reduction for repeat offenders. These results are shown in the figure below.
Conclusions
The study shows that vehicle impoundment is having a positive effect on traffic safety in California. Importantly, it appears even more effective for repeat offenders—those whose high-risk driving has traditionally been resistant to change—than for first offenders. These findings provide strong support for the use of vehicle impoundment for suspended/revoked and unlicensed drivers. In addition, because most law enforcement agencies charge administrative fees at the time they release vehicles from impoundment, the use of vehicle impoundment is a cost-effective means to enhance traffic safety in California.
To order a copy of the report An Evaluation of the Specific Deterrent Effect of Vehicle Impoundment on Suspended, Revoked and Unlicensed Drivers in California write to DMV, Research and Development Branch at 2415 1st Avenue, Mail Station F-126, Sacramento, CA 95818, Fax No. (916) 657-8589, or by e-mail: dluong@dmv.ca.gov