Vehicle Impoundment

“In recent years many States have implemented sanctions affecting a DWI offender’s license plate or vehicle. These sanctions are intended to prevent the offender from driving the vehicle while the sanctions are in effect, and also to deter impaired driving by the general public” (UNC Highway Safety Research Center, 2011, p. 1-34). Vehicle impoundment allows seizure and storage of a DWI offender’s vehicle for a designated period of time. The penalty duration varies by state and can be short term (up to 48 hours) or long term (ranges from ten days up to one year), although long-term impoundment laws are more frequently considered in literature about vehicle sanctions (McKnight et al., 2008).

“[NHTSA, 2008h] and [Voas, Fell, et al., 2004] give an overview of vehicle and license plate sanctions and are the basic references for the information provided below. See also Brunson and Knighten, 2005, Practice #4, and [Neuman et al., 2003], Strategies B1, B2, and C1” (UNC Highway Safety Research Center, 2011, p. 1-34).

History

Since the early 1980s, convicted DWI offenders have been subject to ALR laws that suspend the offender’s driving privileges for a period of time. However, offenders may continue to endanger others by driving illegally, an offense known as DWS. Beginning in 1999, the first states began passing vehicle impoundment laws as a way to deter offenders from committing further DWS and DWI violations (Voas and DeYoung, 2002).

Use

As of 2004, vehicle impoundment was used in 22 states (McKnight et al., 2008, Table 1). Of these, 15 states allowed for long-term impoundment. Another seven allowed impoundment on a short-term basis only, to prevent a drunk driver from driving home after an arrest, rather than as a long-term measure (see Table B.8). More-recent updates were not available.

Effectiveness

Six published studies have evaluated vehicle impoundment laws. Of these, three reported positive findings that “[v]ehicle impoundment reduces recidivism while the vehicle is in custody and to a lesser extent after the vehicle has been released” (UNC Highway Safety Research Center, 2011, p. 1-34). Two found relatively little change, and one reported overall reductions in a few traffic safety measures, but these could not be attributed exclusively to vehicle impoundment.

In Ohio, researchers looked at the effect of vehicle impoundment in two counties. One study in Franklin County (Columbus) found a 37.7-percent reduction in DWS recidivism during vehicle impoundment for drivers with previous DWI charges (Voas, Tippetts, and Taylor, 1997). A smaller effect, 27.7 percent, was found in DWI recidivism but was insignificant. The study also found a lasting reduction in recidivism after the vehicle was returned (the length of the penalty period varied from 30 days to 180 days, depending on the number of previous offenses), but this result included the effect of both impoundment and immobilization sanctions. In another study, in Hamilton County (Cincinnati), any driver with any DWS offense or more than one DWI offense is eligible for vehicle impoundment. Voas, Tippetts, and Taylor, 1998, found 40-percent reductions in DWS and DWI offenses for the impounded group during the penalty period and 25-percent reductions approximately one year after impoundment. This postpenalty effect was larger (56 to 58 percent) for the drivers whose cars were impounded due to second and third DWI offenses—possibly because these drivers were not reclaiming their cars.

Similar results were found in California. DeYoung, 1999, studied the specific deterrence effect that California’s impoundment law had on drivers with suspended or revoked licenses (S/Rs). This evaluation found that both first-time and repeat S/R drivers whose vehicles were impounded had fewer subsequent DWS convictions, moving-violation convictions, and crashes than those in similar control groups whose violations occurred the year before the law went into effect. The effect of impoundment, relative to the control group, was larger for repeat S/R drivers. This study was not limited to drivers with alcohol offenses, and the reason for drivers’ S/R status was not provided; however, it is likely that many of the S/R orders result from repeat DWI convictions.

Researchers also examined the effect that California’s impoundment law had on multiple safety outcomes in the city of Upland (Cooper, Chira-Chivala, and Gillen, 2000) using crash and citation data from one year before implementation up to 4.5 years after implementation. This study did not track individual violators over time. Time-series analyses found slight reductions in DWI offenses, driving without a valid license, and traffic crashes (includes fatal and nonfatal injury, hit-and-run, and speed-related crashes). The authors suggest that these outcomes are the result of the continued, long-term, and strict enforcement of the impound law in the city.

Two studies were less conclusive about effectiveness of impoundment laws. In a separate analysis of the California impoundment law, DeYoung, 2000, examined the general deterrent effect by examining crash rates of both S/R drivers and non-S/R drivers using time-series analysis (autoregressive integrated moving average [ARIMA] models). The crash rates for both groups decreased after the vehicle impoundment law went into effect (13.6 percent for the S/R drivers and 8.3 percent for control drivers), but these effects quickly lessened over time and were almost completely gone after one year. The authors found no compelling evidence of a general deterrent impact of the impoundment law.

A study in Manitoba, Canada, by Beirness, Simpson, et al., 1997, as cited in Voas and DeYoung, 2002, found a decline in both fatal crashes and nighttime single-car crashes for DWS drivers after an impoundment law and ALS law went into effect.⁴¹ The authors were unable to attribute causality of their findings because of the simultaneous introduction of the two laws.

Costs

The strategy is costly, as storage fees can be $20 daily and owners may abandon low-value vehicles rather than pay substantial storage costs, [in which case the locality is responsible for the storage and towing costs] ([Neuman et al., 2003], Strategy C1; [NTSB, 2000]). In California, impoundment programs are administered largely by towing contractors and supported by fees paid when drivers reclaim their vehicles or by the sale of unclaimed vehicles. (UNC Highway Safety Research Center, 2011, pp. 1-34–1-35)

Measuring Effectiveness

The effectiveness of vehicle impoundment laws is generally measured in terms of recidivism expressed as the percentage of offenders who drive while unlicensed (DWU) or suspended (DWS) or have alcohol-related traffic violations after being sanctioned. Crash rates are another common outcome of interest in impoundment studies.

Time to Implement

Specific information on implementing vehicle impoundment is not available; however, “vehicle and license plate sanctions require at least several months to implement” (UNC Highway Safety Research Center, 2011, p. 1-34).

Other Issues

To Whom Vehicle Sanctions Are Applied

Vehicle impoundment policies vary by state, but “most vehicle sanctions have been applied to repeat [DWI] offenders” or those with DWS convictions following a DWI offense (UNC Highway Safety Research Center, 2011, p. 1-35). “[S]ome States also apply vehicle sanctions to high-BAC first offenders (e.g., a BAC of .15 or higher)” or first offenders but with a shorter penalty period (UNC Highway Safety Research Center, 2011, p. 1-35). “If someone other than the offender owns the vehicle, the vehicle owner should be required to sign an affidavit stating they will not allow the offender to drive the vehicle while the suspension is in effect ([NHTSA, 2008h])” (UNC Highway Safety Research Center, 2011, p. 1-35).

Administrative Issues

All license plate and vehicle sanctions require an administrative structure to process the license plates or vehicles. [If laws] permit officers to impound vehicles . . . at the time of arrest [rather than waiting for a court-issued order, this reduces] the opportunity [for offenders] to . . . transfer vehicle ownership ([NHTSA, 2008h]). (UNC Highway Safety Research Center, 2011, p. 1-35)

Table B.8. Vehicle Impoundment Laws, as of December 2004

SOURCE: McKnight et al., 2008.

 

Footnotes

41. The duration of the study period was not provided.