Requiring treatment for interlock violators reduces re-arrest rates

February 1, 2017


Alcohol-impaired driving offenders in interlock programs are less likely to reoffend after their interlocks are removed if they have been referred for treatment, a study funded by the Centers for Disease Control and Prevention concludes.

Interlocks are breath-testing units attached to a vehicle's ignition. They prevent a vehicle from starting until a driver blows into the unit and gets a negative reading for alcohol. Requiring offenders to install interlocks before they regain full driving privileges has been shown to reduce recidivism. State laws that mandate interlocks for everyone convicted of drinking and driving have been estimated to reduce alcohol-involved crash deaths by 15 percent (see "Interlocks cut alcohol-related crash deaths," May 24, 2016).

Currently, 28 states, the District of Columbia and four California counties require interlocks for all offenders. California recently expanded the requirement to the entire state beginning in January 2019.

While an interlock can keep a person from drinking and driving, once it is removed, many people reoffend. The authors of the latest study wanted to see if enrolling people in treatment programs could extend the benefit beyond the interlock period.

The study takes advantage of a Florida law requiring people with court-ordered interlocks who repeatedly attempt to start their vehicles after drinking to enter treatment for alcohol use disorder.

Under the law, drivers must enter treatment if they experience three or more interlock violations. An interlock violation is defined as two "lockouts" within four hours. (A lockout occurs when a driver registers a blood alcohol concentration greater than 0.05 percent and is therefore prevented from starting the vehicle.)

Offenders who are referred for treatment must contact a state-certified substance abuse counselor, who develops an individual treatment plan.

The study compared 640 drivers with multiple DUI offenses who were referred to treatment with 806 similar drivers with multiple offenses who experienced one or two interlock violations. The authors looked at the likelihood that the drivers were again arrested for alcohol-impaired driving within one to four years after interlock removal.

The re-arrest rate among the treatment group was 32 percent lower than among the comparison group.

The Florida law doesn't specify a particular type of treatment, and no records about whether a treatment program was successfully completed were available to the authors.

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