Will an interlock breathalyzer earn me an insurance discount?

Amy Higgins

A drunken driving conviction brings expensive penalties, including court fees, fines and high-risk auto insurance. Many states even require those found guilty of driving under the influence (DUI) or driving while intoxicated (DWI) to have interlock breathalyzers installed in their vehicles. But could those who are not required to do so benefit if they install one by choice?

Insurance discounts?

Insurance poses a significant cost for DWI offenders. According to the National Highway Traffic Safety Administration, the eagerness of offenders to sign up for Quebec's interlock device program may stem from the fact that Quebec's provincial government subsidizes the cost of insurance.

But is it possible to get a reduced insurance premium in the United States? So far, such discounts are not widespread.

According to interlock device company Smart Start, installing an ignition interlock breathalyzer when you're not legally required to could demonstrate to auto insurance companies that you are more responsible and therefore less risky to insure. Sens-O-Lock, distributor of the Determinator ignition interlock device, says that insurance companies are looking at its product and that it expects discounts will be offered in the future.

How interlock breathalyzers work

Ignition interlock devices are relatively small. When installed, they are wired to a vehicle's electrical system, which controls the driver's ability to start the vehicle. In other words, the driver must pass a breathalyzer test to turn on the car.

The Determinator ignition interlock device, for instance, uses a voice prompt that lets the driver know he's required to give a breath test. The driver has about 60 seconds to provide a deep-lung breath sample. The Determinator then tests the sample and lets the driver know whether the vehicle will start.

A driver then is given two random rolling retests within 20 minutes after starting the vehicle to ensure another person did not provide the original breath sample. If the driver fails the retest, he is instructed to pull over and shut off the car. Failing to do so will make the vehicle's horn sound and the lights blink until the engine is shut off. Ignition interlock devices assigned to offenders record the data for court officials.

According to the National Highway Traffic Safety Administration, interlock fees for drunken driving offenders range from $65 to $90 a month in most states, not including installation fees. Some companies also charge the driver every time information is downloaded from the device. Those who are not required by law to have an ignition interlock device still can buy one. For instance, the Determinator costs $1,595, plus taxes, shipping and installation for non-offenders.

Preventing relapses

Offenders with interlock devices may be more likely to steer clear of further drunken driving offenses. After two systematic reviews of 13 studies, the Task Force on Community Preventive Services concluded that re-arrest rates decreased by a median of 67 percent when interlocks were installed. Alabama, South Dakota and Vermont are the only three states without interlock laws for DUI offenders, according to the Insurance Institute for Highway Safety.

According to Sens-O-Lock, drivers who rarely consume alcohol might benefit from ignition interlock devices because they can prevent the tragic consequences of unplanned overindulgence.

Although studies suggest that interlock devices are effective, they can have glitches. According to Sens-O-Lock, some foods may give off a low alcohol reading, and some prescription drugs can interfere with breathalyzer test results. That being said, it's a good idea to weigh the pros and cons before installing an ignition interlock device in your vehicle by choice.

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