Jail time, fines and license suspensions are some of the consequences that those convicted of drunken driving face. In some cases, they also face an additional hurdle -- an ignition interlock device that prevents them from committing the same crime twice.
What is an interlock device?
Ignition interlock devices are similar to breathalyzer devices but are attached to a vehicle's ignition. Before starting the car, a driver must breathe into the device, which measures blood alcohol content. If it's above a certain level, the vehicle won't start. The ignition interlock device also may subject drivers to random tests after a certain number of minutes of driving, according to Smart Start Connecticut, a company that sells the devices. If the driver doesn't breathe into the device within a certain window of time, or if his or her blood alcohol content is too high, the vehicle turns off.
Paying the price
Ignition interlock devices aren't cheap. In Florida, for example, convicted drunken drivers will have to shell out almost $1,000 if they're ordered to use a monitoring system for a year: $100 for a refundable deposit, $70 for installation (it must be done by a professional) and $67.50 each month for monitoring and calibration of the system. That's in addition to any fines or court costs.
Unlike other expensive but beneficial auto safety features, ignition interlock devices don't generally bring insurance discounts. In any case, insurers do not officially offer them. Smart Start Connecticut, however, claims on its website an interlock device might help convince insurers to offer you auto insurance after a drunken driving conviction.
State interlock laws
All 50 states allow judges to force certain offenders found guilty of driving under the influence (DUI) to install ignition interlock devices on the vehicles they operate. Fourteen states mandate ignition interlock systems for anyone convicted of a DUI offense, according to the National Conference of State Legislatures (NCSL). Other states may require the devices for anyone under the legal drinking age who's caught driving drunk, for anyone who drives impaired with a child in a car or for anyone whose blood alcohol content exceeds a certain limit.
Do interlock devices work?
Ignition interlock devices are effective, according to the results of a 1999 study conducted by the Insurance Institute for Highway Safety (IIHS). The study found that the risk of committing another alcohol-related traffic violation was reduced by 65 percent for drivers who had installed interlock devices.
But other studies have determined that this change in behavior disappears when the device is removed, according to IIHS. In addition, the system isn't foolproof; a driver can have a non-drinking passenger breathe into the device to start the car or simply borrow someone else's vehicle that isn't fitted with an ignition interlock device. There are legal consequences for such behaviors, but only if the driver gets pulled over.