What is an Ignition Interlock Device?

When a person is convicted of drunk driving, the judge may require the driver to install an ignition interlock device in their vehicle. These devices are designed to prevent DUI, DWI, or OUI offenders from committing another drunk driving offense.

In order for the engine to start, the driver must blow into the device, which computes the driver’s blood alcohol concentration (BAC). If the driver’s BAC is higher than a certain percentage (it can be anywhere from .02 to .04 percent, depending on the state) the vehicle will not start. Once the vehicle has started, the driver will be required to re-submit a breath sample at random times. This is to prevent another driver from blowing into the device, and then the offender driving off in the vehicle while drunk, intoxicated, or impaired.

These devices keep a log of the offender’s breath samples. If the driver fails to provide a sample or has a BAC above the pre-programmed limit, the result will be logged and an alarm will start, which usually involves flashing lights and a honking horn. The only way to stop the alarm is to pull over and turn off the engine until a clean breath sample can be provided.

If you have been arrested for drunk driving, it’s in your best interest to contact an attorney for help. Although ignition interlock devices are annoying, it’s much better to have one installed than have your driver’s license suspended. Sometimes judges are willing to set aside a license suspension if the driver is willing to have a device installed in their vehicle. A DUI attorney will certainly make every effort to help you beat your charges, but if you are ultimately convicted of drunk driving an attorney can negotiate to have an ignition interlock device installed in your vehicle instead of losing your driving privileges.