What Is An Ignition Interlock Device ?

What is an ignition interlock device (IID)?

An ignition interlock device is a small device that’s installed in a vehicle that prevents the vehicle from starting if the driver’s breath sample was not provided or if the driver’s breath alcohol content (BrAC) is above a preset amount, usually .02 g/dl. IIDs can sometimes conduct rolling tests that require additional breath samples during the drive to ensure that the driver’s BrAC remains below the preset amount.

Most states require all DUI offenders to install an IID on a vehicle they own or operate.

Failing an Ignition Interlock Device Test

If you fail the initial IID test, the IID will prevent your car from starting. You can retest after a short amount of time.

While driving, the IID will alert you to notify you that a rolling retest is needed and you usually about about 5 minutes to provide a breath sample. If you fail to provide your breath sample or if your BrAC is above the preset limit, the IID will trigger an alarm such as flashing your car’s lights and sounding the horn until you can pull over and turn off your car.

Failed tests are recorded by the IID and are typically reported to monitoring agencies such as the court, DMV, or your probation officer.

How Much Does an Ignition Interlock Cost?

The total cost for IIDs can vary by state, provider, and extra features that’s needed. IID installations can vary between $70-$300, monthly leasing fees are usually between $60-$150, and calibration fees can vary from $25-$100.