What Are Ignition Interlock Devices And How Do They Work?

Posted on: 17 April 2016

If you've been charged with a driving under the influence (DUI) offense, you may be required to have an ignition interlock device installed on your vehicle if you are found guilty. This device allows you to keep your driving privileges (at least for work), while satisfying the court that you won't be drinking and driving. You'll be required to purchase the device and have it installed as well as pay the monthly monitoring fee.

What is an ignition interlock device?

An ignition interlock device (IID) is a breathalyzer machine that attaches to the ignition of your car, truck or van. It requires a person to breathe into a device before starting the vehicle. The device measures the person's blood alcohol concentration and prevents the vehicle from starting if that level is higher than the predetermined level.

In most DUI cases, the level is set at zero, but it may also be set at your state's legal maximum level. If the concentration is less than or equal to the set level, the vehicle may be started as usual. If the level is higher than the programmed limit, the vehicle will not be able to be started for a set period of time. This period is usually increased for every test that is over the limit. Note that this procedure takes a few minutes, so you want to allow extra time to get to work, court and other important appointments.

Once the vehicle is started, the IID will also require additional tests periodically, sometimes called "rolling tests." This is to ensure that a person other than the driver doesn't use the device just to get the car started. In such a test, you have a set period of time to pull over and complete the test or the failure to take the test is logged by the device and a warning to the driver is given. Many devices also begin honking the horn and flashing the lights if a required test isn't taken as requested. This continues until the driver turns off the ignition. 

An IID is one tool used by traffic courts to help offenders stay sober, avoid jail time and still be able to work and meet other approved obligations. A good traffic attorney can help get the court's approval for you to use such a device to help keep your life as normal as possible after a DUI conviction. Contact a business, such as Walsh Fewkes Sterba for more information.