If you’ve been convicted of driving under the influence (DUI), then one of the penalties may be a requirement to have an ignition interlock device, also known as a breath test device, installed on your car. Whether or not you must get one installed depends on the circumstances of your case and your state. Factors that could require you to have an ignition interlock device installed in your car include having a blood alcohol content (BAC) above a certain amount or having multiple DUIs on your record.
In some states, you can have an ignition interlock device installed to avoid a suspension of your driver’s license. This enables you to continue to drive to work, school or anywhere else you need to go, so you don’t end up inconvenienced like you would with a suspended license.
How does an ignition interlock device work? It’s essentially a breathalyzer installed into your car, and you must provide a breath sample before you can start your car. If the device determines that your BAC is at or above the programmed maximum, which is typically .02, then it interrupts the signal from the starter to your engine, which prevents your car from starting. Depending on the device, you may need to wait for a set amount of time before you can provide another breath sample. If you continue to fail its test, then the amount of time you must wait will be longer after each successive failure. For example, you may need to wait 5 minutes to provide another breath sample after one failure, 15 minutes after the next failure, 45 minutes and then finally 24 hours.
Ignition interlock devices also typically have rolling retests which require you to provide a breath sample while you’re driving. This prevents you from drinking after you’ve gotten your car started, or from having another person provide a breath sample to start your car while you’re intoxicated. If you fail that breath test, the device will create an alarm, which could be flashing your car lights, honking the horn repeatedly, or both. It will do so until you pull over and shut the car off.
The court, DMV or your probation officer can review the logs from your ignition interlock device, depending on which one mandated the installation of the device. Some devices send log information wirelessly, whereas others store logs which can be printed out or downloaded when the device is being calibrated. The cost of installing an ignition interlock device is usually anywhere from $100 to $200, and calibration costs about $60 to $80. Ignition interlock devices may need calibration every 30, 60 or 90 days.
A failure on a rolling retest is a bigger issue than a failure on an initial test, because there are things that can artificially raise your BAC for that initial test. For example, if you recently used a mouthwash with alcohol, that could result in you failing your initial test. On the other hand, if you pass your initial test, there aren’t any valid reasons why you would fail a retest unless you started drinking after or it wasn’t you that took the initial test. If you do have issues on your ignition interlock device’s log, it could result in further penalties.
If you are being charged with a DUI, it’s smart to consult with a defense attorney to go over your options and prepare your defense. Your attorney will be able to explain to you possible circumstances in which you’ll need to install one of these devices in your car. Depending on the strength of the prosecution’s case, your attorney may be able to get your charges reduced through a plea deal for a reckless driving charge, which typically doesn’t result in a suspended license. This will save you the expense and the inconvenience of having an ignition interlock device installed and then calibrated every month.