Attorney at Law

Ignition Interlock Devices: A Deeper Look

March 23, 2023

Installation of an ignition interlock device may be one of many penalties issued by a court for driving under the influence of alcohol or drugs (DUI). Often, if an ignition interlock device is part of a DUI conviction, the defendant is responsible for installation costs. But what are ignition interlock devices? And why are courts issuing them to DUI defendants?

An ignition interlock device is a small, handheld breathalyzer approximately the size of a remote control. It typically consists of a mouthpiece, unit, relay cord, and sometimes a camera. 

The purpose of an ignition interlock device is to prevent the driver from turning on their car if they are under the influence of alcohol. These devices accomplish this by preventing the car’s ignition from activating unless the ignition interlock device is deactivated. There are three general types of ignition interlock devices: blow-inhale-blow, straight blow, and blow and hum.

The blow and hum ignition interlock device requires the user to blow into it and hum for a certain period of time before deactivating. The straight blow requires a forceful expulsion of breath in order to trigger the device. Finally, the blow-inhale-blow system requires the user to exhale, inhale, and exhale again before deactivating. 

If any of these devices detect alcohol, typically equivalent to a 0.02% BAC or a single drink, then the device will lock the user out of starting their vehicle. These lockouts are typically temporary for 30 minutes but some states also allow conditions to be imposed for a permanent lockout. 

If a defendant required to use an ignition interlock device chooses to ignore the court’s order, things get considerably worse. Failing to use an ignition interlock device can take several forms including:

  • Removing the device
  • Not installing the device on all vehicles the defendant uses
  • Borrowing a friend’s vehicle to avoid the device
  • Never installing the device in the first instance

All of these are considered very poor moves. While they may temporarily create some convenience, the penalties for failing to obey a court order quickly outweigh any temporary benefit. Defendants can be fined thousands of dollars, receive even longer suspension of driving privileges, have your vehicle impounded, receive a felony charge, or be imprisoned. Additionally, because installation of an ignition interlock device is a court order, failing to obey it, whether intentional or not, may also qualify as contempt of court and result in a contempt charge.

The best way to avoid complications and difficulty with an ignition interlock device is to avoid a DUI conviction in the first place. If you have been charged with a DUI or if you would like to appeal the requirement for an ignition interlock device, contact an attorney who can help you explore your options and advocate zealously on your behalf. 

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