Ignition Interlock Devices (IIDs) in DUI Cases

How ignition interlock devices work, when IIDs are required, and the costs of IIDs for drivers.

To help combat drunk driving and DUI recidivism, many states require the use of ignition interlock devices (IIDs) for those convicted of crimes involving alcohol (and sometimes drugs). Often called a "car breathalyzer," an ignition interlock device installed in a vehicle prevents persons who have recently consumed alcohol from operating the vehicle. This article explains how an IID works, when someone might be required to install an IID, and how much IIDs typically cost.

What Is an Ignition Interlock Device and How Does It Work?

An IID is just a breathalyzer that's connected to the car's ignition system. Specifically, an IID is a small machine mounted inside a vehicle that's linked to the car's ignition. The device has a small tube attached for the driver to provide a breath sample. When the driver breathes into the tube, the IID analyzes the breath sample and determines the driver's breath alcohol concentration. If the IID detects alcohol, the car won't start. And the car's ignition won't operate until the driver provides a breath sample free of alcohol particles.

IIDs are also equipped with an electronic monitoring system. So when drivers test positive for alcohol, the results are recorded. The monitoring company will then notify the court or probation officer that the driver tested positive for alcohol.

Some IIDs also require additional breath samples, called "rolling" samples or tests, even after the vehicle is running. IIDs that require rolling samples will periodically give an auditory signal indicating another sample is required. The driver then must pull over and provide a breath sample within a certain period of time (normally, a few minutes or so). When alcohol is detected on a rolling sample, it won't typically shut off the car, but the IID records the information and the court or driver's probation officer will likely receive notice of the failed test.

How Much Do Ignition Interlock Devices Cost?

Drivers who are required to use an IID don't have to buy the machine. IIDs are only available via leasing and must be serviced by certified dealers. The dealer usually charges $50 to $150 to install the IID and an additional $50 to $100 per month for leasing. Dealers also charge a similar fee for removing the IID.

In the end, an ignition lock device might cost the driver somewhere in the ballpark of $500 to $1,000 or more. It just depends on how long the driver is required to have the IID. As discussed below, depending on the circumstances, the duration of IID requirements can range from a few months to a number of years.

What Types of Convictions Lead to Ignition Interlock Requirements?

The purpose of ignition interlock devices is to prevent impaired driving. So IIDs are generally required only for driving offenses involving drugs or alcohol.

IID requirements for DUI convictions. A DUI conviction is the most common reason a driver would have to install an IID. Generally, a DUI conviction will lead to license suspension for some period of time. In many states, the driver will have to install an IID following the suspension period. Typically, the IID requirement duration increases if the driver has prior DUI convictions or the current offense involved aggravating factors such as a high blood alcohol concentration (BAC).

IID conditions for other alcohol-related offenses. In a few states, judges can order IIDs for offenses other than DUIs. In Washington, for instance, a reckless driving charge requires the installation of an IID if the offender had any amount of alcohol in his or her system. And, in Kansas, minors who are caught driving after consuming alcohol can be ordered by the judge to install an ignition interlock device.

Administrative license-related penalties. Implied consent laws require all drivers lawfully arrested for a DUI offense to submit to chemical testing (usually, of the blood or breath) when asked to do so by an officer. The officer sends the results of the chemical test to the state's department of motor vehicles (DMV). The DMV will normally administratively suspend the license of any driver who fails (with a BAC of .08% or more) or unlawfully refuses a test. An administrative suspension isn't dependent on a conviction in criminal court. However, as with a suspension resulting from a conviction, many states impose an IID requirement following the completion of an administrative suspension period. The duration of the IID requirement generally depends on the circumstances of the current offense and the driver's history. For example, an unlawful refusal typically leads to a longer IID requirement than a failed test. And repeat offenders are normally looking at a longer IID requirement than first offenders.

IIDs as conditions of alternative sentencing programs. Drivers facing impaired driving charges are sometimes eligible for rehabilitative alternative sentencing programs. These programs often reduce or eliminate criminal penalties like jail and instead require the driver to participate in treatment and abide by other conditions aimed at maintaining sobriety. Generally, IIDs are a condition of these types of programs.

Hardship licenses requiring an IID. It's also common for IIDs to be a requirement for obtaining a hardship license. Many states offer hardship licenses to drivers suspended for DUI, which affords limited driving privileges during the suspension period. Normally, drivers must provide proof of installing an IID as part of the application for a hardship license.

What Are the Penalties for IID Test Failures and Violations?

A driver can get in trouble for providing an IID breath sample that's positive for alcohol, tampering with an IID, or attempting to circumvent the IID by getting someone else to provide an alcohol-free sample. The penalties for these types of violations depend on the circumstances but might include:

  • Probation violations. For a driver ordered by the court to install an IID as a condition of probation, a test failure could be grounds for probation revocation. Revocation of probation often means jail time.
  • Criminal charges. Tampering with an IID is a misdemeanor in most states and can carry up to one year in jail and up to $1,000 in fines.
  • Termination from alternative programs. IID violations can be grounds for termination from alternative sentencing programs. Drivers who are terminated from one of these programs generally face the original criminal charges and associated penalties.
  • Loss of hardship license. Drivers with hardship licenses will typically lose their hardship privileges for IID violations.
  • Extension of IID requirement period. Finally, IID violations will generally extend the IID restriction time—generally, for 30 to 60 days.

In many states, it's not just the driver who can get in trouble for IID violations. Anyone who assists the driver to circumvent an IID by providing a breath sample could also face criminal charges.

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