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Ignition Interlock Devices: In-Car Breathalyzer Requirements

Ignition interlock devices (IIDs) prevent you from operating a vehicle when the device finds alcohol on your breath. These devices often get installed on the cars of those convicted of driving under the influence (DUI). They're essentially Breathalyzer machines that control the ability to start your vehicle. Almost all states have drunk driving laws allowing or requiring judges to order ignition interlock devices in cars operated by certain drunken driving offenders.

State laws vary when it comes to the ignition interlock requirement. Consult specific state drunk driving laws to determine whether an ignition interlock is mandatory or within the judge's discretion in any given case.

This article discusses how IIDs work. It also addresses discretionary versus mandatory IID laws. Finally, the article discusses the installation and costs associated with IIDs.

How an Ignition Interlock Device Works

An ignition interlock device works by measuring your blood alcohol concentration (BAC) and turning off your motor vehicle's ignition if your breath contains alcohol. Most IIDs use a lock-out period to prevent you from starting your car if the device detects any amount of alcohol in your breath sample. The lock-out period typically gets longer with each failed test.

During rolling retests, most IIDs signal to do a fresh breath test. If the machine doesn't confirm clean breath within a specific period of time, an alarm will sound, or the car's horn will honk to prompt you to turn off your vehicle. IIDs don't turn off a moving car in case of a failed retest. Depending on the system in place, the device may save information relating to the failed retest.

Any tampering with an IID usually results in revocation of driving privileges. This behavior may also lead to other criminal charges.

Discretionary Ignition Interlock Device Laws

State laws often give judges the discretion to order an ignition interlock device for specific classes of convicted drunken drivers, such as first-time offenders. Under ignition interlock laws of many states, IIDs may be used for part of an offender's license suspension period.

It's common for courts to require the installation of an IID as a condition of obtaining a restricted license. The goal is to prevent driving under the influence of alcohol.

In these situations, qualifying offenders usually have to meet other sentencing requirements to be able to drive with an IID. These requirements can include:

  • Jail time
  • Probation
  • Payment of a fine
  • Completion of an alcohol treatment program
  • A period of full license suspension

Mandatory Ignition Interlock Device Laws

A growing number of states make an ignition interlock system mandatory in certain types of drunk driving cases. That means the ignition interlock rule isn't at the judge's discretion in issuing a court order.

Some states or specific cases may opt for the SCRAM device instead. A SCRAM device also monitors alcohol consumption in general. Some states have begun requiring first-time DUI offenders to have IIDs installed. The most common situations in which these states require an IID include:

  • Having multiple drunk driving convictions
  • Having a minor in the car at the time of the incident
  • Having an elevated blood alcohol content level

Ignition Interlock Device Installation and Costs

States have rules about installing and inspecting ignition interlock devices. Generally, drivers must have the device installed by a state-approved service center and show proof of installation to the court. Often, state law also requires periodic device inspections by an approved installer.

Generally, the offender must pay any fees associated with an IID. These can include:

  • Fees for the device itself
  • An installation fee
  • Monitoring or calibrating fees
  • A security deposit or device insurance fee

Some states reduce certain drunk driving fines for those offenders who show an inability to pay the costs of an IID.

Get Help With Your DWI or DUI Offense From an Experienced Attorney

If you believe you're a good candidate for an ignition interlock device following a DUI conviction, consider speaking with a local DUI attorney today. Installing an IID device might be an alternative to losing your driver's license or driving privileges. Whether you're facing a first offense or repeat DUI, an attorney can help determine whether you're eligible for an ignition interlock program.

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