An ignition interlock is a breath analyzing device slightly larger than a cell phone and is wired to the vehicle’s ignition and installed on the vehicle dashboard. Before the vehicle can be started, the driver first must exhale into the device. If the interlock detects alcohol on the breath, the engine will not start.

At random times after the engine has been started, the device will require the driver to provide another breath sample. If the breath sample isn't provided, or the sample exceeds a set blood alcohol level, the device will log the event, warn the driver and then start up an alarm (e.g., lights flashing) until the ignition is turned off, or a clean breath sample has been provided.

For safety reasons, the device can not turn off the car ignition once it has been started.

The International Council on Alcohol, Drugs and Traffic Safety maintains that interlocks, when combined with a comprehensive monitoring and service program, lead to a 40%-95% reduction in the rate of repeat drunk driving offenses among offenders as long as the device remains on the vehicle.

When Arizona Law mandates use of an interlock following a period of driver license suspension/revocation, you must have one installed by an MVD authorized company, and provide us proof of the installation.

We use special forms and procedures to monitor drivers required to have the device installed. We may issue a replacement driver license containing the words “Ignition Interlock” and mark your record so that law enforcement officers will be aware of the interlock requirement if you are stopped.

In cases involving driver license suspension/revocation resulting from a DUI related violation date on or after February 1, 2006, you may be eligible for a special restricted driver license if you have:

• Contacted us to verify eligibility (or have received a notice of eligibility from us)
• No other outstanding withdrawal actions pending on your driving record
• Installed an ignition interlock on your vehicle and provided us proof with a "Verification of Installation" form
• Complied with mandatory alcohol treatment programs (if required) and submitted proof of completion to us
• Submitted proof of future financial responsibility to us (e.g., certificate of automobile liability insurance known as an SR22)
• Paid all applicable fees

A special ignition interlock restricted driver license is valid only during the period of suspension or revocation and allows vehicle operation between the following:

• Place of employment and residence during specified periods of time while at employment
• Place of residence, the person's place of employment and the person's secondary or postsecondary school according to the person's employment or educational schedule
• Place of residence and a treatment or screening facility for scheduled appointments
• Place of residence and the office of the person's probation officer for scheduled appointments
• Place of residence and the office of a physician or other health care professional
• Place of residence and a certified ignition interlock device service facility

Check the list of ignition interlock manufacturers/installers authorized in Arizona.

Call the toll-free number of any of the companies listed and ask about the availability of service in your area and associated costs. You are responsible for installation and monitoring fees.

Once installed in your vehicle, the interlock device must be calibrated and inspected by a certified installer every 30 days for the first three months, then as designated by your certified interlock installer as required.

Drivers who do not comply with interlock requirements are reported to us, and may have the period of time for use extended. In some cases, their driving privilege may be cancelled, suspended or revoked.

In cases involving juveniles who are not statutorily mandated to have an interlock installed but have been ordered by a court to have one, you must maintain the interlock in your vehicle for the duration of the court order. If the device is removed, you will be considered non-compliant and may have your driving privilege cancelled, suspended or revoked.

For answers to the most commonly asked questions about ignition interlocks see our FAQ page.