Drunk driving is one of the top public safety threats in Arizona and around the United States. According to the most recent data published by the Arizona Governor's Office of Highway Safety, more than 270 people were killed in DUI car accidents in the state in 2017 alone. Many more were injured in drunk driving accidents.

In an effort to reduce intoxicated driving, state and federal policymakers have pushed a wide range of different initiatives and solutions. Among other things, DUI offenders are frequently required to install interlock ignition devices (IIDs) on their vehicles. As noted by the National Conference of State Legislatures (NCSL), Arizona is one of 28 states that mandate the installation of an interlock ignition device for every drunk driving offense.

What is an Interlock Ignition Device?

An interlock ignition device is handheld breathalyzer that is installed directly into a motor vehicle. Though these devices come in many different forms, they are usually about the size of your average television remote—with the device itself being attached to a mouthpiece.

When properly installed, an interlock ignition requires the driver to provide a breath sample—by blowing into the mouthpiece—before the vehicle can be started and put into gear. If the breath sample is clean, the car will start as normal. However, if the breath sample indicates a blood alcohol concentration (BAC) level that is above the approved limit (usually an IID is set at just 0.02), then the interlock ignition device will not allow the car to start.

Research: Ignition Interlock Devices Help to Reduce Drunk Driving

With support from the National Highway Traffic Safety Administration (NHTSA) and on behalf of policymakers and judges, the National Center for State Courts has put together a comprehensive assessment of the effectiveness of ignition interlock devices. Among other things, the researchers reviewed more than a dozen individual studies and compared the IID requirements in all 50 U.S states. Here are three of the most important things that the researchers from the National Center for State courts found:

1. Most drivers do indeed comply with their state's interlock ignition requirements. Research conducted by the state of Michigan found a rate of compliance of nearly 97 percent.
2. A 2015 study that reviewed more than two dozen states found a significant correlation between ignition interlock device standards and reduced overall drunk driving fatalities.
3. IIDs are most effective when used in conjunction with other treatment options. A 2016 study found that drivers convicted of DUIs had a 32% lower recidivism rate after receiving intensive alcohol-use disorder (AUD) treatment along with an interlock device.

An Overview of Arizona's Interlock Ignition Requirements

Arizona has some of the most strict interlock ignition rules in the entire county. Under Arizona law (A.R.S. § 28-3319), every driver convicted of a DUI offense—including those convicted of first-time offense—must have a state-certified interlock ignition device installed in their vehicle for at least twelve months. Though, first time DUI offenders who were not involved in an accident may be eligible to get their interlock ignition device removed after six months if certain requirements are satisfied.