Do Ignition Interlocks Really Reduce Drunk Driving?

When a person is caught drinking and driving, part of their punishment may be to install an ignition interlock device (IID) into their vehicle. The goal of these devices is twofold: to stop the individual driver from getting behind the wheel drunk, and to reduce the overall number of drunk driving accidents.

But is it working? Are IIDs actually reducing the number of drunk drivers, and therefore drunk driving accidents? The data largely shows that they are, but there are some caveats.

First things first: what is an ignition interlock device?

According to the Arizona Department of Transportation, “an ignition interlock is a breath-analyzing device that is wired to the vehicle’s ignition and installed on the vehicle dashboard.” If a judge requires you to install an ignition interlock device into your vehicle, you cannot start or drive your vehicle until you breathe into the device. Once you breathe into the device, it analyzes your breath for any alcohol. If there is any alcohol detected on your breath, your vehicle will not cut on. You must also breathe into the device every so often while driving to ensure that you are not drinking while operating the vehicle.

Does the data indicate that ignition interlock devices really reduce drunk driving?

The Centers for Disease Control and Prevention (CDC) states that ignition interlock devices “reduce driving while impaired (DWI) repeat offenses by about 70% while they are installed.” The CDC also mentions that when states have laws requiring all DWI offenders to install an ignition interlock device, this led to a 26 percent reduction in drunk driving being a factor in fatal car collisions from 2001 to 2019. States that have laws that require repeat offenders to install ignition interlock devices had a 20 percent reduction in drunk driving being a factor in fatal car accidents throughout these same years.

A study published in the American Journal of Preventive Medicine showed a 7 percent decrease in fatal drunk driving accidents. The participants of the study analyzed the impact of interlock laws in various states across the country from 1982 to 2013. The researchers found that ignition interlock laws do reduce drunk driving fatal accidents from occurring. Therefore, they urged every state to mandate interlock device requirements for all offenders to save lives.

The Insurance Institute for Highway Safety (IIHS) also chimed in on the effectiveness of ignition interlock devices. They stated that their study shows that if laws require all drunk driving offenders to install these devices, the number of drunk driving-related fatalities decreases by 16 percent.  Therefore, if every state passed these laws, IIHS believes that more than 500 lives would be saved annually.

Lastly, a nonprofit organization called Mothers Against Drunk Driving put together a very informative graph that shows how many drunk driving vehicle starts have been stopped due to ignition interlock devices from 2006 to 2018. According to the graph, over 3 million drunk drivers in the United States have been stopped from starting their vehicles during these years. (Arizona accounted for almost 100,000 of these stopped car starts.)

So yes, the data indicates that IIDs do indeed reduce drunk driving accidents and deaths.

The laws on ignition interlock devices in Arizona

Arizona requires all drunk driving I offenders to install and use ignition interlock devices to earn their driving privileges back. Arizona has taken their ignition interlock device laws to the next level, requiring digital cameras, GPS, and real-time reporting to accompany the devices when installed. This allows users to receive more accurate feedback and take more responsibility to follow the driving rules set in place for them.

The cameras take photos of the driver each time they blow into the device. This is to show that the individual is the correct person who should be blowing into the device and that they are not tampering with the device.

If IIDs work, why are there so many fatal drunk driving crashes?

Drunk driving is a very serious issue in Phoenix and other areas across the country. In fact, the National Highway Traffic Safety Administration (NHTSA) reveals that about 32 people die each day in the United States from a DWI motor vehicle accident. In 2020 alone, almost 12,000 people lost their lives due to intoxicated driving, which was a 14 percent increase from the previous year.

In Arizona, there were almost 300 drunk driving deaths in 2020, and this number rose to over 400 in 2021. That said, over 700 people lost their lives due to intoxicated driving within two short years. As a result, Arizona is ranked as one of the deadliest states for drunk driving in the entire country.

But how can this be, if we require IIDs? How can the number of drunk driving accidents still be so high? Simply put, the devices are not effective if individuals who are convicted of drunk driving are not required to install them – and there are a lot of reasons why those devices don’t get installed. Every state in America has ignition interlock requirements for drunk drivers s, but only about 1/5 of individuals who are arrested for DWIs are required to have interlock devices installed into their vehicles. This could be because:

• The drunk drivers had excellent defense lawyers who were able to suppress evidence or get the charges dropped.
• Some drivers may be eligible for reduced time with the IID, meaning they don’t have to have one installed for the full year.
• Some drivers may not have been ordered to install an IID, as judges do have discretion over such issues.
• Some drivers may have received their DWI/DUI out-of-state, and are not required to install an IID under that state’s laws.
• Some drivers may illegally drive another vehicle even if they are required to have an IID installed.

Perhaps the most likely reason, though, is that IIDs cannot be installed before a person is convicted of a crime, and our court system is still reeling from the pandemic. Maricopa County is moving quickly on the backlog, but it still has a long way to go. As such, there could be drunk drivers out there whose cases simply didn’t move forward for a long time, allowing them to continue putting lives at risk.

Other ways to prevent a drinking and driving accident

You cannot control other people, but you can make sure YOU take the right steps to be safe on the road. If you plan on drinking (or find yourself drinking even though you planned not to). Here are some things you can do to avoid driving and reduce drunk driving accidents:

• Call a family member or loved one to pick you up if you have been drinking.
• If you had a few drinks at a friend’s house, ask to stay the night.
• After drinks with friends or family, use a ride sharing service to get you home safely, such as Lyft or Uber.
• Do not let your friends or family members get behind the wheel after drinking.
• If you notice someone swerving or driving recklessly on the road, call 9-1-1 immediately.

If you or a loved one were injured by a drunk driver, call a Phoenix drunk driving accident lawyer from Plattner Verderame, PC as soon as possible. We will handle all forms of communication with the insurance companies and protect your right to the fair compensation that you deserve for your injuries and losses. To schedule your free case evaluation at our Tempe or Phoenix office, please call one of our offices or fill out our contact form.