Ignition Interlock Device

Learn more about Ignition interlock devices

You just received a drunk driving offense and are probably overwhelmed and confused as to what the next steps are.

One of the most common requirements following a drunk driving offense is the installation of an ignition interlock device, or car breathalyzer.

This guide will give you all the information you need about what an ignition interlock device is, how it works, what the cost is and more. We’re here to answer all your questions and get you back on the road.

Relax. We’ll take it from here.




What is an ignition interlock device?

An ignition interlock device is a handheld breathalyzer that is installed directly into your vehicle. The devices come in different shapes and sizes but are usually about the size of a television remote.

The first ignition interlock device hit the market in 1988 and after proving to be successful in preventing drunk driving fatalities, their use nationwide has increased each year.

An ignition interlock device is comprised of a few different pieces:

  • Handheld unit
  • Mouthpiece
  • Relay cord connecting the device to your vehicle
  • Camera unit (if required to have by your state)

There are numerous ignition interlock device manufacturers in the United States and each device looks a little different but ultimately, they all have the same components and are roughly the same size.

The handheld fits comfortably in your center console and the relay cord is long enough to allow you to move the device around your front seat, as needed. The camera (if required), is mounted to the front windshield by an official installer.

Now that you’ve had a brief introduction to what an ignition interlock device actually is, let’s dive deeper into how it works.


How does an ignition interlock work?

Ignition interlock devices have two main jobs:

Prevent somebody from starting their car while intoxicated
Guarantee continued sobriety from the driver throughout their time behind the wheel

Let’s look at how the devices work to accomplish each of these goals.

Preventing a driver from starting the vehicle while intoxicated

Anybody with an ignition interlock device installed in their vehicle will be required to provide a breath sample into the mouthpiece of the device before they are able to start their vehicle.

State certified ignition interlock devices use a fuel cell technology to measure the amount of alcohol on the user’s breath. If the breath sample detects alcohol at or above the limit set by the state (usually 0.02), the car will not start.

If the breath sample returns a breath alcohol concentration (BrAC) below that set limit, the driver will be able to insert their key into the ignition and start their vehicle.

Each state has individual ignition interlock device laws and regulations that determine what happens if you provide a failing breath sample.

Some states allow you to try again after waiting a short period of time but may lock you out after so many failed samples. More about lockouts later on in the guide.

Other states allow you to continue blowing into the device until you’ve provided a passing breath sample and can start your car.

Your ignition interlock provider, attorney, court or Motor Vehicle Department can walk you through the requirements in your state so there aren’t any surprises.

Of course, the best way to get through an interlock requirement is to refrain from trying to drive after consuming any alcohol.


You will have 4-6 minutes to complete a random retest

Continuous sobriety while the vehicle is running

Once your vehicle is started, an ignition interlock device will require you to continue providing breath samples throughout the duration of your trip.

Simply put, this ensures that the driver doesn’t just have a sober person start their vehicle for them so they could continue driving after drinking.

These continued tests, often referred to as random retests, are required by your state and all ignition interlock providers must abide by state laws requiring them.

Most ignition interlock providers give the driver 4-6 minutes to complete a retest once prompted. This allows the driver to pull over to the side of the road if needed or take extra precautionary measures if driving in heavy traffic.

Are retests safe?

Retests have proven to be safe and effective at separating drinking from driving and if done safely, can be executed without any issues. Your device will beep when a retest is required. At this time, you’ll simply provide a breath sample into the mouthpiece and can continue driving.

If you provide a breath sample with a BrAC above the limit set by your state, your vehicle will signal you to pull over and turn your car off. As with most things related to ignition interlock devices, the specifics differ by state.

Some states will require your horn to beep or your lights to flash after a failed retest until you turn your vehicle off. In NO situation will the ignition interlock device be able to actually turn your car off, though. Once your vehicle has been started, no ignition interlock device is able to turn it off.

What else might an ignition interlock device be called?

Ignition interlock device is the industry standard term, but like all other products, there are variations around what the mechanism is called. Often the devices are referred to as "car breathalyzers."That makes sense in literal terms as an ignition interlock device is, by definition, a breathalyzer for your vehicle.

You may also see "ignition interlock device" simply abbreviated as "IID." This will often appear on paperwork and court order requiring you to install one of the devices.

If your device isn't being referred to as ignition interlock device, an IID or a car breathalyzer, it may be called a "breath alcohol ignition interlock device" or "BAID". This terminology is primarily used in the state of Illinois but does appear in other states.

There are a number of home grown terms out there describing ignition interlock devices, like "blow 'n' go", but most often, you'll see it referenced as one of the classic names above.


Who needs an ignition interlock?

Since California became the first state to pass an ignition interlock law in 1988, interlocks quickly became established as the most effective way to prevent repeat drunk driving offenses.

License suspensions, the alternate to ignition interlock devices, are difficult to enforce and prove to be ineffective, as three out of four people with suspended licenses continue to drive, according to Mothers Against Drunk Driving (MADD).

Read more about the penalties for driving with a suspended license in your state.

Currently, 30 states, plus Washington D.C., require ignition interlock devices for all drunk driving offenders. States such as West Virginia, Arizona, Louisiana and New Mexico have seen drastic decreases in the number of alcohol related traffic fatalities after implementing all offender ignition interlock laws

All offender states


National organizations, like MADD and National Highway Traffic Safety Administration (NHTSA) publicly support ignition interlock devices and push for their implementation for all drunk driving offenders.

According to MADD, ignition interlock devices have prevented over 2.3 million attempts to start a vehicle while intoxicated. As a result, thousands of lives have been saved because of ignition interlock devices.

Voluntary ignition interlock installation

Most ignition interlock device providers have a voluntary program at a discounted monthly rate. This allows people to install ignition interlock devices as a preventative measure and not only when ordered to as a result of a drunk driving conviction (DUI/OW/OUI/DWI).

Voluntary ignition interlock devices could be helpful in a number of situations:

  • To prevent drunk driving in a teen or young driver
  • To prevent repeat offenses, even if an interlock isn't installed
  • To prevent a first-time offense in a friend or family member
  • To continue with your interlock even after you've fulfilled your required time
  • To guarantee sobriety for drivers of a company vehicle

Read more about voluntary interlocks as drunk driving prevention here.

https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/812425-the- feasibility-of-ignition-interlocks-as-a-prevention-strategies-for-young-drivers.pdf

How do I know if I need an ignition interlock?

The process after receiving a drunk driving conviction, again, is dependent on your state. In most cases, you will receive your interlock requirement through a court order or from the monitoring authority in your state. This could be:

  • Court/Judge
  • Probation Officer
  • Department of Transportation/Motor
  • Vehicles Attorney
  • Call (844) 793-6518 at the start of your DUI process to learn about your requirement.

If required to install an ignition interlock device, you may be eligible to install it right away or you may need to sit out a required license suspension. It’s recommended to call an interlock provider right after your arrest or conviction so you can talk through the full timeline in your state.

In addition to a license suspension, you may be required to complete a number of other steps before you are eligible to install your ignition interlock device, which could include:

  • Alcohol assessment or treatment program
  • Obtaining high risk auto insurance (SR-22 or FR-44)
  • Paying fines and fees
  • Filling out interlock application and other paperwork

Your ignition interlock provider or monitoring authority will be your guide through the process in your state, as each situation is specific to your offense and location.


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Are ignition interlock devices easy to use?

As noted previously in this guide, each ignition interlock device provider has a slightly different device. While the functionality is the same, there will be some variations in how to use and submit breath samples. There are three primary methods of submitting a breath sample:

  • Blow-inhale-blow
  • Straight blow
  • Blow and hum

Let’s take a closer look into the pros and cons of each breath pattern so you have a better idea of what you should look for when choosing an interlock provider.

Blow-inhale-blow breath pattern

The blow-inhale-blow breath pattern is widely accepted as the most accurate and easiest for the user to provide into the device. This pattern requires the user to blow into the mouthpiece for a few seconds, inhale back in and blow into the mouthpiece again.

This should be done in one smooth action without taking your mouth off the mouthpiece. The changes in breath patterns allow the device to accurately read a BrAC without requiring extreme force behind your breath sample, like you would need to provide with straight blow ignition interlock device.



Inhale 2 SECONDS

Inhale 2 SECONDS



Straight blow breath pattern

The straight blow breath pattern requires the user to blow into the device with one single, powerful breath, for a period of time. Many people have a hard time providing a strong and long enough breath sample for this to be an effective way to activate the device.

In addition, many states choose to exclude straight blow devices from their list of certified providers because they aren’t as reliable and effective as blow-inhale-blow devices.

Blow and hum breath pattern

A blow and hum breath pattern is the toughest to master. It requires the user to submit a breath sample by blowing and humming into the mouthpiece. The exact technique is hard to master and many customers face unnecessary lockouts because of the difficult hum requirement.

Ignition interlock device handheld buttons

Most ignition interlock devices resemble mainly the same shape but their interface and buttons on the handheld range from simple to complex.

The simplest interface has only one button to activate which helps to reduce the chance of error. In addition, this makes providing a random retest quick and easy to execute without having to look at the device.

One button devices are the easiest to use!

Some more complicated interfaces feature a full key pad and advanced options to customize the look of the LED screen on the device. Use caution when choosing these devices - the extra bells and whistles don't add to the performance of the device and in most cases, complicate the process.


How do I install an ignition interlock?

Ignition interlock devices are always installed by state-certified installers. Each certified ignition interlock provider has approved installers in the state they work with through the installation, calibration and removal process.

It’s important to locate an ignition interlock provider with many locations, as that will ensure your ignition interlock process is quick and convenient. You will return to your service center multiple times throughout your ignition interlock lease.

Ignition interlock device installation

The initial installation appointment is set up for you by your ignition interlock provider. The representative will work with you to locate an installer convenient for you.

At your installation appointment, you can choose to wait on location for the installer to complete the work or you can leave and come back later in the day. Depending on the complexity of your vehicle, installations could take anywhere from 30 minutes to a few hours.

Your installer will be available to train you on how to use your device and can help answer any questions you may have.

State-required calibrations and service appointments

All states require ignition interlock devices to be calibrated on a regular basis, usually every 30 to 60 days. Ask your interlock provider what the exact calibration requirements are for your state.

You will be required to return to your installation location on or before the day your calibration is due. The installer will put your device on a calibration station that will ensure it is still measuring alcohol levels accurately.

Some states require the installer to inspect the device for signs of tampering at all calibration appointments.

How do I get my device removed?

Once you are eligible to remove your device, you'll have the option to extend your lease to a voluntary lease at a discounted price or return to your installation location to have your device taken out of your vehicle.

It's important to confirm that you are eligible to remove your device with your monitoring authority before scheduling your appointment.

At your de-installation appointment, your installer will remove the device and will send all pieces back to the interlock provider. They may provide you with paperwork confirming the removal, if your state requires it.


Intoxalock has over 3,500 installation locations nationwide

How do I know which interlock providers are available in my state?

Each state has an individual process for certifying ignition interlock device providers. Some states require certain technology or service center coverage in order for a provider to do business in that state.

In addition to the initial certification, states require certified ignition interlock vendors to continue to meet certain standards while doing business in their state.

Many smaller (and some Larger) interlock vendors are regularly suspended and decertified in states as they are able to get

through the certification process but are unable to maintain requirements set to do business.

Intoxalock is certified in 46 states and unlike many other providers, has never been decertified from a state because of compliance issues.


How much does an ignition interlock cost?

Because they are only needed for a temporary period of time, ignition interlock devices are leased from the manufacturer, not purchased outright. With this model, you’ll pay a monthly “rental” fee and will return the device at the end of your lease.

Ignition interlock devices cost, on average, between $60 and $90 a month. There are many factors that contribute to the overall price of your ignition interlock device, including:

  • The type of vehicle you’re installing your device in
  • The state requiring your installation
  • Any additional features you may be required to have (camera, GPS, wireless reporting)
  • Length of time you are required to have the interlock

Ignition interlock cost

What is the cheapest ignition interlock device?

Most ignition interlock devices cost close to the same amount, at the end of the day, despite how manufacturers position the pricing. Instead of looking directly at the monthly price, look for the best value interlock and choose a company with many locations, a clean history free of state suspensions, knowledgeable representatives and devices that exceed industry standards.

You’ll likely have some additional fees that could be built into your overall price or charged separately for your installation, calibrations and removal.

If you’re still reading, you should be very comfortable with what ignition interlocks are, who needs them and how they work. Now, let’s dig deeper into the growth behind the use of interlocks across the country and their effectiveness.


How effective are ignition interlocks?

Since California became the first state to pass an ignition interlock law in 1988, interlocks quickly became established as the most effective way to prevent repeat drunk driving offenses.

License suspensions, the alternate to ignition interlock devices, are difficult to enforce and prove to be ineffective, as three out of four people with suspended licenses continue to drive, according to Mothers Against Drunk Driving (MADD).

Read more about the penalties for driving with a suspended license in your state.

Currently, 34 states, plus Washington D.C., require ignition interlock devices for all drunk driving offenders. States such as West Virginia, Arizona, Louisiana and New Mexico have seen drastic decreases in the number of alcohol related traffic fatalities after implementing all offender ignition interlock laws


74% Reduction:

Of repeat offenses when ignition interlocks are installed.

Source: California DMV


7% Decrease:

Of fatal crashes with mandatory interlock laws.



Every 90 Seconds:

A person is injured in a drunk driving crash.


National organizations, like MADD and National Highway Traffic Safety Administration (NHTSA) publically support ignition interlock devices and push for their implementation for all drunk driving offenders.

According to MADD, ignition interlock devices have prevented over 2.3 million attempts to start a vehicle while intoxicated. As a result, thousands of lives have been saved because of ignition interlock devices.


How can I avoid false positives?

Ignition interlock devices are designed to accurately measure alcohol. Any alcohol. Because of this, it’s important to be mindful of what products contain alcohol in trace amounts and avoid exposing them to your ignition interlock device.

Most states will hold you accountable for any breath tests that result in alcohol readings, which can seem overwhelming. With a few easy lifestyle changes, it’s easy to keep your ignition interlock breath samples clean and free from alcohol.

Products containing alcohol

Household products like mouthwash, some lotions and cleaners can include alcohol. Simply refrain from using those when you are going to be in close contact with your interlock. There are alternative options on the market for you to switch out use for.

Clean breath samples

It’s always recommended to only drink water or thoroughly rinse your mouth with water before providing a start-up sample or a random retest to ensure you are providing a straight, clean breath sample, every single time.

Can I beat an ignition interlock device?

While it may sound tempting, ignition interlock devices have evolved tremendously over the years and are virtually impossible to cheat, circumvent or trick now. In addition, states have adopted strict penalties for any attempts at cheating your interlocks.

Most ignition interlock devices have mechanisms in place to catch potential attempts of tampering and are usually reported at your monthly or bi-monthly required calibration/ inspection appointment.

Ignition interlock device breath patterns are set up in a way that make them unable to replicate with anything beyond a human breath sample. In addition, attempts of tampering could permanently damage your device, leaving you with hundreds to thousands of dollars in replacement fees.

Our advice? Don't do it.


What is a lockout and how can I avoid them?

If your device goes into a lockout, you will be unable to submit a breath sample to start your vehicle until the lockout is cleared. There are many reasons you could enter into a lockout but all of them are avoidable with proper maintenance and use of your interlock.

Missed calibration appointments

One of the most frequent ways people end up in a lockout is by missing their state-required calibration appointment. If your device isn’t calibrated on time, you aren’t in compliance with your state regulations and your device will lock out.

It’s important to pay attention to prompts from your interlock provider that your lockout is coming up. Your device will display a countdown as your calibration nears. Complete your calibration before the countdown expires to avoid a lockout.

Providing too many failing breath samples

Depending on your state’s regulations and laws, too many failed breath samples in a set period of time could result in a lockout. Make sure to ask your Intoxalock representative to explain the rules for your state so you understand how to avoid a lockout.


How to choose an ignition interlock provider?

When looking at different ignition interlock providers, there are many factors to keep in mind. You want to make sure your entire process is smooth from start to finish, and choosing an established and reliable provider will be your key.

How many locations do they have?

An interlock provider with a high number of locations across the country will be most likely to find one close to you. In addition, a high number of certified locations shows they are a leader and trusted in the industry. Intoxalock has more locations than any other ignition interlock provider in the United States.

How many years have they been in business?

Ignition interlock devices are complicated to manufacture and regulate. Beware of newer companies in the market who have only been in business a few years. They are more likely to have issues with their technology and may not be knowledgeable in all ignition interlock regulations.

How easy is the device to use?

Look for an ignition interlock provider, like Intoxalock, with a simple blow-inhale-blow device and only one button to activate on the handheld.

Look into any decertifications or suspensions from a state.

Very few ignition interlock providers have never been decertified or suspended from a state due to compliance violations. If you choose a provider with a history of suspensions, you risk having to pay extra to switch providers part way through your lease.

Pick an interlock provider with knowledge of state regulations.

Ignition interlock devices are a crucial part of the DUI process and should not be handled by any company as a quick, hard sale. Your interlock provider should go the extra step to answer questions about your state’s laws and processes. Intoxalock has state specialists thoroughly trained to help walk you through, step by step.


What I can expect from intoxalock?

We know this isn’t a fun call to make. Many of our representatives have been exactly where you are today. They’ve experienced all the emotions and stress of a drunk driving offense and are ready to help you through the process.

We understand.

When you call in, you’ll speak to our caring interlock specialists. They won’t pass judgement and they will be there to guide you every step of the way. Intoxalock has a near perfect rating on TrustPilot and is dedicated to maintaining that as a standard.

Read some of our real customer reviews.

We'll answer your questions.

When you call, we will gather information and walk you through the process as quickly as we can. If you want to stay on the phone and talk through additional details, our team is more than happy to do that. At the end of the call, we will schedule your installation for you at a location convenient for you and will have everything set up for your next steps.

We'll schedule your installation.

We will start the call by asking for some basic information such as your name, address, type of offense and vehicle information. From there, we can help you fill in the rest. We will let you know what documents are needed from your state and can walk you through the steps to get them.

Once your installation is scheduled at a location and time convenient for you, we will explain how to use the device and can answer any questions you might have.

We're here for you.

The call is quick and will get you much closer to regaining driving privileges. We are your partner through the process. Call today and let’s walk through it together. Relax. We’ll take it from here.

Contact us

Contact us today to get back on the road with your ignition interlock device. The call will only take a few minutes and our state representatives will make sure you have everything you need to get through the process.

Call (844) 793-6518 or visit www.Intoxalock.com