man blowing on an ignition interlock deviceDriving under the influence of alcohol is a serious offense in New Jersey, and the consequences can be severe. One of the measures implemented by the state to address this issue is the use of Ignition Interlock Devices (IIDs). But what exactly is an IID, and how does it work?

What is an Ignition Interlock Device?

An ignition interlock device is an in-car breathalyzer designed for measuring the amount of alcohol in a driver’s blood by obtaining breath. In New Jersey, the device will prevent the engine from starting if your BAC is at or above 0.05%.

How Does an Ignition Interlock Device Work?

An interlock device is located near the driver’s seat and connected directly to the engine’s ignition system. The small device monitors Breath Alcohol Concentration readings.

It interrupts the signal coming from the vehicle’s ignition to the starter until the driver provides a valid breath sample that has met alcohol guidelines in New Jersey. The driver can start the vehicle as normal if their BAC falls below 0.05%. If the reading is about 0.05%, the ignition will lock out for a one hour waiting period.

Purpose of a Rolling Retest

The ignition interlock device will also randomly ask for continued breath samples after you have started your engine; these are called rolling retests. It is designed to prevent the driver from drinking alcohol after they have started their vehicle. They usually occur every 10 minutes during the operation of the vehicle.

A rolling retest also prevents you from asking someone else to provide a breath sample on your behalf to start the car when you are drunk.

What Will Happen If Someone Fails A Rolling Retest?

If a rolling re-test produces a BAC reading above 0.05% or if a re-test breath sample is not provided within a set interval when prompted, the IID will register a violation and save the incident in its memory. When you return to the interlock vendor for removal of the device, the memory is downloaded and examined. If there are two or more violations in the last 30 days of use, the interlock vendor is prohibited from removing the device. Instead, they issue a certificate to the sentencing court, and you must go before a judge to discuss the violations and additional penalties.

Who Needs an Ignition Interlock Device?

If you were convicted of driving under the influence in NJ, then you will be ordered to install an IID in your vehicle. You’ll also have to get the device installed on your car if you were convicted of refusal to take a Breathalyzer test.


First Offense

0.08-0.09%BAC: Driving privileges are suspended until an ignition interlock device is installed. Once the IID is installed, the driver’s license is immediately restored. The IID must remain on the vehicle for 90 days.

0.10-0.14%BAC: Drivers are obligated to install an IID for between 7 and 12 months. The installation period depends on the severity of the offense and their specific case. Until an IID is installed, the driver’s license is suspended immediately upon conviction, and once the ignition interlock device is installed, the driver’s license is restored.

0.15%BAC or higher: Offenders are required to install an IID for the length of the mandatory 4-6 month driver’s license suspension and for an additional 9-15 months after restoration.

Second Offense

2nd Offenses: Loss of driving privileges for 1 to 2 years, and the required installation of the ignition interlock device during the period of driver’s license loss, and for 2 to 4 years after the driving privileges are restored.

Third Offense

3rd Offenses: Loss of driving privileges for 8 years, and the required IID installation during the period of driver’s license loss, plus 2 to 4 years after the driving privileges are restored.

Drug DWIs

The penalty for the first offense drugged driving includes the mandatory loss of driving privileges for 7 to 12 months, and installation of an IID device. The NJ DWI penalties for second and third offense drug DWIs remain unchanged. However, the new statute is silent on whether IIDs are required for second and third drug DWIs.


First Offense Refusal: Loss of driving privileges immediately upon conviction until an IID is installed. After the IID installation, driving privileges are restored. The IID must remain on the vehicle for 9 to 15 months.

Second Offense Refusal: Loss of driving privileges for 1 to 2 years after an IID installation. The IID must remain on the vehicle during the period of driver’s license suspension and 2 to 4 years after the driving privileges are restored.

Third Offense Refusal: Loss of driving privileges for 8 years, and the IID must remain on the vehicle during this period, plus an additional 2 to 4 years after the driver’s license is restored.

What if a defendant does not own, lease, or principally operate ANY vehicle?

The law requires a defendant who does not own, lease, or operate a motor vehicle to be sentenced differently—and more harshly.

If a defendant falls into this category, his or her privilege to drive in New Jersey is suspended for the length of time he or she would have otherwise been required to install the IID. For example, first offenders with low BAC readings who fall into this category will face a 90-day loss of driving privileges rather than a 90-day IID requirement.

Can I Drive a Rental Vehicle Instead of Getting an Ignition Interlock Device?

You cannot rent a car to avoid using an IID because no rental company will allow you to drive their car with an ignition interlock license. You are also not allowed to drive any vehicle without an IID, even if it is a company car.

It is a 2-part obligation:

  1. You must install one on your car
  2. You cannot drive any vehicle that does not have an IID.

How Long Must Someone Use an Ignition Interlock Device?

If you are a first-time offender, you’ll have to drive with an IID for 3 to 15 months, depending on your breath alcohol level. Much steeper IID penalties apply if you are a subsequent offender.

The law allows the defendant to remove an ignition interlock device from the vehicle after the completion of the required installation period, but only if the defendant obtains a certification from the IID vendor that: 1) during the final month of the installation period, there was a maximum of one failure to take a test with a BAC of 0.05% or more unless a re-test (has to be conducted within 5 minutes after the first test) shows a BAC of less than 0.05%; 2) the defendant complied with all requirements pertaining to the repair, maintenance, monitoring, calibration, and inspection related to the IID.

If two or more test results show a BAC level of 0.08% or higher during the last month of the installation period, the IID vendor will not issue a certification to the defendant. Instead, the IID vendor will forward the violation information to the MVC and the court.

The municipal judge will decide whether to order the issuance of the certification from the IID vendor, allowing removal of the IID or prolonging the ignition interlock device installation up to 3 additional months.

How Often Must I Service an IID?

After an ignition interlock installation, you’ll need to report to the installation center every 60 days to have data downloaded and the interlock device calibrated. You are responsible for making these monitoring appointments with your vendor.

The vendor charges you for installation and each calibration. Failure to comply with the calibration requirement will lead to your IID entering a permanent lock-out. In turn, this will result in additional costs to have the vehicle towed to the vendor and non-compliance with the program.

What Kind of Data Does an IID Record?

In addition to analyzing your breath sample and preventing your engine from starting an IID records and stores data. The important information that an ignition interlock device reports includes:

  • Failure to bring your vehicle in for periodic recalibration
  • Attempts to tamper or remove the device
  • Missed rolling retests
  • Date and time of random tests and startup
  • Results of rolling retest and startup test
  • Your blood alcohol concentration levels for each test

What Are the Consequences of Ignition Interlock Device Violations?

Failing breath alcohol ignition interlock tests is a violation of the laws that cover the use of IIDs. This also applies if you attempt to remove or tamper with the device, refuse to take random retests or fail to return for calibration to the service center. If you violate ignition interlock device rules and regulations, then you will likely face the following:

  • Pay heavy fines
  • Have your restricted driver’s license revoked
  • See your IID installation period extended
  • Have your driver’s license suspended for an extended period

Can I Purchase a Vehicle After Having an IID Installed on My Other Car?

Yes. You can buy an additional vehicle after an IID has been installed on your original car. You must continue to drive only vehicles with IID devices. This may necessitate the installation of an IID on the new car.

What Is the Cost of an IID in New Jersey?

The average cost of an ignition interlock device in New Jersey is approximately $100 per month. The exact amount will depend on the duration you’ll use the device and the vendor you choose.

How Can I Get My Driving Privileges Restored After a DUI in NJ?

After the term of the license suspension period is up, you need to go to NJMVS and apply for your driver’s license to be reinstated. Keep in mind that you’ll have to pay a $200 restoration fee. Your license will remain suspended until you complete the application, pay the required fee, and get another license from the NJ Motor Vehicle Commission.

Criminal defense attorneys can help you navigate a drunk driving offense in New Jersey. With over 34 years of experience, Law Offices of Christopher L. Baxter should be your first, and only, call when arrested for a DUI. Call (856)235-9881 today!