Ignition Interlock Device Requirements in New Jersey

If you are convicted of DWI in New Jersey, you will almost certainly need an ignition interlock device. The December 2019 law reform made interlock the centerpiece of New Jersey's DWI penalty structure. Understanding how it works, what it costs, and what happens if you violate the rules is essential.

Papa Alpha & Alpha Law Firm in Springfield, NJ helps clients navigate interlock requirements as part of our DWI defense practice. We also fight to keep you from needing one in the first place.

What Is an Ignition Interlock Device?

An ignition interlock device (IID) is a breathalyzer installed in your vehicle. Before you can start the engine, you must blow into the device. If the device detects alcohol at or above 0.05% BAC, the vehicle will not start.

The device also requires rolling retests at random intervals while you are driving. If you fail a retest, the device logs the violation and triggers an alarm — horn honking and lights flashing — until you pull over and turn off the engine.

Every interlock device records all test results, including passes, fails, and missed tests. This data is transmitted to the MVC and monitored by the interlock provider.

Interlock Duration by Offense Level

New Jersey law sets specific interlock periods based on your offense and BAC level.

First Offense — BAC 0.08% to 0.09%

• Interlock required during license suspension period
• Interlock continues for 3 months after license restoration

First Offense — BAC 0.10% or Higher

• Interlock required during license suspension period
• Interlock continues for 7 to 12 months after license restoration

Second Offense

• Interlock required for 2 to 4 years after license restoration

Third Offense

• Interlock required after license restoration (court determines duration)

Refusal Cases

• First refusal: Interlock for 9 to 15 months after restoration
• Second refusal: Interlock for 2 to 4 years after restoration

How to Get the Device Installed

After your DWI conviction, the court order will specify your interlock requirement. You must have the device installed by a state-approved provider before your license can be restored.

Approved providers in New Jersey include:

• Draeger
• Smart Start
• Intoxalock
• LifeSafer

The installation process takes about an hour. The technician wires the device into your vehicle's ignition system. They will train you on how to use the device properly.

You must install an interlock on every vehicle registered in your name or that you regularly operate. If you do not own a vehicle, you must file a declaration with the MVC stating that you will not drive any vehicle without an interlock.

Costs

Interlock devices are not cheap. Here is what to budget:

| Cost | Amount | |------|--------| | Installation | $100 – $200 | | Monthly lease/monitoring | $50 – $100 | | Calibration (every 30–60 days) | Included in monthly fee or $25 – $50 | | Removal | $50 – $100 | | Violation reset fee | $50 – $75 per incident |

Over a 12-month interlock period, expect total costs of $800 to $1,500. For multi-year requirements, costs can exceed $3,000 to $5,000.

New Jersey does offer a financial assistance program for those who cannot afford the interlock. You can apply through the MVC for a reduced-fee program based on income eligibility.

Rules You Must Follow

The interlock requirement comes with strict rules. Violating them can extend your interlock period or result in additional penalties.

Do Not Attempt to Tamper

Tampering with, disconnecting, or bypassing the interlock device is a separate offense under N.J.S.A. 39:4-50.19. Penalties include fines and extension of the interlock period. The devices have anti-tampering features and log any attempts.

Do Not Miss Calibration Appointments

Your device must be calibrated on a regular schedule — usually every 30 to 60 days. Missing a calibration appointment triggers a violation. Set reminders. Do not miss these appointments.

Do Not Fail a Test

A failed breath test is logged and reported. Multiple failures can trigger a lockout that requires a service visit. The MVC reviews violations and can extend your interlock period.

Do Not Drive Without the Interlock

If you are caught driving a vehicle without an interlock while under an interlock order, you face additional penalties including fines and license revocation extension.

Do Not Have Someone Else Blow

Having another person provide the breath sample is illegal. Interlock devices include a camera that photographs the person providing the sample. This footage is reviewed during calibration visits.

What Triggers a Violation?

The most common interlock violations include:

• BAC reading above 0.05%: The device will not start your vehicle. This is logged as a fail.
• Missed rolling retest: If you do not provide a sample when prompted while driving, it is logged as a violation.
• Failed rolling retest: If you blow above the threshold during a retest, the device records the violation and triggers the alarm.
• Missed calibration: Failing to bring the device in for scheduled maintenance.
• Power disconnect: If the device loses power (battery disconnected), it logs the event as a potential tamper.

Not all violations mean you consumed alcohol. Mouthwash, certain foods, and medications can cause false readings. If this happens, wait a few minutes and retest. The device allows retests after a short waiting period.

What Happens After the Interlock Period?

When your interlock period ends, you must have the device professionally removed by the same approved provider. They will download the final data report and submit it to the MVC.

If you completed the interlock period without significant violations, the MVC will update your license status. If you had violations, the MVC may extend the interlock period.

After removal, you can drive normally without restriction.

We Can Help

Whether you are trying to avoid an interlock requirement by fighting your DWI charge or need guidance navigating the interlock process after conviction, Papa Alpha & Alpha Law Firm is here for you.

Call us at (201) 555-0100 for your free consultation. We serve clients in Springfield, Union County, and throughout New Jersey.