DWI: BAC 0.08 Threshold, Penalties by Offense Tier, Refusal, and Ignition Interlock (39:4-50)

DWI in New Jersey — N.J.S.A. 39:4-50

New Jersey's driving while intoxicated statute, N.J.S.A. 39:4-50, is one of the most heavily tested Title 39 provisions on the LEE because it layers a per se BAC rule, tiered penalties, a separate refusal offense, and mandatory ignition interlock. Officers must know these figures cold — not the approximate ranges, but the exact dollar bands, suspension lengths, and interlock periods the Legislature has fixed.

BAC Thresholds

The statute creates three distinct BAC thresholds depending on who is operating the vehicle:

A driver is also guilty of DWI when under the influence of intoxicating liquor, narcotics, hallucinogens, or habit-producing drugs even with a BAC below 0.08% — the impairment prong does not require a chemical number. Drug-impaired cases are charged under this impairment theory because there is no per se drug threshold.

First-Offense Penalties (Tiered by BAC)

The 2019 reform (P.L. 2019, c. 301) replaced long hard suspensions with mandatory ignition interlock for most first offenders. The first-offense penalty now scales by BAC tier:

Drug-impaired first offenders are sentenced under the 0.10–0.15% tier (7 months–1 year IID). All tiers also carry mandatory IDRC attendance, a $100 Drunk Driving Enforcement Fund surcharge, a $100 MVC restoration fee, a $100 Intoxicated Driving Program fee, a $75 Safe and Secure Community Program fee, and a $125 surcharge.

Second and Third Offenses

Insurance surcharges stack on top: $1,000/year for 3 years for first and second offenses, $1,500/year for 3 years for third offenses. A second offense within 10 years of the first also triggers a 1-year ignition interlock minimum even at the lower BAC tier.

The 10-Year Step-Down Rule

Prior offenses only count upward if they fall within 10 years. A second offense occurring more than 10 years after the first is sentenced as a first offense; a third offense occurring more than 10 years after the second is sentenced as a second offense. Out-of-state DWI convictions count as priors for step-down purposes — NJ does not let a driver reset the clock by getting drunk across the river.

Refusal to Submit to Breath Testing — N.J.S.A. 39:4-50.4a

Refusal is a standalone offense, separate from DWI, built on NJ's implied-consent law (39:4-50.2). By driving on a public or quasi-public road in New Jersey, you are deemed to have consented to breath testing whenever an officer has probable cause to believe you are impaired. You can be convicted of refusal even if the underlying DWI charge is dismissed, reduced, or never filed — the State only needs to prove the officer had probable cause, read the Attorney General's Standard Statement of consequences, and you refused.

Refusal Penalties

For a first offense, the refusal suspension may run concurrent or consecutive to any DWI suspension from the same incident. For second and subsequent offenses, the refusal suspension must run consecutive to any DWI suspension — meaning a second-offense drunk driver who also refuses can face back-to-back suspensions totaling several years.

What Counts as "Refusal"

Refusal is broader than saying "no." New Jersey courts have found refusal when a driver:

• Remains silent or does not answer
• Gives conditional or ambiguous responses ("I'll take it if my lawyer is here")
• Delays, stalls, or repeatedly asks questions
• Provides weak or short breath samples ("failure to provide adequate sample")
• Fails to follow the officer's instructions

There is no right to counsel before deciding whether to submit to breath testing in NJ. The officer must read the Attorney General's Standard Statement; failing to read it correctly is a defense (State v. Widmaier), and a language barrier that prevents understanding can also defeat a refusal finding (State v. Marquez).

Ignition Interlock Device — N.J.S.A. 39:4-50.17

The ignition interlock device (IID) is the centerpiece of NJ's post-2019 DWI regime. Key rules:

• Mandatory installation in any vehicle the offender owns, leases, or principally operates — the choice of vehicle is the offender's, but the obligation is not optional.
• IID runs during any hard suspension period and for the statutory period after license restoration.
• Only MVC-approved vendors may install and service IIDs; recalibration is required every 60 days (approximately 90 days for some providers).
• Tampering, circumventing, or driving a non-IID vehicle is a separate motor vehicle offense with its own penalties, including additional license suspension.
• A 2023 amendment (effective 2024) allows voluntary early IID installation before conviction: a driver who installs early and obtains an interlock-notated license can earn 2-for-1 credit against the suspension period (1 day credit for every 2 days installed) and may be eligible for a fine waiver — but the credit is not available if the DWI involved an accident causing serious bodily injury.

Elements the State Must Prove for Refusal

The prosecution must establish by a preponderance of the evidence:

1. The officer had probable cause to believe the person was driving while intoxicated on public or quasi-public roads.
2. The person was placed under arrest (where appropriate).
3. The officer read the Attorney General's Standard Statement warning of consequences.
4. The person refused to submit to the test.

Why Officers Must Know These Figures

On the LEE, the test-writer is checking whether you can recall the exact thresholds and tier breakpoints, not just the general idea that "DWI is bad." Memorize the three BAC cut points (0.08, 0.10, 0.15), the three underage/CDL thresholds (0.01, 0.04, 0.08), the IID periods by tier (3 mo / 7–12 mo / 9–15 mo), and the second/third offense jail floors (48 hrs / 180 days). Mixed-up numbers are the most common wrong-answer traps in this section.