Can You Get a DWI With a BAC Under 0.08 in New Jersey?

New Jersey's DWI Law Has Two Ways to Convict You, Not One

Most people think of a DWI as a number: blow over 0.08%, get charged. That's true for one part of New Jersey's statute, N.J.S.A. 39:4-50 — but it's only half of it. The law also allows a conviction based purely on being "under the influence" of alcohol or drugs, evaluated through observed impairment rather than a breath or blood reading. These are two separate, independent ways to prove the same offense, and prosecutors don't need both.

That means a driver who blows a 0.06%, refuses the test entirely, or is never tested at all can still be charged and convicted — if the evidence shows their driving ability was meaningfully impaired.

What "Under the Influence" Actually Means in Court

New Jersey courts define "under the influence" as a substantial deterioration or diminution of a driver's mental faculties or physical capabilities — in plain terms, that the person's ability to drive safely was noticeably worse than a sober driver's would be in the same circumstances. There's no minimum BAC tied to this standard. It's a fact-based determination built from everything an officer observed and documented at the scene.

This is different from the 0.08% prong, which is what lawyers call a "per se" violation — the number itself establishes the offense as a matter of law, full stop. The impairment prong has no such shortcut. It has to be proven with evidence.

Why Officers Still Arrest Below 0.08

A few common situations lead to impairment-based charges:

• A refused breath test. If a driver refuses the Alcotest, there's no BAC number at all — but that doesn't end the case. See our page on refusing field sobriety and breath tests in New Jersey for how refusal itself is handled separately, and our page on medical inability to complete a breath test for when a failed attempt isn't a refusal at all.
• A low reading that doesn't match the observed behavior. If a driver was swerving, failed field sobriety tests, and admitted to drinking, but the Alcotest comes back at 0.05% or 0.06%, officers can still pursue the impairment prong.
• Drug impairment with no alcohol involved. Because there's no per se threshold for most drugs the way there is for alcohol, drug-related DWI cases routinely rely on the impairment standard — see our pages on prescription drug DWI and marijuana DWI in New Jersey.
• No breath test was administered at all due to a medical issue, equipment problem, or the circumstances of the stop.

Common Scenarios: Who Gets Charged Below the Per Se Limit

In practice, most impairment-only cases come down to the officer's account of the stop: how the vehicle was driven before the stop, what the driver said and how they said it, and how they performed on field sobriety tests. Bodycam and dashcam footage has become central to these cases because it's often the clearest independent record of what actually happened — see our page on dashcam and police video evidence in NJ DWI cases for how that evidence gets used and challenged.

Defending an Impairment-Based DWI Is Different From Defending a BAC Case

A case built on a 0.09% Alcotest reading is fought largely by challenging the reliability of that number — calibration records, the observation period, the machine's maintenance history (see our page on challenging the Alcotest in New Jersey). A case built on observed impairment is fought differently: by challenging the officer's subjective observations, how the field sobriety tests were administered and scored, whether the stop itself was legally justified, and whether the video actually supports the officer's account. It's a more evidence-and-testimony-driven fight, which is exactly why it benefits from being reviewed closely rather than assumed to be a lost cause simply because there's no high number attached.

The Bottom Line

A BAC under 0.08% is not a get-out-of-jail card in New Jersey. If you were arrested and charged despite blowing under the limit — or refusing the test — the case against you rests entirely on the officer's observations and the surrounding evidence, which means it can be examined and challenged in ways a straightforward per se case cannot. Understanding which prong the state is actually relying on is the first step to building a defense.