Yes, it can. And this catches a lot of people off guard.
Since the Marihuana Regulation and Taxation Act (MRTA) legalized recreational cannabis in New York in 2021, many people assume they are in the clear as long as they are using a legal product. But legalization changed the rules around possession — it did not change the rules around driving. Operating a vehicle while impaired by cannabis is still a criminal offense under VTL 1192(4), carrying the exact same penalties as a standard alcohol DWI.
The disconnect between “legal to use” and “illegal to drive after using” is where most people run into trouble.
What the Law Actually Says
New York’s impaired driving statute does not distinguish between legal and illegal substances. It says that no person shall operate a motor vehicle while their ability to do so is impaired by the use of a drug. Cannabis is a drug under this statute, regardless of its recreational or medical status.
If police can establish that THC impaired your ability to drive to any degree, you can be charged with DWAI-Drugs — Driving While Ability Impaired by Drugs. That is a misdemeanor crime. Not a traffic ticket. Not a violation. A criminal charge that goes on your record.
The NY Governor’s Traffic Safety Committee has been explicit on this point: driving under the influence of cannabis continues to be a misdemeanor, and burning cannabis inside a vehicle is separately illegal under the open container law (VTL 1227).
The THC Testing Problem
This is where marijuana DWI cases fundamentally differ from alcohol cases, and it is the single most important thing to understand about how these charges work.
With alcohol, a breathalyzer gives a number. That number — your BAC — tells the court something meaningful about how impaired you were at the time of driving. If it is 0.08% or higher, the number alone is enough to convict.
There is no equivalent number for THC. New York has no legal limit, no per se threshold, and no roadside device that can measure cannabis impairment in real time.
THC behaves completely differently from alcohol in the body:
| Alcohol | THC (Cannabis) | |
|---|---|---|
| Detection Method | Breathalyzer (real-time) | Blood or urine test (delayed) |
| Legal Limit | 0.08% BAC | None — “impaired to any extent” |
| How Long Detectable | Hours after consumption | Days to weeks after consumption |
| Detection = Proof of Impairment? | Yes (above 0.08%) | No — presence alone is not proof |
| Metabolites vs. Active Drug | N/A — breath test measures active alcohol | Blood may show inactive THC metabolites, not active impairment |
This gap between detection and impairment is the core issue. A regular cannabis user can test positive for THC metabolites in a blood test days after their last use, long after any impairing effects have worn off. A urine test can show positive results for weeks.
So when the prosecution presents a positive drug test as evidence, it really only proves one thing: that you used cannabis at some point in the recent past. It does not prove you were impaired while driving.
How Police Build a Marijuana DWI Case
Without a number to rely on, police have to build the case through observations and expert testimony. The typical process looks like this:
The traffic stop. The officer documents the reason for the stop — swerving, running a light, involvement in an accident — and then notes everything they observe: the smell of marijuana, bloodshot eyes, slow speech, confusion, or delayed responses.
Field sobriety tests. The officer administers standardized field sobriety tests, which were designed for alcohol but are used as a general impairment screen. Poor performance combined with a low or zero breathalyzer result is what typically triggers a drug investigation.
The Drug Recognition Expert. A DRE conducts a 12-step evaluation looking for physical signs consistent with cannabis impairment: dilated pupils, elevated pulse, bloodshot eyes, impaired time estimation, body tremors, and a distinct lack of convergence in the eye examination. The DRE then forms an opinion about whether cannabis is the cause.
Chemical testing. A blood or urine sample is collected to confirm the presence of THC or THC metabolites. Remember: this confirms presence, not impairment. Refusing that test triggers separate penalties under New York’s implied consent law.
Each of these steps involves subjective judgment, and each one can be challenged by an experienced DWI defense attorney.
The Edibles Timing Problem
This is a scenario that is becoming more common as edibles become mainstream: someone consumes a cannabis edible hours before driving, believing the effects have worn off, and then gets pulled over for an unrelated traffic violation.
Edibles work differently from smoking. They take longer to take effect (typically 30 minutes to 2 hours), the effects can last significantly longer (4 to 8 hours or more), and the peak impairment period is harder to predict. A person who feels completely sober may still be processing THC in a way that shows up on a blood test — and may still be exhibiting subtle signs that a DRE interprets as impairment.
This timing unpredictability makes edibles-related DWI cases especially complicated for both prosecution and defense.
Medical Marijuana Cards Do Not Help
If you have a medical marijuana card, it will not shield you from a DWAI-Drugs charge. The law treats medical cannabis exactly like any other legal drug: if it impairs your driving, you can be charged. This is the same principle that applies to prescription medications and OTC drugs — legality of the substance is irrelevant when it comes to impairment behind the wheel.
That said, the lack of a per se limit for cannabis means that medical marijuana cases often come down to the strength of the DRE evaluation and the officer’s observations. An attorney familiar with DWAI-Drugs defense can challenge the reliability of both.
The Cannabis-Plus-Alcohol Combination Risk
One scenario that is particularly risky — and increasingly common — is combining cannabis with even a small amount of alcohol. If your BAC comes back below 0.08% but the officer suspects the combined effect of alcohol and cannabis caused your impairment, you can be charged with DWAI-Combination under VTL 1192(4-a).
The penalties for DWAI-Combination are the same as a standard DWI: misdemeanor, up to one year in jail, $500 to $1,000 in fines, and a minimum six-month license revocation. The prosecution has to prove the combined effect caused impairment, which adds complexity — but it also means you are facing a more serious investigation from the outset.
Penalties for a Cannabis DWAI-Drugs Conviction
Since DWAI-Drugs is classified as a misdemeanor (the same level as an alcohol DWI), the penalties are significant:
| Offense | Fines | Max Jail | License Action | IID Required? |
|---|---|---|---|---|
| First DWAI-Drugs | $500 – $1,000 | Up to 1 year | 6-month revocation (min.) | Yes — 12 months minimum |
| Third, within 10 years (Felony) | $1,000 – $5,000 | Up to 4 years | 1-year revocation (min.) | Yes |
| Third within 10 years (Felony) | $2,000 – $10,000 | Up to 7 years | 1-year revocation (min.) | Yes |
A first conviction also requires enrollment in the Drinking Driver Program (which covers drug-impaired driving as well), a mandatory surcharge, and a three-year probation term. A second conviction within 10 years automatically becomes a Class E Felony.
Why Marijuana Cases Are Defensible
Here is the thing that makes cannabis DWI cases different from most alcohol cases: the prosecution has to work a lot harder to prove impairment, and there are more places where their case can fall apart.
The smell issue. Under the MRTA, the odor of cannabis alone cannot be used as probable cause for a stop, search, or arrest — except when police are specifically investigating impaired driving. That is a narrow exception, and defense attorneys can challenge whether the officer crossed the line.
The testing gap. A positive THC test without strong observational evidence is a weak case. If the DRE evaluation was incomplete, if the officer’s observations do not clearly point to impairment, or if there is an alternative explanation (fatigue, medical condition, nervousness), the chemical test alone is not enough.
The DRE’s subjectivity. The entire DRE evaluation is opinion-based. The officer’s training, certification status, protocol compliance, and documentation quality can all be challenged. Research on DRE accuracy for cannabis specifically is less established than for other drug categories.
The timing question. If hours passed between your last use and the traffic stop, the prosecution faces a real challenge in proving you were impaired at the time of driving rather than simply having THC in your system from earlier use.
This is why, as defense practitioners have observed, marijuana DWAI cases tend to see higher rates of dismissals, reductions, and favorable outcomes compared to alcohol DWI cases with clear BAC evidence.
What You Should Do
If you use cannabis — recreationally or medically — and you drive in New York, a few things are worth keeping in mind:
There is no safe “waiting period” equivalent to the one-drink-per-hour rule for alcohol. THC affects people differently based on tolerance, consumption method, and individual metabolism. The safest approach is not to drive for several hours after smoking and longer after consuming edibles.
If you are stopped, do not volunteer information about cannabis use. You have the right to remain silent. Do not consent to a vehicle search. And if you are arrested and facing a chemical test, understand the consequences of both taking and refusing the test before making a decision.
The DWI TEAM represents drivers facing marijuana and cannabis-related DWAI-Drugs charges across New York. If you have been charged, we can review the DRE evaluation, challenge the chemical test evidence, and build a defense strategy around the specific weaknesses in your case.
Disclaimer: This overview is for informational purposes only and does not constitute legal advice. Every case is unique — contact our New York DWI lawyers for personalized guidance.
