Last verified: March 2026
The Standard: Behavioral Impairment
Under 23 V.S.A. §1201, Vermont's DUI law does not set a specific THC blood concentration (ng/mL) that automatically constitutes impairment. Instead, the state uses a behavioral impairment standard — prosecutors must demonstrate that your ability to operate a vehicle was actually impaired by cannabis (or any other substance).
This is different from states like Colorado (5 ng/mL per se limit) or Washington (5 ng/mL). Vermont's approach means that a blood test showing THC alone is insufficient for a conviction — there must be evidence of impaired behavior.
Drug Recognition Expert (DRE) Evaluations
Without a per se THC threshold, Vermont relies heavily on Drug Recognition Expert (DRE) evaluations. DREs are law enforcement officers trained in a 12-step protocol to identify drug impairment, including:
- Pupil size and reaction to light
- Divided attention tests (walk-and-turn, one-leg stand)
- Vital signs (pulse, blood pressure, temperature)
- Muscle tone and injection site examination
- Behavioral observations and interview
A DRE evaluation can be requested after a standard field sobriety test suggests impairment. The DRE's opinion carries significant weight in court proceedings.
DUI Penalty Escalation
| Offense | Max Prison | Max Fine | License Suspension |
|---|---|---|---|
| 1st offense | 2 years | $750 | 90 days |
| 2nd offense | Increased | Increased | 18 months |
| 3rd offense | Increased | Increased | Indefinite |
| 4th+ offense | 10 years | $5,000 | Lifetime |
Medical Card Is NOT a Defense
Having a Vermont medical cannabis card provides no defense or exemption from DUI charges. Medical patients are held to the same behavioral impairment standard as all other drivers. The fact that you have a legal right to consume cannabis does not give you the right to drive while impaired by it.
Vermont's behavioral impairment standard means there is no "legal" amount of THC you can have in your system while driving. If an officer observes impairment and a DRE confirms it, you can be charged regardless of your THC level. Wait at least 4–6 hours after smoking, longer after edibles.
Open Container Rules
Vermont's open container rules for cannabis are strict and apply separately to operators and passengers:
| Violation | Fine |
|---|---|
| Operator: consuming cannabis while driving | $500 |
| Operator: open container in vehicle | $200 |
| Passenger: open container or consumption | $200 |
There is no exception for hire vehicles (taxis, rideshares, limousines). Passengers in all vehicles are subject to the $200 open container fine.
Safe Transport
To transport cannabis legally in your vehicle:
- Keep cannabis in a sealed, original dispensary container
- Store it in the trunk or an area not accessible to the driver or passengers
- If your vehicle has no trunk (SUV, hatchback), keep it in a sealed container as far from the driver as possible
- Never break the seal until you are on private property
For in-depth cannabis education, dosing guides, safety information, and research summaries, visit our partner site TryCannabis.org