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Cannabis and driving in Maryland

Driving while impaired by cannabis is illegal in Maryland. Using cannabis while a vehicle is being driven is also illegal, for the driver and for a passenger. There's no blood-THC number like the 0.08 used for alcohol. Officers judge impairment through field sobriety tests and, in some cases, a trained Drug Recognition Expert.

The DUI law itself

Maryland law makes clear that using cannabis while driving, by the driver or a passenger, and impaired driving are both illegal. If an officer observes signs of impairment, they can make an arrest based on a standard roadside field sobriety test, the same method used for alcohol.

Why there's no THC number

Alcohol has a legal limit: 0.08. Cannabis doesn't work that way in Maryland. There's no blood-THC threshold that automatically makes you impaired or automatically clears you. Instead, officers rely on what they observe: how you're driving, how you perform on a field sobriety test, and sometimes evaluation by a Drug Recognition Expert trained to spot drug impairment specifically.

No smoking in the car

Criminal Law §10-125 prohibits passengers from smoking cannabis in a vehicle on a highway. Its exceptions for alcohol in certain vehicles do not extend to cannabis smoking. Transportation §21-903 separately prohibits a driver from smoking or consuming cannabis, including in a vehicle stopped on a highway.

Storage is not permission to drive impaired

The open-container provision in Criminal Law §10-125 concerns alcohol. That does not override cannabis possession limits, the ban on smoking in vehicles, or impaired-driving law. Keep cannabis secured away from children and pets, and do not drive impaired.

The odor rule

Criminal Procedure §1-211 prohibits a stop or search based solely on cannabis odor. Impaired-driving investigations remain possible, but the statute also limits the areas officers may search when cannabis impairment is the sole basis of an investigation. The circumstances matter; this is not a blanket rule allowing a search whenever some other evidence is present.

Edibles and driving

Edibles can take effect slowly, and impairment may last longer than expected. A fixed waiting period cannot establish that you are fit to drive. Arrange a sober ride or stay put.

Rideshare

Rideshare companies set their own rules about cannabis in the car, and drivers can cancel a ride if they think you've been using it. Don't plan on using cannabis during a rideshare trip. If you've already used it before the ride, that's the point of calling one instead of driving yourself.

Plan ahead

Arrange a sober driver or another ride before any cannabis use. Do not rely on feeling less high as proof that you can drive without impairment.

Every shop in our directory of licensed Maryland dispensaries comes from the state’s own license list, with hours and payment details where the shop publishes them.

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Common questions

Can police search my car just because they smell cannabis?
No. Criminal Procedure §1-211 prohibits stops and searches based solely on cannabis odor. An impaired-driving investigation is still possible, subject to the statute’s restrictions.
Is there a legal THC limit for driving in Maryland?
No. Unlike alcohol's 0.08 limit, Maryland has no blood-THC number. Officers judge impairment through field sobriety tests and, sometimes, a Drug Recognition Expert.
Can I get a DUI the day after using cannabis?
Maryland doesn't set a fixed waiting period. What matters is whether you're impaired at the moment you're driving, not how many hours have passed.
Does a sealed package make it legal to drive after cannabis use?
No. How cannabis is packaged does not change the prohibition on impaired driving. Arrange a sober ride if you have used cannabis.
Can a passenger smoke cannabis while I'm driving?
No. The law bans smoking cannabis in the passenger area of a vehicle on a highway for passengers just as much as the driver.
Can I use cannabis in a rideshare?
Do not smoke cannabis during a rideshare trip. The passenger smoking prohibition applies, and the ride service may impose additional rules.
How long should I wait to drive after an edible?
There is no fixed waiting period that establishes you are fit to drive. Edibles can take effect slowly and impairment may last longer than expected. Arrange a sober ride or stay put.

Sources

This page is general information, not legal or medical advice. Rules change; check the sources above before acting on anything here.

Published by Weed in Maryland, an independent directory. Notice an error? Report a correction.