Can I Legally Drive After Smoking Marijuana in Colorado?

Chemical test for DUI

In the state of Colorado, the

recreational use of marijuana isn’t just decriminalized, it’s



So long as a user is only in possession of one ounce of marijuana or less, and
so long as they are at least 21 years of age, the use of marijuana is not
against the law. (Possession of one to two ounces is a petty offense.) However,
that does not mean that there aren’t conditions to this use.

For example, marijuana is considered to be an
impairing substance and, therefore, the use of marijuana before driving may
indeed be an offense. Here’s what you should know about your ability–or
inability, rather–to legally drive after smoking or otherwise using marijuana
in Colorado:

Laws on Impaired Driving

Per Colorado statutes, it is unlawful for a person to drive while under the influence of alcohol or drugs of any type, including


drugs, such as prescription drugs or, in this case, marijuana. Because you cannot judge your own level of impairment after using marijuana, it is strongly recommended to


drive after consuming/using THC (tetrahydrocannabinol), the active ingredient that results in a “high” sensation.

Much Can I Legally Use and Drive?

You can be convicted of driving while impaired if you have consumed/used any impairing substance and you are “

under the influence

” of such a substance and your ability to safely operate a motor vehicle is impaired as such. In terms of “how much” marijuana in your blood will serve as an automatic presumption of impairment, the law reads that having five (or more) nanograms of active THC in one’s blood while operating a motor vehicle can result in prosecution for a DUI (driving under the influence) offense. Again, note that even if the level of active THC in your blood is less than this, a police officer may have probable cause to arrest you regardless based on their

observed level of impairment


The prohibition on using marijuana and driving
stands both for recreational users of marijuana


users of medical marijuana. Just like an over-the-counter drug,
you cannot lawfully use


that is impairing and then get behind the wheel of a car.


One common question that people who use
marijuana have is how a law enforcement officer will even be able to deduce
that one has used the drug prior to driving.

  • Advanced Roadside Impaired Driving Enforcement (ARIDE) Training.

    In the state of Colorado, many of our law enforcement officers have
    received ARIDE training, which means that they have advanced knowledge of how
    to detect drug impairment.

  • Blood testing.

    The other way to determine
    whether or not an individual has used marijuana is to perform a blood test.
    While you maintain the right to refuse to submit to a blood test, if you do,
    your driver’s license will be revoked, and you will automatically be labeled as
    a “high-risk driver.”

Laws Related to Marijuana and Driving

Note that in addition to the law prohibiting
impaired driving, whether as a result of alcohol consumption or drug use,
Colorado also has an open container law on the books. This law


makes it illegal to have
marijuana-related paraphernalia in the car, as well as any open containers of

Against Drugged Driving

If you have been arrested and charged with a
DUI as a result of allegations that you were operating a vehicle while impaired
from marijuana use, you need a skilled DUI attorney on your side. Potential
defenses against drug driving charges include a lack of proof that you had used
marijuana, an improperly administered roadside sobriety test, an unlawful stop
or vehicle search, evidence that you had used marijuana but were no longer
under the influence at the time you were driving, and many others. If you are
convicted, you can face serious penalties – it is strongly recommended that you
seek the counsel of a knowledgeable attorney as soon as possible in order to
start building your defense and considering your options.

Our Colorado DUI Attorneys Today

The laws surrounding marijuana use and driving
can be confusing and unclear. But if you are arrested for driving while under
the influence of marijuana, one thing is certain: you need a skilled attorney.
At the law offices of Anderson & Carnahan Attorneys at Law, our experienced
Colorado criminal defense lawyers have worked on marijuana-involved DUI cases and
understand what it takes to protect our clients’ best interests. To schedule a
consultation with our firm today, please send us a message, visit our law
office in person, or call us directly at 719-473-9099.