Driving and traveling

Plan ahead. Don't drive high.

Driving while impaired is illegal and unsafe

Getting high before you drive can get you arrested for a driving under the influence (DUI) charge. This is true even though marijuana use is legal for adults in Colorado.

  • Similar to alcohol, there’s an established impairment level for marijuana in Colorado.      
    • By law, drivers with 5 nanograms of delta-9 tetrahydrocannabinol (THC) per milliliter of whole blood can be prosecuted for DUI.
  • Even if marijuana is used medically, officers can arrest you for impaired driving.
  • No open containers:
    • Neither drivers nor passengers are allowed to open any marijuana packaging and use the product while in a vehicle, even if you are not moving.
    • You can be charged with a traffic offense if the marijuana product seal has been broken, some of the product has been consumed and there’s evidence that it was used in the car.
  • Check out the Colorado Department of Transportation’s “Uncomfortable High” campaign and read the frequently asked questions for more information on marijuana and driving in Colorado.


Be careful where you travel 

Keep it in Colorado.

  • Leaving the state with any marijuana product is against the law. 
  • You can’t bring marijuana to Denver International Airport or any other airport.
  • Not in federal parks or on federal land:
    • Since marijuana is still illegal under federal law, you can’t use it on federal land, including national parks and national forests. This includes ski slopes.



For occasional consumers, using 10 mg or more of THC is likely to cause impairment. This impacts your ability to drive, bike or perform other safety-sensitive activities.

People may think that they’re “safer” drivers while stoned. However, research shows that driving while high may increase your risk of a crash since your reaction time is slower and your understanding of distance and speed is different. If you’re high, you shouldn’t drive, bike or operate machinery. 

  • Smoking:
    • Wait at least six hours after smoking up to 35 mg of THC before driving or biking. If you’ve smoked more than 35 mg, wait longer.
  • Eating or drinking:
    • Wait at least eight hours after eating or drinking up to 18 mg of THC before driving or biking. If you’ve consumed more than 18 mg, wait longer.
  • Marijuana affects individuals differently.  
    • These times are estimates based on research findings. If you’re unsure how marijuana will affect you, make other plans for transportation or don't drive.
  • Multiple substances:
    • Using alcohol and marijuana at the same time is likely to result in greater impairment than either one alone.