08/02/2025
Colorado law prohibits a person from driving a vehicle while under the influence of
alcohol or drugs or while the person's ability to drive is impaired by alcohol or
drugs. These offenses are often abbreviated as "DUI" and "DWAI," respectively.
Colorado law also prohibits a person under 21 years of age from driving when the
person's breath alcohol content is at least 0.02 but not more than 0.05 at the time of
driving or within two hours after driving, which is referred to as underage drinking
and driving ("UDD").
Blood tests and breath tests play a prominent role in the enforcement of drunk
driving laws, although DUI or DWAI can be proved by other means, such as saliva or
urine. If at the time of the commission of an alleged offense, or within a reasonable
time thereafter, a person's blood alcohol content or breath alcohol content
(collectively, "BAC") exceeds 0.05 but is less than 0.08, there is a permissible
inference that the person's ability to operate a vehicle was impaired. If the person's
BAC is 0.08 or more, there is a permissible inference that the person was under the influence of alcohol.
A person whose BAC is 0.08 or more at the time of driving or within two hours after driving commits DUI per se.
“Driving under the influence" (DUI) means driving a vehicle when a person has consumed alcohol or one or more drugs, or a combination of alcohol and one or more drugs, that affects the person to a degree that the person is substantially incapable, mentally or physically, to exercise clear judgment,sufficient physical control, or due care in the safe operation of a vehicle.
§ 42-4-1301 (1) (f), C.R.S.
"Driving while ability impaired" (DWAI) is similar, except that a person need only be affected to the slightest degree so that the person is less able to drive than the person ordinarily would have been.
§ 42-4-1301 (1) (g), C.R.S.
§ 42-4-1301 (2)(d), C.R.S