What Are the Colorado DUI Laws?

Driving under the influence, driving while impaired, or driving with an excessive alcoholic content are all illegal under the umbrella of driving under the influence (DUI) laws in Colorado. These statutes set forth the limits for blood alcohol levels while driving, the rules for testing, and the penalties for driving a motor vehicle while impaired or under the influence of alcohol or one or more drugs.

Blood Alcohol Concentration (BAC) Limits in Colorado

Colorado’s "per se" blood alcohol content (BAC) is 0.08%, meaning that as long as a driver has a .08% BAC, he or she could be convicted of a DUI absent any other evidence of impairment. Colorado also has what is known as an "aggravated DUI" charge, which permits enhanced penalties if the driver has a BAC of 0.17% or higher. Additionally, Colorado enforces a "zero tolerance law" for drivers under the legal drinking age of 21 years old whereby any BAC of 0.02-0.05% could result in an Underage Drinking and Driving infraction conviction.

Colorado DUI Statutes

The following table outlines the specifics of Colorado’s DUI laws.

Code Sections COLO. REV. STATE §42-4-1301, et seq.
BAC Limits

All of these BAC penalties may have you thinking about just refusing any BAC test. However, Colorado has what is known as an implied consent or expressed consent law. Like many other states, Colorado deems any operation of a motor vehicle in the state as consent to submit to a chemical test of your breath, blood, or urine to determine the presence and prevalence of alcohol or other controlled substance in your body. If a police officer has reasonable grounds to believe you are driving under the influence and you refuse a chemical test, your driving privileges can be revoked for up to one year.

Select Penalties

Under Colorado law a person’s driver’s license can be automatically suspended or revoked upon a DUI conviction. Even a first time DUI offense can get your license suspended for 9 months. And if you have been arrested for DUI or have refused a chemical test, you may be required to install an Ignition Interlock Device (IID) in your car. Colorado’s IID law requires you to blow into the device before starting the vehicle and at periodic intervals while driving. If the IID detects an elevated BAC, the vehicle will not start.

Note: State laws are always subject to change through the passage of new legislation, rulings in the higher courts (including federal decisions), ballot initiatives, and other means. While we strive to provide the most current information available, please consult an attorney or conduct your own legal research to verify the state law(s) you are researching.

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Colorado’s drunk driving laws can be complicated, and include harsh punishments if broken. An experienced lawyer can help you determine the best defense possible based on their experience representing DUI cases in the local courts and the facts of your case. Get a free legal review of your case to learn more about how professional legal assistance can help you.

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