Chapter 4: DUI / DWI Laws

Driving while impaired by alcohol or drugs is one of the most dangerous and reckless decisions a person can make behind the wheel. It is a leading cause of traffic fatalities and catastrophic injuries in Colorado and across the nation. Understanding the state’s strict laws, severe penalties, and the science of impairment is absolutely critical for avoiding a decision that can have irreversible and devastating consequences for you and innocent people on the road.

DUI & Implied Consent

In Colorado, it is illegal to operate a motor vehicle while under the influence of alcohol, drugs, or a combination of both. This is not limited to illegal substances; impairment from prescription medications or marijuana is also illegal and carries the same penalties. The state has two primary levels of alcohol-related offenses:

• Driving Under the Influence (DUI): This means a driver’s physical or mental abilities are substantially incapable of safely operating a vehicle.
• Driving While Ability Impaired (DWAI): This is a lesser offense, meaning a driver is affected to the slightest degree by alcohol or drugs, impairing their ability to drive safely.

The state uses Blood Alcohol Concentration (BAC) as a standard measure of impairment. The legal limits are set by law and are not a guideline for when it is “safe” to drive.

• 21 and Over: A BAC of 0.08% or higher constitutes a DUI per se, meaning no further evidence of impairment is needed for a conviction. A BAC between 0.05% and 0.079% creates a permissible inference that the driver is a DWAI.
• Under 21: Colorado has a “Zero Tolerance” law. If a driver under 21 has a BAC between 0.02% and 0.079%, their license will be revoked.
• Commercial Drivers: For drivers operating a commercial vehicle, the BAC limit is much lower at 0.04%.