Independent Colorado statute reference
Denver DUI Law Guide
The statute, read plainly.
What Colorado's impaired driving laws actually say about DUI, DWAI, BAC numbers, THC, test refusal, license revocation and sentencing, with the statute named every time and a reminder to check the current version.
What this guide is
A reading companion for Colorado DUI law
Most pages about Denver DUI law are written to sell a consultation. This one is written to be read before, or next to, that consultation. We take the sections of the Colorado Revised Statutes that govern impaired driving, quote the operative words, and explain how the pieces fit: the offense definitions, the evidence rules, the license system and the sentencing scheme.
We are not a law firm and we don't know anything about your case. What we can do is make the vocabulary familiar, so the conversation with a licensed Colorado attorney starts at a higher level.
- 42-4-1301DUI, DWAI, DUI per se, underage drinking and driving, evidence inferences
- 42-4-1301.1Express consent: breath and blood tests, the two-hour window
- 42-2-126Administrative revocation for an excess BAC or a refusal
- 42-2-132.5Ignition interlock and early reinstatement
- 42-4-1307Sentencing for DUI, DWAI and repeat offenses
- 24-72, Part 7Criminal record sealing (general rules)
Sheet 01 / Definitions
Four Definitions the Colorado Statute Turns On
Nearly every argument in a Colorado impaired driving case comes back to which of these four labels fits the facts. Hover or tap a cell below to read each one; click a cell to hold it.
01 / C.R.S. 42-4-1301(1)(a)
Driving under the influence
Under the influence means alcohol, drugs or both have left the driver substantially incapable, mentally or physically, of exercising clear judgment, sufficient physical control or due care in driving. The test is the driver's condition, not a number.
02 / C.R.S. 42-4-1301(1)(b)
Driving while ability impaired
Impaired means alcohol, drugs or both affected the driver to the slightest degree, so the person was less able than normal to drive safely. A lower bar than DUI, with lower sentencing ranges, and it still counts as a prior offense later.
03 / C.R.S. 42-4-1301(2)(a)
DUI per se
A separate offense defined by a number: 0.08 or more grams of alcohol per hundred milliliters of blood, or per 210 liters of breath, within two hours of driving. No proof of bad driving is needed for this count.
04 / C.R.S. 42-4-1301(6)
Drug DUI and THC
DUI and DWAI cover drugs as well as alcohol. For marijuana, 5 nanograms or more of delta-9 THC per milliliter of whole blood supports a permissible inference that the driver was under the influence. An inference can be rebutted.
Interactive
Where the BAC Lines Sit in Colorado Law
Move the slider to see which statutory lines a blood or breath alcohol number crosses. It shows what the statute says about a number, never what will happen in a case. Breath and blood results, timing and testing procedure all matter.
0.060g / 100 ml blood
Above 0.05, below 0.08
Inference of DWAI (impaired)
In this range the law permits an inference that the driver was impaired by alcohol, which matches the DWAI offense.
Information only. Not a calculator of anyone's BAC and not legal advice. Statute citations last checked November 2026.
Sequence
How a Colorado DUI Case Moves
Five stages, in the order they usually happen. Two of them belong to the DMV and the rest to the courts, which is the single most misunderstood fact about a Colorado DUI.
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01
The Stop.
Contact usually starts with a traffic violation, a crash or a checkpoint. What the officer saw and wrote down at this point becomes the backbone of the police report. Colorado DUI laws
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02
The Test.
Express consent applies: breath or blood, generally within two hours of driving. A refusal is its own event with its own consequences. Express consent rules
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03
The Notice.
An excess result or a refusal can lead to a written revocation notice. It starts a DMV clock that has nothing to do with the court date. License revocation
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04
The Hearing.
The driver can ask the DMV for an administrative hearing within a short deadline printed on the notice. Miss it and revocation generally follows. The DMV hearing steps
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05
The Court.
The criminal case runs separately: arraignment, motions, plea or trial, and if convicted, sentencing under C.R.S. 42-4-1307. Colorado DUI penalties
Six guides
Read Colorado DUI Law One Statute at a Time
Each guide covers one part of the law in depth, names the sections it relies on, and ends with the questions worth taking to a lawyer.
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Colorado DUI Laws
Offense definitions, BAC thresholds, under-21 and commercial lines, and how the inferences work.
C.R.S. 42-4-1301
Read the Colorado DUI Laws guide -
Drug DUI and THC
What the 5 ng THC inference does and does not mean, prescriptions, and alcohol plus drugs.
C.R.S. 42-4-1301(6)
Read the Drug DUI and THC guide -
Express Consent and Refusal
Breath or blood, the two-hour window, and what a refusal sets in motion.
C.R.S. 42-4-1301.1
Read the Express Consent and Refusal guide -
License Revocation and Interlock
The DMV case, hearing requests, interlock and early reinstatement.
C.R.S. 42-2-126 / 42-2-132.5
Read the License Revocation and Interlock guide -
Penalties to Felony DUI
Sentencing ranges, Level II education and therapy, felony DUI, and record sealing.
C.R.S. 42-4-1307
Read the Penalties to Felony DUI guide -
Questions for a Lawyer
An interactive checklist of questions for a first consultation with a DUI lawyer.
Checklist
Read the Questions for a Lawyer guide
How to use this guide: read the statute itself, verify the current version, ask a licensed lawyer.
Colorado's legislature amends Title 42 most sessions, and court decisions change how the words are applied. Every guide here carries the month we last checked it, links to the official text, and stops where legal advice would begin.
Questions readers ask
Denver DUI Law Questions, Answered From the Statute
Is DWAI a lesser offense than DUI in Colorado?
Yes. DWAI (driving while ability impaired) is defined in C.R.S. 42-4-1301(1)(b) as being affected by alcohol or drugs "to the slightest degree," while DUI requires being substantially incapable of safe driving. DWAI carries lower sentencing ranges, but a DWAI conviction still counts as a prior if there is a later alcohol or drug driving case. Read the Colorado DUI laws guide for the full comparison.
What is the legal BAC limit for driving in Colorado?
For adults, a blood or breath alcohol content of 0.08 or more within two hours of driving is the DUI per se offense. Results above 0.05 and below 0.08 support an inference of impairment (DWAI). Drivers under 21 face a separate 0.02 line, and commercial drivers a 0.04 line. The BAC explorer above walks through each threshold.
Is the DMV license case separate from the criminal DUI case?
Yes. The Colorado Division of Motor Vehicles can revoke a license through an administrative process under C.R.S. 42-2-126, and that runs on its own timeline next to the criminal case in court. The two have different deadlines, different standards and different outcomes. See the license revocation guide.
What happens if a driver refuses a chemical test in Colorado?
Colorado's express consent law (C.R.S. 42-4-1301.1) treats every driver as having agreed to a breath or blood test when an officer has probable cause. Refusing does not stop the case: it leads to its own license revocation, the refusal can be used as evidence at trial, and it can bring persistent drunk driver conditions. The express consent guide explains the rules.
Does this website give legal advice or recommend a lawyer?
No. DUI Denver Law Guide is an independent legal information resource, not a law firm. It does not review cases, recommend specific attorneys or create an attorney-client relationship. It does offer a checklist of questions to take to a licensed Colorado attorney you choose.
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Next step
Bring better questions to a Colorado DUI lawyer
The lawyer questions checklist turns the guides into a list you can tick off during a first consultation. For anything about this site itself, use the general inquiry form; please do not send details of a case.
This guide cannot review a case. A licensed Colorado attorney can. Bring the checklist; keep the details of your case for that conversation.