Colorado Chain Law Violations and Truck Crash Liability
Key Takeaways
- Colorado’s Must Carry Chain Law requires commercial vehicles to carry chains or approved traction devices from September 1 through May 31, whether or not it is snowing that day.
- CDOT reports that the law covers more than 1,400 centerline miles of highway and that law enforcement issued over 1,300 Must Carry citations during the 2024-2025 chain season.
- A violation is not just a fine. In a personal injury case it is evidence that the carrier disregarded a known, published requirement.
- Two separate failures matter: not carrying the equipment at all, and carrying it but failing to install it when the chain law was activated.
- Because these violations are decisions made before the truck ever left the yard, they usually point at the motor carrier rather than only the driver.
What is Colorado’s chain law?
Colorado’s chain law is really two requirements: a carrying requirement that applies for most of the year, and an activation requirement that applies when conditions call for it.
Under Senate Bill 24-100, commercial motor vehicles must carry chains from September 1 through May 31. The requirement covers I-70 between Dotsero and Morrison and most state and federal highways west of I-25, and it applies regardless of the weather on any given day. A clear, dry September morning does not excuse an empty chain rack.
CDOT reports that the Must Carry Chain Law now reaches more than 1,400 centerline miles of highway, with 130 designated chain stations statewide and 22 of them on the I-70 mountain corridor. The agency also reports that more than 1,300 Must Carry citations were issued during the 2024-2025 chain season.
Separately, CDOT can activate the Commercial Vehicle Chain Law on any state highway when conditions require it. Once activated, vehicles at or above the applicable weight threshold must have chains installed on the required number of drive tires.
How is the commercial chain law different from the traction law?
They apply to different vehicles and impose different requirements, which matters when identifying what a specific truck was obligated to do.
| Traction Law | Commercial Vehicle Chain Law | |
|---|---|---|
| Applies to | Drivers not operating a commercial motor vehicle | Commercial motor vehicles |
| Requirement | Winter, all-weather, or M+S tires with at least 3/16-inch tread, or chains or an approved alternative traction device | Chains or approved alternative traction devices installed on drive tires |
| I-70 corridor timing | September 1 through May 31 between Dotsero and Morrison | Carrying requirement September 1 through May 31; installation when activated |
CDOT has also noted that Colorado’s updated Traction Law requires the tread depth and tire type described above for all four-wheel-drive and all-wheel-drive vehicles. Passenger vehicle drivers who want the practical version can see our winter driving safety tips.
Does a chain law violation prove the trucking company was negligent?
It does not decide the case by itself, but it is unusually strong evidence, because the requirement is published, specific, and known to every carrier operating in the state.
In any Colorado personal injury case, an injured person must prove negligence by establishing a duty, a breach, causation, and damages. A safety statute supplies the duty in writing and makes the breach concrete. The remaining question is causation: did the missing traction actually contribute to the crash?
That question is answerable with physical evidence. Skid and yaw marks, the crash geometry, road surface condition at the time, CDOT closure and condition records, and engine data showing wheel speed and braking all speak to whether traction was the operative failure. Our guide on what truck black box and ELD data shows after a crash covers what the vehicle itself recorded.
Who is responsible when a truck lacks required chains?
Usually the motor carrier, and often more clearly than the driver. Equipment is a company decision made before dispatch, not a judgment call made at 65 miles per hour.
The relevant questions in a claim are:
- Did the carrier equip the truck with chains before sending it into the covered area?
- Did the carrier train the driver on when and how to install them?
- Did the carrier’s schedule leave time for a chain-up stop at a designated station?
- Did dispatch pressure the driver to continue through an activated chain law?
- Does the carrier have a history of chain law citations?
A delivery window that cannot accommodate a chain-up stop is a scheduling decision, and it belongs to the company. This is the same category of direct carrier negligence covered in who is liable in a truck accident besides the driver, and it does not depend on whether the driver was an employee or an owner-operator.
What if the driver had chains but did not use them?
That is a separate failure, and it can be a worse one. Carrying chains and choosing not to install them when the chain law was active reflects a decision made with the equipment in hand.
Timing evidence resolves this. CDOT records establish when the chain law was activated and on which segment. Duty logs and GPS data establish where the truck was and whether it passed a designated chain station without stopping. Chain stations exist precisely because installing chains in a live lane of traffic is itself dangerous, so a driver who passed several of them made a series of choices rather than one.
Schedule pressure often sits underneath that choice, which loops back to the carrier and connects to the same records that prove hours of service violations.
How does the defense respond to a chain law violation?
Three arguments come up repeatedly, and each can be met with evidence rather than assertion.
- The chain law was not active at that moment. CDOT activation records and time-stamped road condition data settle this.
- Chains would not have prevented the crash. This is a causation argument and it is answered by reconstruction, surface condition analysis, and the crash geometry.
- The injured driver contributed to the crash. This is the most common approach in every commercial case. Under Colorado’s modified comparative negligence rule, an injured person found 50 percent or more at fault recovers nothing, so shifting blame is not a discount for the insurer, it is a complete defense.
The records that answer all three are held by the carrier and by CDOT, and the carrier’s portion has a short life. Federal rules require only six months of retention for duty records. The steps involved are covered in preserving evidence after a Colorado truck crash.
Do chain violations only matter in winter?
The chain law itself is seasonal, but the broader assumption that Colorado truck crashes are a winter problem does not hold up. CDOT’s Truck Safety Campaign fact sheet reports that runaway truck ramps are used most frequently in summer, because long descending grades cause heavy truck brakes to overheat and fail through extensive use.
Traction and braking are different failure modes, and a case should be evaluated for both. Our article on brake failure and runaway truck ramp crashes in Colorado covers the mechanical side, and truck crashes on the I-70 mountain corridor covers the corridor as a whole.
What if a government vehicle was involved?
Public plows and maintenance trucks operate throughout the covered highways, and a crash involving one runs under the Colorado Governmental Immunity Act. C.R.S. 24-10-109 requires written notice to the correct public entity within 182 days of discovering the injury, and missing that deadline bars the claim.
The deadlines and current damage limits are covered in injured by a government vehicle in Colorado. For everything else, see our overview of truck accident claims in Colorado.
Frequently Asked Questions
When does Colorado’s chain law apply to commercial vehicles?
Commercial motor vehicles must carry chains from September 1 through May 31 on I-70 between Dotsero and Morrison and most state and federal highways west of I-25. Installation is required when CDOT activates the Commercial Vehicle Chain Law.
Does a truck have to carry chains even when there is no snow?
Yes. The Must Carry requirement applies throughout the season regardless of current weather conditions.
Can a chain law citation be used in my injury case?
A citation is one piece of evidence. The stronger showing usually comes from the underlying facts, including CDOT activation records, the truck’s location and equipment at the time, and the carrier’s compliance history.
Is the driver or the company responsible for missing chains?
Often both, but equipping the truck is a company decision made before dispatch, which frequently places the stronger claim against the motor carrier.
How do I prove the chain law was in effect when I was hit?
CDOT maintains records of when and where chain law restrictions were activated, and those records can be obtained as part of building the claim.
Talk to a Denver truck accident lawyer
A missing set of chains is a decision someone made, and the records showing who made it do not last long. Chalat Hatten & Banker represents seriously injured people and their families throughout Colorado, and there is no fee unless we recover on your behalf. Schedule a free consultation.