Colorado's Chain Law
Winter driving conditions can be expected in the Colorado high country as early as September and as late as May. Travelers must be prepared to drive safely at all times and in all conditions. View the winter driving guide to help you safely navigate our beautiful mountain roads during these winter months.
Colorado's Chain Law is not just for Large Commercial Vehicles. All vehicles need to be prepared to have adequate tires and equipment when traveling in Colorado during the winter. Chain Law and safe tire requirements can be put into effect at any time for all types of vehicles. These requirements have recently changed.
Larger Vehicles, Including Recreational and Commercial Motor Vehicles
As of August 7, 2024, all commercial motor vehicle drivers must carry chains carry chains from September 1 to May 31. This applies to vehicles with a combined weight of more than 16,000 lbs used in commerce or as transport for at least 16 passengers (including the driver) on public highways. View the Colorado chain up tips (consejos para colocar cadenas en Colorado) handout for more information on what must be carried by CMVs.
Commercial vehicles and buses have a larger footprint on roadways where chains are required. CMVs must carry chains or ATDs on all the following roads regardless of current weather:
- I-70 west of milepost 259 (Morrison) to the Utah border.
- Colorado Highway 9 mile post 63 to milepost 97 (Frisco to Fairplay).
- Route 40 milepost 256 (Empire) to the Utah border.
- U.S. Route 50 milepost 225 (Salida) to the Utah border.
- U.S. Route 160 milepost 304 (Walsenburg) to the New Mexico border.
- U.S. Route 285 milepost 250 (Morrison) to the New Mexico border.
- All of U.S Route 550.
Those required to chain 4 drive tires:
- Straight Trucks: 4 tire chains, 4 AutoSocks, 4 tire cables 0.415 diameters or greater, auto chains, or sanders.
- Single Drive Axle Combinations: 4 tire chains, 4 AutoSocks, auto chains, or sanders. No cables are allowed.
- Tandem Drive Axle Combinations: 4 tire chains, 4 AutoSocks, 4 tire cables 0.415 diameter or greater, auto chains, or sanders. If chains are on the 2 outside tires of one drive axle, any tire cable may be used to cover 2 tires on the other drive axle. AutoSocks may be used to cover 2 tires on the other drive axle. AutoSocks and tire cables cannot be used together.
- Auto Transporters: 4 tire chains, 4 AutoSocks, 4 tire cables 0.415 or greater, auto chains, or sanders. Do not use chains if use places hydraulic lines at risk of damage (alternative traction devices (ATDs) may be used to mitigate the risk). Travel will be restricted if the vehicle is unable to chain.
Those Required to chain 2 drive tires:
- Buses: 2 tire chains, 2 tire cables 0.415 diameters or greater, 2 AutoSocks, auto chains, or sanders.
- Hot shot trucking: Traditional motor vehicles (such as pickup trucks) that are pulling trailers and meet the above-listed weight criteria must also carry chains. 2 tire chains for singles (to affix to rear tires). Exception: Duallies need 4 tire chains.
For more safe driving tips, visit Truck Safety Campaign-The Mountain Rules.
Smaller Vehicles, Including Passenger Cars and Trucks with Two-Wheel and Four-Wheel Drive
All two-wheel drive motor vehicles with a GCWR/GVWR less than 16,001 pounds traveling on any portion of I-70 between mile point 259 (Morrison) and mile point 133 (Dotsero) from September 1 through May 31 must have:
- Tire chains for two or more drive tires; or
- An approved ATD for two or more drive tires; or
- Tires with a tread depth of at least 3/16-inch and which are rated for either “All weather” or “Mud and Snow” (indicated by a “All Season”, M+S, M/S, etc. on sidewall) by the manufacturer. This is indicated on the side of the tire by “M+S”, “M/S” or an icon of a mountain with a snowflake.
All four-wheel drive motor vehicles less than 16,001 pounds traveling on any portion of I-70 between mile point 259 (Morrison) and mile point 133 (Dotsero) from September 1 through May 31 must have tires with a tread depth of at least 3/16-inch and be adequate for winter driving conditions.
Penalty for non-compliance: $50 fine plus a $17 surcharge.
There are three types of restrictions (commonly referred to has chain laws) which may be placed in effect on roadways in Colorado.
To be disqualified by an appointing authority upon admission or confirmation of:
- The passenger traction law requires two-wheel drive passenger vehicles to have all weather or mud and snow rated tires with adequate tread or to affix chains or alternate traction devices (ATDs). Four/all-wheel drive vehicles must have all drive wheels engaged and tires with adequate tread depth.
The Passenger Vehicle Chain Law imposes the most restrictive requirements during inclement weather. All passenger vehicles must have chains or alternate traction devices (ATDs) on two or more drive tires. This applies to every two/four/all-wheel drive passenger vehicle in the affected area.
The Commercial Motor Vehicle Chain Law is a requirement for all large vehicles to affix chains or alternate traction devices (ATDs) to all drive tires (up to four). Even though it has "commercial" in the name, the requirement is based on the Gross Vehicle Weight Rating (GVWR) or Gross Combined Weight Rating (GCWR) for the vehicle regardless of its use (private or commercial).
Penalty for non-compliance with winter driving restrictions: Up to a $500 fine plus a $79 surcharge or, if you are stuck and blocking any traveled portion of the roadway the fine is $1,000 plus a $157 surcharge.
How will the different chain law restrictions be announced?
At a minimum, the Colorado Department of Transportation (CDOT) will notify the public of the travel restriction with erected static and electronic variable message roadway signs. Additionally, CDOT may utilize radio channels, the official CDOT travel website (cotrip.org), phone message system, email, text and other automated personal notification systems.
