From September 1 to May 31, Colorado Chain laws apply to all drivers big and small. When the weather is mild on the front range, it’s hard to imagine potential snowfall in Colorado’s high country, but weather and driving conditions can change very quickly with elevation changes. It’s also important to note that Colorado’s Chain Law is not just for large commercial vehicles. Regardless of what you drive, are you prepared for winter mountain driving?
According to Colorado’s law, all vehicles must be prepared with adequate tires and equipment when traveling in Colorado during winter. Here is what you need to know based on your vehicle type:
Larger Vehicles, Including Recreational and Commercial Motor Vehicles
As of August 7, 2024, all commercial motor vehicle drivers must carry chains (Spanish Translation) 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.
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.
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.
Chain law restrictions are announced through the Colorado Department of Transportation (CDOT). At minimum, they will notify the public on static and electronic variable message roadway signs. In addition, this information is regularly announced through 511 traveler information, the official CDOT travel website, and media outlets.
Help us make this a safe and enjoyable winter in Colorado. If we all prepare our vehicles and plan our trips before leaving, we can all enjoy another beautiful winter in colorful Colorado.