The Colorado State Patrol (CSP) is conducting the first enforcement of the state’s must-carry chain law for commercial vehicle drivers this week.
On Thursday, September 4, 2025, CSP is holding a CMV Chain Check Operation on I-70 near Dotsero.
As part of the event, CSP troopers and Port of Entry officers “will be checking all commercial drivers on I-70 to ensure they are carrying chains as required by Colorado State law.”
This is the first CSP chain check event of the winter season since Colorado’s Chain Law went into effect at the start of September. CSP conducts chain checks “when the weather is not expected to be inclement” to ensure driver compliance.
What Is Colorado’s Chain Law For CMV Drivers?
See more on Colorado Chain requirements from CSP below.
All commercial motor vehicle drivers must carry chains from September 1 to May 31. This applies to vehicles with a combined weight of more than 16,000 pounds used in commerce or as a means of 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 mile marker 259 (Morrison) to the Utah border
- Colorado Highway 9 mile marker 63 to mile marker 97 (Frisco to Fairplay)
- Route 40 mile marker 256 (Empire) to the Utah border
- U.S. Route 50 mile marker 225 (Salida) to the Utah border
- U.S. Route 160 mile marker 304 (Walsenburg) to the New Mexico border
- U.S. Route 285 mile marker 250 (Morrison) to the New Mexico border
- All of U.S Route 550
The 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.