Colorado truck chain law
Commercial vehicles 16,001 lb and up must carry chains or alternate traction devices on listed mountain corridors from September 1 through May 31, whatever the weather.
| Type | Must carry chains (dated or standing rule) |
|---|---|
| Carry season / effective dates | September 1 through May 31 every year (C.R.S. 42-4-106(5)(a)(I)(C)). The current corridor list took effect August 7, 2024. |
| Who must carry chains | Commercial vehicles with a declared GVWR of 16,001 lb or more, and vehicles used to carry 16 or more passengers including the driver (Colorado State Patrol). CSP notes the chain-up rule itself is based on GVWR/GCWR, private or commercial use. |
| When you must chain up | When CDOT activates the Commercial Vehicle Chain Law (signs, including electronic signs): chains or ATDs on at least four drive tires for vehicles with four or more drive wheels; buses chain at least two drive tires. |
| Where | I-70 west of MP 259 (Morrison) to Utah; CO 9 MP 63–97 (Frisco–Fairplay); US 40 west of MP 256 (Empire); US 50 west of MP 225 (Salida); US 160 west of MP 304 (Walsenburg); US 285 west of MP 250 (Morrison); all of US 550 (MP 0–130). |
| Penalty | Up to a $500 fine plus a $79 surcharge for not complying with winter driving restrictions; $1,000 plus a $157 surcharge if you are stuck and blocking a travel lane (Colorado State Patrol). CDOT says failing to carry chains can bring a $500 fine. |
| Law | C.R.S. 42-4-106(5) |
Official sources
Checked 2026-10-29. Chain controls are set live by the state, so follow posted signs and officers. Not legal advice.
Running the mountains this winter? Estimate fuel tax with the IFTA calculator and see Colorado IFTA rates.