As of Sept. 1 Expanded CMV Must Carry Law is in effect. For more information on this expansion please visit Chain Up Tips.

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Chain Up Tips

New Update to the 'Must Carry' Law

Beginning on September 1, 2024 all Commercial Motor Vehicles with a GVWR of 16,001lbs or more must carry chains or approved alternate traction devices on newly identified Colorado Mountain Corridors. Please review the Must Carry Law Flyer for more information. 

Must Carry Law Flyer - English

Must Carry Law Flyer - Spanish

This is an expansion of the original Must Carry law on a portion of the I-70 corridor. For full law text please refer to Senate Bill 24-100

This map illustrates the routes in Colorado impacted by Colorado Senate Bill 24-100, which mandates chain requirements for commercial motor vehicles (CMVs). The bill covers seven key routes.

Truck Safety & Winter Driving in Colorado

Colorado Chain Up Tips

Truck driving up Berthoud Pass with snow road conditions.

This information applies to Colorado state, federal and interstate highways.

Colorado Chain Up Tips Flyer

Carrying Chains In Colorado

Commercial vehicles driving through Colorado on the below corridors must carry appropriate chains or approved alternative traction devices from September 1 through May 31. 

  • I-70 west of MP 259 (Morrison)
  • CO-9 MP 63 to MP 97 (Frisco to Fairplay)
  • US Route 40 west of MP 256 (Empire)
  • US Route 50 west of MP 225 (Salida)
  • US Route 160 west of MP 304 (Walsenburg)
  • US Route 285 west of MP 250 (Morrison)
  • US Route 550 from MP 0 to 130
CMV by Definition

Commercial Motor Vehicle (CMV) for purposes of these rules means a vehicle having a manufacturer's gross vehicle weight restriction (GVWR) or GCWR of at least 16,001 pounds and used in commerce on public highways, or a GVWR or GCWR of at least 16,001 pounds and used to transport at least 16 passengers, including the driver

Chain Law

To travel on a state highway when the Commercial Motor Vehicle Chain Law is in effect, a CMV must have chains or approved alternate traction devices (ATDs) on at least four of the drive wheel tires, or all of the drive wheel tires if the vehicle has fewer than four drive wheel tires. Buses are required to chain or have ATDs on two drive wheel tires.

  • CMV's required to chain 4 drive tires:
    • Straight Trucks
    • Single Drive Axle Combinations
    • Tandem Drive Axle Combinations
    • Auto Transporters 
  • CMV's required to chain 2 drive tires: 
    • Busses
    • Hot shots (pulled by a pickup truck or similar meeting the 16,001 lb or more weight requirement for carrying chains)
Chain Law Notifications

The applicable traction and chain law requirements will be messaged out through the CDOT notification process, including Variable Message Signs, static signs, other official traffic control devices as appropriate, the CDOT travel website, telephonic messaging system, email, text notifications, and other technologies. Notifications will specify by mile points and by exit number when chains are required.

Chaining Up

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).

Tire Chains

Tire chains include but are not limited to metal chains which consist of two circular hoops, one on each side of the tire, connected by not less than nine evenly spaced chains across the tire tread. Tire chains shall meet the SAE classification as by the National Association of Chain Manufacturers. Clip-on chains are not permitted, nor is any other device not designated as an approved ATD.

Tire Cables

Tire cables are traction devices made of steel cable as opposed to steel chain link, which has high strength steel cross member rollers 0.415" or greater in diameter. 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 and tire cables cannot be used together.

Alternative Traction Devices

Alternative Traction Devices (ATD) must be one of the ATD included in the CDOT Approved Product List (APL). Drive wheel sanders and pneumatically driven chains are also allowed.

Passing Requirements When Chain Law is Active

CMVs shall be restricted to the right lane unless encountering a stalled or slower moving vehicle that would result in the loss of traction, in which case the CMV may utilize the left or center lane to pass if the movement can be made safely and without interference with other traffic. Any such pass must be completed without losing traction and the CMV must return immediately to the right lane upon completion of the pass.

Frequently Asked Questions (FAQ)

Are chains required for trailers?

No

Must hazardous material tankers and transporters comply with the chain law?

Yes. Vehicles placarded for hazardous loads may pass the chain up signs, and install chains where pavement is covered by snow or ice at a safe location outside the traveled portion of the highway.

When can chains be removed?

The Chain Law shall remain in effect until either notice is communicated to the traveling public by Variable Message Signs (VMS), static sign or other CDOT notification, or when the centerline or lanes are visible on a descending grade.

Where are chain up stations?

COTrip Map of Chain and Brake Check Stations

RoadwayNameDirectionMP
I-70LIMON WEST CHAIN STATION MP-358WB358
I-70AGATE CHAIN STATION MP-340EB340
I-70AURORA WESTBOUND CHAIN STATION MP-290WB290
I-70AURORA EASTBOUND CHAIN STATION MP-290EB290
I-70LAKEWOOD CHAIN STATION MP-263WB263
I-70GENESEE PARK CHAIN-UP STATION MP-253WB253
I-70GENESEE PARK CHAIN-UP STATION MP-253EB253
I-70EL RANCHO CHAIN STATION MP-250EB250
I-70IDAHO SPRINGS CHAIN STATION MP-241EB241
I-70GEORGETOWN WB CHAIN STATION MP-228WB228
I-70GEORGETOWN EB CHAIN STATION MP-228EB228
I-70BAKERSVILLE WB CHAIN STATION MP-220WB220
I-70HERMAN GULTCH WB CHAIN STATION MP-219WB219
I-70HERMAN GULTCH EB CHAIN STATION MP-219EB219
I-70DILLON CHAIN EB CHAIN STATION MP-205EB205
I-70FRISCO EB CHAIN STATION MP-203EB203
I-70FRISCO WB CHIAN STATION MP 202WB202
I-70COPPER MTN WB CHAIN STATION MP 195WB195
I-70COPPER MTN EB CHAIN STATION MP 195EB195
I-70VAIL PASS EB CHAIN STATION MP 185EB185
I-70VAIL PASS WB CHAIN STATION MP 182WB182
I-70VAIL WB CHAIN STATION MP 178WB178
I-70VAIL EB CHAIN STATION MP 178EB178
US-40STEAMBOAT SPRINGS WB CHAIN STATION MP 139WB139
US-40STEAMBOAT SPRINGS EB CHAIN STATION MP 139EB139
US-40KREMMLING WB CHAIN STATION MP 159WB159
US-6A-BASIN EB CHAIN STATION MP 219EB219
US-285KENOSHA PASS WB CHAIN STATION MP 209WB209
US-550OURAY NB CHAIN STATION MP 95NB95
US-550SILVERTON NB CHAIN STATION MP 71NB71
US-550SILVERTON SB CHAIN STATION MP 69SB69
US-550PURGATORY DURANGO SB CHAIN STATION MP 49SB49
US-550PURGATORY DURANGO NB CHAIN STATION MP 49NB49
US-550DURANGO NB CHAIN STATION MP 38NB38
US-550HERMOSA NB CHAIN STATION MP 34NB34
US-160DURANGO WB CHAIN STATION MP 77WB77
US-160PAGOSA SPRINGS EB CHAIN STATION MP 157EB157
US-160WOLF CREEK PASS WB CHAIN STATION MP 173WB173
US-160WOLF CREEK PASS EB CHAIN STATION MP 173EB173
US-160SOUTH FORK EB CHAIN STATION MP 176EB176
US-160NORTHERNMOST SOUTH FORK WB CHAIN STATION MP 176 WB176
US-160FORT GARLAND EB CHAIN STATION MP 261EB261
US-160FORT GARLAND WB CHAIN STATION MP 261WB261
US-160GARDNER EB CHAIN STATION MP 276EB276
US-160MULESHOE WB CHAIN STATION MP 281WB281
US-285PONCHA SPRINGS NORTHERNMOST SB CHAIN STATION MP 125SB125
US-285PONCHA PASS NB CHAIN STATION MP 119NB119
US-285PONCHA PASS SB CHAIN STATION 119SB119
US-50MONARCH PASS EB CHAIN STATION MP 209EB209
US-50MONARCH PASS WB CHAIN STATION MP 209WB209
US-50GARFIELD WB CHAIN STATION MP 204WB204
US-50SARGENTS WB CHAIN STATION MP 190WB190
US-50SARGENTS EB CHAIN STATION MP 190EB190
I-25TRINIDAD SB CHAIN STATION MP 11SB11
I-25BAPTIST ROAD NB CHAIN STATION MP 158NB158
I-25LARKSPUR REST AREA (CLOSED) NB CHAIN STATION MP 170NB170
I-25LARKSPUR REST AREA (CLOSED) SB CHAIN STATION MP 170SB170
CO-13RIFLE NB CHAIN STATION MP 12NB12
What are the fines for violations?

Penalty for not carrying chains on the below Interstate and Highway corridors from Sept. 1 - May 31 is a $100+ fine plus a $17 surcharge.

  • I-70 west of MP 259 (Morrison)
  • CO-9 MP 63 to MP 97 (Frisco to Fairplay)
  • US Route 40 west of MP 256 (Empire)
  • US Route 50 west of MP 225 (Salida)
  • US Route 160 west of MP 304 (Walsenburg)
  • US Route 285 west of MP 250 (Morrison)
  • US Route 550 from MP 0 to 130

Statewide, the penalty for noncompliance with winter driving restrictions: up to $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.