Do I need tire chains in Colorado?

With I-70 as Colorado's main corridor that runs east and west across the Rockies there are a few things all travelers in Colorado need to know.

All commercial vehicles must carry chains from September 1st to May 31st. 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.

https://csp.colorado.gov/chain-law-information

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.

From Colorado State Patrol

Truck Safety Campaign

Terms and conditions may apply. Offer expires 5/31/2026. [More details]

Chains can make the difference

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)(opens in new window), phone message system, email, text and other automated personal notification systems.

Tire chains to the rescue

A set of chains on your drive axle can provide the extra traction needed to make it up the hill. Slipping, sliding, and losing momentum with no tire chains on your way up the pass is a sure way to get noticed. If you get stuck on I-70 and you are holding up traffic that is just the beginning of a bad day. A tow truck or two will be your next view as they drag you to safety. Then Colorado State Patrol will probably write you a ticket with a variety of violations listed on it. There is a better way, have tire chains ready.
Need to stop on an icy road - pewag can help

pewag tire chains can make the difference. The extra traction tire chains provide can help you stop in time and avoid costly repairs or even a serious accident. Sometimes things just happen and you have to stop or slow down quickly. You can't control every scenario out there on the road and stopping suddenly can sometimes save a lot damage.
Who is pewag

Over-the-road truckers, oilfield haulers, logging rigs, utility fleets, and trailer operators rely on pewag—the premium solution for premium fleets—traction chains that outlast the competition, getting them through winter storms and highway snow on time. Known for premium long-lasting square link chains, we're also the only company offering made-in-USA studded chains.
There is documentation dating back to 1479 that a forging plant in Brückl Austria was the beginning of what was to become the pewag group that we know today. Fast forward to 1912 and pewag produces its first Snow Chain. 1975 comes around and the US gets a pewag sales company which has evolved to provide the quality tire chains that we offer today.
Passenger Vehicles as well in certain cases.

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. See CSP for more information