Colorado’s Chain Law

It’s no secret that Colorado’s mountains can get icy and dangerous during the winter season. That’s why it’s important to understand and adhere to Colorado’s Chain Law. This law was enacted in 1996 to try and keep drivers safe on all state, federal, and interstate highways. Snow chains help vehicles drive across the steep climbs that are commonly found in the high country.

Chain Laws

The law states that from September 1 to May 31, all commercial vehicles must carry sufficient chains with them when traveling on I-70. These are required between the Dotsero exit at mile point 133 and the Morrison exit at mile point 259. There are two levels of chain law that apply to commercial vehicles:

  • Chain Law Level 1: All single drive axle combinations commercial vehicles are required to chain up all four wheels. All other commercial vehicles must have either snow tires or chains. Cables are not permitted as an alternative to the chains. This level may be implemented any time if there is snow on any part of the traveled portion of pavement on an ascending grade.
  • Chain Law Level 2: All commercial vehicles are required to chain up if there is snow covering the entire traveled portion of pavement on an ascending grade or whenever weather and driving conditions call for this level to protect drivers and minimize closures. Buses are also required to chain two drive wheels.

What’s a Commercial Vehicle?

A commercial vehicle is different than a personal vehicle. It is used in commerce to transport passengers or property. According to the Colorado Department of Transportation (CDOT), a commercial vehicle fits into any of the following categories:

  • Gross combination weight rating of 16,001 or more pounds, inclusive of a towed unit, which has a gross vehicle weight-ration of more than 10,000 pounds
  • Gross vehicle weight rating of 16,001 or more pounds
  • Designed to transport 16 or more passengers, including the driver

There are also non-commercial vehicles that the chain law restricts any time the weather conditions are severe enough. These vehicles include passenger vehicles, crossovers, SUVs, and small trucks.

Specific Codes

Along with these general rules regarding the chain law, there are also specific codes to be aware of according to CDOT:

  • Code 18 – Commercial Chain Law: commercial vehicles and trucks must have chains
  • Code 15 – Passenger Traction Law: all motorists are required to either have an all-wheel or four-wheel drive vehicle, or snow tires or all-weather tires with a mud/snow designation for two-wheel drive vehicles.
  • Code 16 – Passenger Chain Law: all passenger vehicles need chains, except for 4WD and AWD vehicles with all-weather tires with a 3/16-inch tread depth

While you’re preparing for the winter weather, be sure to bring your vehicle, commercial or personal, into Houska. We’ll make sure it’s ready to handle the Colorado winter.

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