DENVER (CBS4) – Winter driving season is here in Colorado’s high country. In fact, you’ve probably seen the CDOT signs telling commercial vehicles to carry chains along Interstate 70. We’ll likely see numerous chain and traction laws issued for main mountain highways between now and next spring.

(credit: CBS)

What exactly is a traction law? A traction law is issued for all motorists when road conditions warrant specific devices or adequate tires to ensure safe travel. They are usually activate during a winter storm, but sometimes they can be implemented in windy situations, when old snow from a previous storm is being blown onto a highway. We see this a lot along Highway 285 between Kenosha Pass and Fairplay each winter season.

Traction laws focus on passenger vehicles traveling through the mountains of Colorado. During a traction law you are required to have one of the following…

  • a 4WD or AWD vehicle with at least 3/16″ tread depth
  • tires with a mud or snow designation (M+S Icon) and 3/16″ tread depth
  • winter tires (mountain-snowflake icon) and 3/16″ tread depth
  • tires with an all-weather rating by the manufacturer and 3/16″ tread depth
  • chains or an approved alternative traction device

(credit: CBS)

What are chain laws? A chain law means a vehicle must have chains or an alternative traction device on the tires. They are geared toward commercial vehicles, but during severe winter storms, chain laws can be extended to passenger vehicles as well. The extension to passenger vehicles is the last step before a highway is closed.

When a chain law is in effect it applies to all state, federal and interstate highways in Colorado. A vehicle is considered a commercial vehicle if it 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

Interstate 70 in the high country Wednesday morning (credit: CBS)

Motorists caught with inadequate equipment during a chain or traction law could face a fine in excess of $130. If a motorist blocks a roadway during a chain or traction law because they lack the proper equipment, he or she could face a fine of more than $650.

For Interstate 70 specifically, between Dotsero and Morrison, between the dates of September 1 and May 31, all commercial vehicles are required to carry sufficient chains or alternative traction devices. It can be a very expensive lesson if caught driving along I-70 without them during an active chain law.

  • if caught without chains when a chain law is in effect the driver will face a $50 fine plus a $17 surcharge
  • if caught not chaining up during an active chain law a commercial vehicle driver will face a $500 fine plus a $79 surcharge
  • if caught blocking the highway as a result of not chaining up a commercial vehicle driver will face a $1,000 fine plus a $157 surcharge

This story was originally published on in October 2021.

Chris Spears