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Chain-Up Laws for Colorado Winter Driving

Colorado's winter weather can bring dangerous road conditions, especially through mountainous areas like the I-70 corridor. To ensure safety for all motorists, the Colorado Department of Transportation (CDOT) enforces strict chain-up laws during snow and ice events. These laws are particularly crucial for commercial vehicle drivers but can affect all motorists, depending on road conditions.

When Chain Laws Are Active

Chain laws are activated by CDOT during adverse winter weather and are most commonly enforced on mountain passes such as Vail Pass and the Eisenhower Tunnel approach. Drivers will see electronic highway signs and receive alerts through CDOT’s COtrip system when the laws go into effect.

There are two levels of chain law enforcement:

  • Level 1: Applies to all commercial vehicles (vehicles weighing 26,001 lbs. or more) and requires them to have chains or approved alternate traction devices.
  • Level 2: Applies to all commercial vehicles and may also require passenger vehicles to have either snow tires, all-wheel drive, or chains if conditions worsen.

Vehicles Required to Chain Up

During a Level 1 chain law, only commercial vehicles must comply. At Level 2, passenger vehicles that are not equipped with adequate traction equipment (i.e., snow tires or AWD with sufficient tread) must use chains or alternative traction devices like AutoSocks.

The chain law specifically impacts:

  • Semi-trucks and large freight vehicles
  • Buses and large passenger vans
  • Passenger vehicles (under Level 2 only)

Chains must be carried on commercial vehicles from September 1 through May 31 when traveling on I-70 between Dotsero (mile marker 133) and Morrison (mile marker 259).

Equipment Requirements

Chains must meet CDOT specifications and be installed on drive wheels. For passenger vehicles, chains or approved alternate traction devices must be installed when directed by signage.

Vehicles not properly equipped can be denied access or turned around at checkpoints.

Penalties for Noncompliance

Failure to comply with the chain law in Colorado can result in steep fines:

  • $100 fine plus a $32 surcharge for not carrying chains when required.
  • $500 fine plus a $79 surcharge for not chaining up when required.
  • $1,000 fine plus a $157 surcharge if your vehicle blocks the roadway due to lack of chains or adequate traction.

For more on related traffic enforcement, see Colorado Express Lane Fines and Rules.

Safety and Compliance Tips

Drivers should:

  • Check CDOT’s chain law fact sheet for full compliance details.
  • Monitor weather conditions and CDOT alerts before travel.
  • Ensure chains or traction devices are readily available in winter months.
  • Practice installing chains before the season begins.

Failure to follow chain-up laws can lead to dangerous conditions for all road users, especially on steep inclines or sharp turns common in Colorado's high-altitude regions.

Drivers looking to prepare further for road safety should also review Colorado's Hands-Free Driving Law Explained and Rear-Facing Car Seat Law in Colorado to stay compliant with all driving regulations.

For those planning to drive during peak winter periods, consider equipping your vehicle early and staying up-to-date with all safety and legal requirements through official sources and updated driver’s license eligibility guidelines.