Fact Sheet -Traction Law and Passenger Vehicle Chain Law

Traction Law (Code 15) - Use George's Head to Check Your Tread

  • If weather conditions require, CDOT will implement a Traction Law.
  • Under a Traction Law, motorists will need to have either snow tires, tires with the mud/snow (M+S) designation, or a four-wheel/all-wheel drive vehicle - all tires must have a minimum one-eighth inch tread.

Passenger Vehicle Chain Law (Code 16) - Chain Up or Stay Off

  • During severe winter storms, CDOT will implement a Passenger Vehicle Chain Law - this is the final safety measure before the highway is closed.
  • Under a Passenger Vehicle Chain Law, every vehicle on the roadway is required to have chains or an alternative traction device (like AutoSock).


  • Motorists driving with inadequate equipment during a Traction Law or Passenger Vehicle Chain Law could be fined more than $130.
  • If a motorist blocks the roadway because they have inadequate equipment during a Traction Law or Passenger Vehicle Chain Law, they could be fined more than $650.

Test Your Tread

Find out if your tires are safe for winter driving by doing the Quarter Test:

  • Insert a quarter upside down into your tire tread, with Washington's head going in first.
  • If the top of the head is covered by tread, you're good to go.
  • If the top of his head is visible at any point around the tire (test multiple points), you can't drive when a Traction Law is called - you also likely need new tires.

Traffic Facts

  • At 60 MPH on snowy pavement, winter tires require 310 ft. to stop. All-season tires require more than double that (668 ft.).
  • In 2014, one of the worst traffic delays on the I-70 Mountain Corridor was caused by unprepared motorists. Severe delays were caused by 22 vehicles spinning out and causing crashes - 19 of those vehicles had worn tires.
  • Traffic accidents - not volume - account for as much as 60 percent of all traffic delays.
  • A crash that only takes 10 minutes to clear can delay traffic for an hour.

Statewide Tire Deals

  • To help motorists prepare for winter driving, CDOT has partnered with tire companies across the state to offer discounts on new tires.
  • To find a tire company with deals near you, visit winter.codot.gov/tires.

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