CDOT has approved the AutoSock as the only named alternative traction device to chains that is accepted within the state. For more information, check out their site: Passenger or Truck
Alternate Traction Devices (ATDs)
Approved ATDs in Colorado are wheel sanders, which carry enough sand to get the vehicle through the restricted area; pnuematically driven chains, which spin under the drive wheels automatically as traction is lost; and textile traction device (TTD), a fabric boot which encompasses the tire. Currently, the only TTD that has been approved for use on Colorado state highways is the AutoSock. TM
Colorado’s chain law was enacted in 1996. It applies to all interstate, federal and state highways. It includes two levels for commercial vehicles:
- Chain Law Level 1 requires all single drive axle combinations commercial vehicles to chain up. All four drive wheels must be chained; cables are not permitted as an alternate traction device. All other commercial vehicles must have snow tires or chains. Level 1 may be implemented any time there is snow covering any part of the traveled portion of pavement on an ascending grade.
- Chain Law Level 2 requires all commercial vehicles to chain up. Auto transports must comply to the extent possible without causing damage to hydraulic lines. Buses must chain two drive wheels to comply. Level 2 may be implemented any time there is snow covering the entire traveled portion of pavement on an ascending grade or when driving conditions dictate this level is necessary to protect safety and minimize closures.
The alternate traction control device known as the AutoSock™ remains an approved device in Colorado. Commercial vehicles (both single and double-axle) exceeding 26,000 Gross Vehicle Weight or vehicles carrying 16 passengers or more have the option of using AutoSock™ rather than chains. This traction control device is a fabric that slips over a vehicle’s outer driving wheels, providing extra traction on snowy and icy roads. It also can be installed over the tire in less time than traditional chains.