(a) Alternative Traction Device (ATD) is a tire traction device which differs from tire chains in construction, design, or material. The ATD is capable of providing traction equal to or exceeding the performance of tire chains or tire cables under similar conditions. Examples of ATDs include, but are not limited to: automatic tire chains, textile traction devices, and wheel-hub attached chains, provided they meet or exceed the regulatory standards for tire chains or tire cables as provided by this article.

(b) Automatic tire chain is a device, not directly mounted on a tire, which a driver may manually activate using a switch from inside the vehicle to automatically position a strand of chain between the tire and roadway. These devices may also be referred to as “on-demand” chains.

(c) Official traffic control device shall have the same meaning as Vehicle Code Section 440.

(d) Snow-tread tires, commonly referred to as mud and snow tires, are pneumatic tires which have a relatively deep and aggressive tread pattern compared with conventional passenger tread pattern. Snow-tread tires may be identified using the following manufacturer markings appearing on the tire sidewall as follows: “MS,” “M-S,” “M/S,” “M+S,” any contraction using the letters “M” and “S,” the words “MUD AND SNOW,” or a “Mountain/Snowflake” (Figure 1) symbol.

(e) Studded tires are pneumatic tires containing metal-type studs of tungsten carbide or other suitable material which are embedded into the surface of the tire to improve traction on snowy or icy roads. Studded tires shall comply with Vehicle Code Section 27454.

(f) Textile traction devices are constructed of a fabric weave covering which is installed over the tire and provides additional traction material to the tread area of the tire.

(g) Tire cables are steel cables which have high strength steel cross member rollers which are evenly spaced to cover the surface area of the tire. These devices may also be referred to as “cable chains.”

(h) Tire chains are metal chains constructed of two circular metal chain loops, one on each side of the tire, connected by metal chains across the tire, which are evenly spaced except in the area where the chain loops are fastened and adjusted. These devices may also be referred to as “traditional,” “link-type,” “ladder-type,” or welded metal chains.

(i) Tire Traction Devices are ATDs, automatic tire chains, textile traction devices, tire cables, tire chains, and wheel-hub attached chains. Snow-tread tires and studded tires are not tire traction devices as defined in Vehicle Code Section 605.

(j) Wheel-hub attached chains are constructed so that the device is secured to the outer wheel-rim of a vehicle using plastic or metal components which positions the chain between the tire and the roadway.