All-Season Tires
The all-season designation was derived from tread designs when tires transitioned from bias-ply to radial tires. These tires are suitable for driving on roads on a year-round basis. Unfortunately all-season tires provide little traction advantage in winter driving conditions.
M+S Designated Tires
The M+S tire designation is based on the geometry of the tread design. The M+S designation was first used to differentiate the knobby bias ply tires intended for use on muddy, and/or snow-covered roads from the straight rib tires used on early cars or trucks. Tires with tread designs that meet this definition may be branded with the letters “M” and “S” in several different ways (e.g., M&S, M+S, M/S, MS, etc.) at the discretion of the tire manufacturer. However, various alternatives to studded tires are now available to motorists for improving traction on winter driving surfaces.
Studless Winter Tires
Studless winter tires (typically Q-rated with a mountain-snowflake symbol shown) are now available to motorists as a substitute for studded tires. These tires have tire tread composed of special rubber compounds and tread designs that enhance their performance in snow and ice conditions. According to a 1997 study by TranSafety, Inc, an independent source for publications and information on road transportation and safety, “the State of Alaska tested Bridgestone’s Blizzak tire and found it offers an acceptable substitute to the pavement-destroying studded tire.”
Innovative tires
The Green Diamond Tyre Company of Iceland has developed an alternative to the studded tire in which hard granules are distributed evenly on the wear-surface of the tire. Toyo manufactures a tire with crushed walnut in the rubber. Goodyear layers an ice traction tread compound (enhanced with silica and specialized polymers) in its tires. These tires provide better traction in slippery conditions without the road wear and noise emission of studded tires. Actual on-ice testing of some of the tires show that they perform better than studded tires.
Tire chains
Tire chains have always been a functional alternative to motorists needing traction on compact snow. Operated at relatively low speeds, tire chains offer reliable performance benefits for motorists including traction on icy or snow packed roads and other special use conditions where ‘snow bottom’ roadways are present. On the other hand, as driving conditions change, WSDOT recommends immediately removing tire chains since they are capable of imposing major damage to bare, wet, and even sanded roadways. Tire chains are often the only alternative for motorists in areas where heavy winter driving conditions are the norm.
Lightweight studs
In addition to the studless winter tires, motorists can still use lightweight studs for their traction needs. Since July 1, 2001, Washington retailers can only install lightweight studs in tires that meet new legal requirements established under Title 46 RCW ‘Motor Vehicle,’ Chapter 46.04. Your local tire retailer has information on fitting your vehicle with the appropriate lightweight tire studs based on your vehicle’s tire size.
Manufacturers claim that lightweight studs do 15% less damage than regular steel studs. Lightweight studs wear and operate equally as well as regular steel studs and will not compromise safety on icy roads. Further studies show that the use of lightweight studs could cut the yearly damage proportionately without compromising any performance characteristics. Lightweight studs are now being used successfully in the State of Oregon and have the support of the Northwest Tire Dealers Association.