EVALUATION OF WINTER VEHICLE TRACTION WITH DIFFERENT TYPES OF TIRES

Studded tires have been used during winter to increase vehicle traction force for reasons of safety. Past experience and factual data have shown that the problems of accelerated pavement wear and airborne dust have been caused by the use of studded tires. The use of studded tires has been prohibited in some countries and in some states in the United States. Recently, the Bridgestone Tire Company designed and examined a new type of tire, called the Blizzak, to improve winter vehicle traction and minimize pavement wear. To adopt this new type of tire in Alaska, the Alaska Department of Transportation and Public Facilities conducted a preliminary field study to compare the new tires with the studded tires in terms of stopping distance on packed snow and icy surfaces in Fairbanks and Anchorage in January 1994. More comparative tests of the Blizzaks, studded tires, and all-season tires were conducted in March 1994 by the University of Alaska in Fairbanks and Anchorage. The vehicles used in these tests were mid-size front-wheel-drive cars, large rear-wheel-drive cars, and half-ton full-size rear-wheel-drive pickup trucks. Field tests included 40.3-km/hr (25-mph) stopping distances, starting traction and times to reach 40.3 km/hr (25 mph), maximum cornering speeds on short-radius curves typical of intersections, and hill climbing ability. From field test results, it was concluded that Blizzaks may be used during winter to replace studded tires in Alaska.