Friction tests of Studded Tires in Snow and Ice

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MSI
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Friction tests of Studded Tires in Snow and Ice

Post by MSI »

Q: Are there any published tests of studded tires on snow and ice?

A: In addition to what is contained in our previous topic on Friction Variation in cooler temperatures the following are some tests specifically on studded tire testing:
AN OVERVIEW OF STUDDED AND STUDLESS TIRE TRACTION AND SAFETY
  • Washington State Transportation Center (TRAC)
    • Studded tires have generated much controversy over the years; a number of states have banned them, while others, including Washington, have restricted their use and passed legislation to require lighter-weight studs. This report reviews recent studies that have addressed the performance and safety of the current generation of studded tires as well as the new “studless” winter tires on late-model vehicles.
      The well-documented correlation between studded tires and pavement wear was not the focus of this work.
      The issues surrounding studded tire performance and safety are complex. From the standpoint of traction
      alone, studded tires, when new, often provide some benefit over other tire types on ice-covered roads when the temperature is near freezing. However, the advent of the new studless tires has diminished the marginal benefit, and recent studies suggest that the infrequent, narrow range of conditions necessary
      for benefit from studded tires may not outweigh their detrimental effect on traction in dry or wet conditions on certain pavement types. In addition, a host of primary and secondary safety factors are related to studded tire use, many of which are very difficult to quantify, including facets of driver behavior and safety perception
Winter Vehicle Traction and Controllability Performance
  • Jian John Lu, Institue of Northern Engineering, 1994
    • In Alaska, studded tires have been used during the winter season to increase vehicle traction force for safety reasons. Past experience and tactual data have shown that the problems of accelerated pavement wear and airborne dust have been caused by the use of studded tires. Use of studded tires has been prohibited in many countries. Recently, the Bridgestone Tire Company designed and examined a new type of studless winter tire under the "Biizzak" brand name to improve winter vehicle traction and minimize pavement wear. In order to evaluate this new type of tire, the Alaska Department of Transportation and, Public Facilities conducted a preliminary field study in January of 1994 to compare the new tires with studded tires in stopping distance tests on packed snow and icy surfaces in Fairbanks and Anchorage. To verify and extend these results, more comparative tests of the Blizzaks, studded tires, and all-season tires were conducted in March and April of 1994 by the University of Alaska at locations in Fairbanks and Anchorage. The vehicles used in these tests were mid-sized front wheel drive cars, large rear wheel drive cars, and half-ton full size rear wheel drive pickup trucks. The purpose of these tests was to evaluate the differences between these tire types. Field tests included 25 mph, maximum cornering speeds on short radius curves typical of intersections and hill climbing ability. From field tests results, the new studless tires were proven superior to all-season tires under all conditions. On icy surfaces, the Blizzaks and studded tires showed almost the same performance on cornering speed in different curves, and in hill climbing ability. However, on ice surfaces, the Blizzaks had 25 mph stopping (distances, which were greater by about 8-10% (than those of studded tires) as well as longer times to reach 25 mph by about 12-15%. In summary, the Blizzaks may be used during the winter season as the best alternative to replacing the studded tires commonly used in Alaska.
STUDDED TIRES - SKID RESISTANCE AND PAVEMENT DAMAGE
  • 1966, Burnett, W B & Kearney, E J
    • STUDDED SNOW TIRES WERE INTRODUCED BY TIRE MANUFACTURERS IN 1964 TO PROVIDE INCREASED SKID RESISTANCE AND TRACTION ON ICE AND PACKED SNOW. A TYPICAL STUD CONSISTS OF A 3/32-IN. DIAMETER TUNGSTEN CARBIDE CORE PROTRUDING 1/16 IN. FROM A 3/16-IN. DIAMETER STEEL SHEATH WHICH FITS VERY TIGHTLY IN HOLES FORMED IN THE TREAD. THIS INVESTIGATION WAS PERFORMED TO DETERMINE IF STUDDED TIRES WOULD BE MORE SLIPPERY THAN REGULAR SNOW TREADS ON WET OR DRY PAVEMENTS, AND TO EXAMINE THE EFFECT OF STUDS ON SKID RESISTANCE ON ICE AND PACKED SNOW. IN ADDITION, INFORMATION WAS DESIRED CONCERNING PAVEMENT DAMAGE WHICH MIGHT BE CAUSED BY STUDDED TIRES. A STUDDED SNOW TIRE AND AN IDENTICAL SNOW TIRE WITHOUT STUDS WERE PURCHASED. THE TIRES /7.75X14/ WERE MADE BY A MAJOR MANUFACTURER, AND ONE CONTAINED ABOUT 70 STUDS, 6 OF WHICH CONTACTED THE ROAD SURFACE AT ANY ONE TIME. THESE TIRES WERE MOUNTED ON THE DEPARTMENT SKID TEST TRAILER. TESTS WERE PER- FORMED BY LOCKING A TRAILER WHEEL AND SLIDING THE TEST TIRE AT A CONSTANT SPEED OF 30 MPH. OVER 100 TESTS WERE PERFORMED WITH THE STUDDED TIRE ON ICE AND SNOW AND ON WET AND DRY BI- TUMINOUS AND CONCRETE PAVEMENTS. AFTER EACH TEST THE ROAD SURFACE WAS EXAMINED FOR DAMAGE. THE STUDDED AND UNSTUDDED TIRES PROVIDED APPROXIMATELY THE SAME AMOUNT OF SKID RESISTANCE ON BARE PAVEMENTS, EITHER WT OR DRY, AT 30 MPH. AT THIS SPEED THE STUDDED TIRE INCREASED SKID RESISTANCE ON ICE ABOUT 40 PERCENT AND ON PACKED SNOW ABOUT 9 PERCENT. THE PAVEMENT DAMAGE CAUSED BY THE SLIDING STUDDED TIRE WAS NOT CONSIDERED SIGNIFICANT. HOWEVER, IT WAS NOT POSSIBLE TO OBTAIN AN INDICATION OF PAVEMENT WEAR THAT MIGHT RESULT FROM EXTENSIVE USE OF STUDDED TIRES ON HIGHWAYS CARRYING LARGE VOLUMES OF TRAFFIC.