A STUDY OF VARIABLES ASSOCIATED WITH WHEEL SPIN-DOWN AND HYDROPLANING

VEHICLES OPERATING ON WET PAVEMENTS SUFFER IMPAIRMENT OF THEIR STEERING AND BRAKING CAPABILITIES. TESTS HAVE SHOWN THAT THIS CONDITION WORSENS AS THE VEHICLE SPEED INCREASES, AND THAT AT A CRITICAL GROUND SPEED THE VEHICULAR WHEEL IS SEPARATED FROM THE PAVEMENT BY A LAYER OF FLUID. THIS IS SAID TO BE HYDROPLANING. WHEN THIS OCCURS THE STEERING ABILITY OF THE VEHICLE IS COMPLETELY LOST, AND THE BRAKING CAPABILITY IS GREATLY DIMINISHED. THE SPIN-DOWN (REDUCTION IN WHEEL SPEED) OF A WHEEL IS AND INDICATION OF A LOSS IN THE TIRE-GROUND FRICTIONAL FORCE AND IS REGARDED BY RESEARCHERS AS A MANIFESTATION OF HYDROPLANING. SPIN-DOWN OCCURS WHEN THE HYDRODYNAMIC LIFT EFFECTS COMBINE TO CAUSE A MOMENT THAT OPPOSES THE NORMAL ROLLING ACTION OF THE TIRE CAUSED BY THE DRAG FORCES. AS GROUND SPEED INCREASES, THE TIRE BECOMES DETACHED FROM THE PAVEMENT, WHICH DECREASES THE GROUND FRICTION ON THE TIRE. ALSO AS GROUND SPEED INCREASES, THE CENTER OF HYDRODYNAMIC UPLIFT FORCES MOVES FORWARD OF THE AXLE, WHICH CAUSES A MOMENT THAT OPPOSES THE DRAG FORCES ON THE TIRE; AS THIS MOMENT INCREASES, SPIN-DOWN BEGINS. THIS REPORT USES WHEEL SPIN-DOWN AS A CRITERION FOR EVALUATIONG THE WET-WEATHER PROPERTIES OF A PORTLAND CEMENT CONCRETE PAVEMENT AND A BITUMINOUS SURFACE, AND CONSIDERS THE EFFECTS OF WATER DEPTH, TIRE INFLATION PRESSURE, TIRE TREAD DEPTH, AND WHEEL LOAD. THE STUDY WAS PERFORMED BY CONDUCTING FULL-SCALE TESTS ON A HYDROPLANING TROUGH 800 FT LONG, 30 IN. WIDE AND 4 IN. DEEP. WATER DEPTHS UP TO 0.8 IN. CAN BE MAINTAINED IN THE TROUGH. /AUTHOR/

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrr/1972/396/396-004.pdf
• Supplemental Notes:
  • Sponsored by Committee on Surface Properties-Vehicle Interaction. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • MARTINEZ, J E
  • Lewis, J M
  • Stocker, A J
• Conference:
  • 51st Annual Meeting of the Highway Research Board
  • Location: Washington District of Columbia, United States
  • Date: 1972-1-17 to 1972-1-21
• Publication Date: 1972

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: pp 33-44
• Monograph Title: Pavement friction characteristics and water depths
• Serial:
  • Highway Research Record
  • Issue Number: 396
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Bituminous pavements; Braking; Hydroplaning; Moisture content; Pavement performance; Portland cement concrete; Speed; Steering; Tire treads; Wheel loads
• Uncontrolled Terms: Wet conditions
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00221822
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Feb 23 1973 12:00AM