ARE CALCULATIONS FOR MODIFIED COEFFICIENT OF FRICTION ACCURATE?

This note aims to establish the accuracy of practical applications of a simple formula for converting coefficient of friction between uphill and downhill, to uphill and downhill skid testing. An experiment was conducted at Mill Road, Brighton, England, which provided a suitable test site. Mill Road is a three-lane carriageway rising up the side of the South Downs, and is travelled by all classes of vehicles. The lanes are downhill, centre, and uphill. Three tests were conducted on each lane and in both directions. The gradient was about 4%. A procedure is given for calculating the percentage difference, and providing the widest possible range from the tests and calculated results. A numerical example shows that, in the velocity calculation, even using the widest range, the results showed a variation within 3% of each other, well within the 1% confidence range usually quoted for this type of calculation. The test results indicate that it is valid to apply the current simple formula for modifying the coefficient of friction, not only in theoretical physics, but also in a practical application. Traffic polishing in a particular direction was not found to have any significant effect.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09594302
• Corporate Authors:

  METROPOLITAN POLICE FORENSIC SCIENCES LABORATORY

  109 LAMBETH ROAD
  LONDON,   United Kingdom  SE1 7LP
• Authors:
  • LABBETT, S
• Publication Date: 1997

Language

• English

Media Info

• Pagination: p. 10-11
• Serial:
  • IMPACT (ITA1)
  • Volume: 6
  • Issue Number: 1
  • Publisher: METROPOLITAN POLICE FORENSIC SCIENCES LABORATORY
  • ISSN: 0959-4302

Subject/Index Terms

• TRT Terms: Calculation; Coefficient of friction; Directional distribution; Highway grades; Mathematical models; Polished aggregates; Skidding; Slopes; Speed; Test procedures; Traffic lanes; Types of traffic; Velocity
• Uncontrolled Terms: Traffic direction
• Geographic Terms: United Kingdom
• ITRD Terms: 6464: Calculation; 2992: Carriageway; 5460: Coefficient of friction; 626: Direction (traffic); 2806: Gradient; 6473: Mathematical model; 3822: Polishing; 1645: Skidding; 5408: Speed; 6288: Test method; 8119: United Kingdom
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00738330
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Jul 30 1997 12:00AM