A Simplified Procedure for Computing Vehicle Offtracking on Curves

The report presents a simplified procedure for computing vehicle offtracking on curves. It was developed during a research effort to determine what the offtracking requirements were if the width of buses for operation on the Interstate Highway System was increased from 96 to 102 inches. The procedure was developed by modifying the existing procedures to identify critical bus offtracking. Modification consisted of the use of an additional geometric relationship required to calculate 'swept width', a parameter considered to be more significant than 'offtracking' , per se. Swept width is not a problem for buses using the through traffic lanes on the Interstate Highway System, because curves as sharp as 27 degrees occur only on ramps designed for low speed and one-lane operation. The procedure developed can be used by highway design personnel to select a maximum degree of curvature which would permit a vehicle to stay within the selected lane width and by regulatory agencies when permits are requested for movement of vehicles that exceed the legal maximum width, length or both.

Media Info

  • Media Type: Digital/other
  • Pagination: 28 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00057025
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA-RD-74- 8 Final Rpt., FCP 31J3-012
  • Created Date: Jul 22 1976 12:00AM