NTL Record

Title A Simplified Procedure for Computing Vehicle Offtracking on Curves
Record ID 47952
Personal Name
Creator
Pilkington, J. B., II; Howell, P. D.
Corporate Creator United States. Federal Highway Administration. Office of Operations Research and Development
Corporate
Contributor
United States. Federal Highway Administration
Publisher United States. Federal Highway Administration
Publication Date 19731201
Language English
Abstract This 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 the apparent width of a vehicle as it executes a turning maneuver. The basic data for 15 buses and three tractor-semitrailer combinations, with widths of 96 and 102 inches, and full-sized station wagon were analyzed. Results of this analysis revealed that critical swept width does not occur until 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.
Rosap ID dot:36579
Rosap URL https://rosap.ntl.bts.gov/view/dot/36579
TRT Terms Effective stress; Wheel base; Offtracking; Axle loads; Width; Highway curves; Turning radius
General Subjects Highways; Motor Carriers; Vehicles and Equipment; I91: Vehicle Design and Safety; Turning movements
Geographical
Coverage
United States
TRIS Online
Accession No
57025
Report Number FHWA-RD-74-8, FCP 31J3-012
Resource type Tech Report
URL https://ntlrepository.blob.core.windows.net/lib/47000/47900/47952/FHWA-RD-74-08.pdf
Format PDF
Database NTL Digital Repository