ON THE CALCULATION OF INTERNATIONAL ROUGHNESS INDEX FROM LONGITUDINAL ROAD PROFILE

The international roughness index (IRI) was established in 1986 by the World Bank and based on earlier work performed for NCHRP. IRI is calculated from a measured longitudinal road profile by accumulating the output from a quarter-car model and dividing by the profile length to yield a summary roughness index with units of slope. Although IRI is used widely, there is no single, short reference document that describes what it is and how it is calculated. Instead, the critical information is spread over several large reports. A short, self-contained reference that defines IRI is provided, along with all the information needed to compute it from longitudinal road profile measurements. The development of the IRI is reviewed, the mathematical definition is presented, an algorithm for calculating IRI is derived, the performance of the algorithm is analyzed, tested Fortran source code for computing IRI is presented, and problems with IRI (and profile measurement in general) that have emerged since 1986 are identified.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1995/1501/1501-001.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=ON+THE+CALCULATION+OF+INTERNATIONAL+ROUGHNESS+INDEX+FROM+LONGITUDINAL+ROAD+PROFILE&author=M.+Sayers&publication_year=1995
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03611981
• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1501, Pavement-Vehicle Interaction and Traffic Monitoring. 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:
  • Sayers, Michael W
• Publication Date: 1995

Language

• English

Media Info

• Features: Figures; References;
• Pagination: p. 1-12
• Monograph Title: Pavement-vehicle interaction and traffic monitoring
• Serial:
  • Transportation Research Record
  • Issue Number: 1501
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Algorithms; Calculation; Definitions; Development; Problem identification
• Identifier Terms: International Roughness Index
• Subject Areas: Highways; Pavements; I23: Properties of Road Surfaces;

Filing Info

• Accession Number: 00715510
• Record Type: Publication
• Files: TRIS, TRB, ATRI
• Created Date: Dec 28 1996 12:00AM