Simplified Highway Capacity Calculation Method for the Highway Performance Monitoring System

The Federal Highway Administration’s (FHWA's) Highway Performance Monitoring System (HPMS) provides information on the extent, condition, performance, use, and operating characteristics of the Nation’s highways. Each year State Transportation Agencies must submit HPMS data to the FHWA. The Sample Panel portion of HPMS provides detailed statistical data on a randomly selected sample of roadway sections on the State’s public road system. One data item submitted for sample panels is capacity (Sample Panel Data Item 69). The HPMS Field Manual guidance for capacity is as follows: “The capacity of a roadway facility is the maximum reasonable hourly rate at which vehicles can be expected to transverse a point or a uniform section of lane or roadway during a given time period under prevailing roadway, traffic, and control conditions.” Reasonable expectancy is that the stated capacity can be achieved repeatedly. The Highway Capacity Manual (HCM) provides procedures, formulas, graphics, and tables in assessing roadway capacity. This item should be estimated based on procedures consistent with the HCM. The results of the project are the development of: 1. Capacity computation methods that use HPMS data items to the extent possible, and can be used to validate HPMS Sample Panel Item 69; and 2. Simplified Methodologies to Create Generalized Level of Service (LOS) Lookup Tables. Both of these results use the most recent HCM methodologies. Specifically, it was found that the procedures in National Cooperative Research Program Report 825 (“Planning and Preliminary Engineering Applications Guide to the Highway Capacity Manual”) could be easily adapted to the types of data present in HPMS.

  • Record URL:
  • Corporate Authors:

    Cambridge Systematics, Incorporated

    4800 Hampden Lane
    Bethesda, MD  United States  20814

    Federal Highway Administration

    Office of Policy and Governmental Affairs, 1200 New Jersey Avenue, SE
    Washington, DC    20590
  • Authors:
    • Margiotta, Richard
    • Washburn, Scott
  • Publication Date: 2017-10-15


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Tables;
  • Pagination: 46p

Subject/Index Terms

Filing Info

  • Accession Number: 01677452
  • Record Type: Publication
  • Report/Paper Numbers: PL-18-003
  • Contract Numbers: DTFH61-13-D-00014
  • Files: TRIS, ATRI, USDOT
  • Created Date: Jul 30 2018 8:57AM