Default Values for Capacity and Quality of Service Analyses

The Year 2000 Highway Capacity Manual (HCM 2000) is the most extensively referenced document on highway capacity and quality-of-service computations in the United States. While the HCM 2000 focuses on providing state-of-the-art methodologies for operational analyses, it is also used in planning and preliminary engineering applications. To assist engineers and planners in applying HCM methodologies, the HCM 2000 includes default values for many of the more difficult-to-obtain input parameters and variables. "A default value is a representative value that may be appropriate in the absence of local data" [HCM 2000]. As a result of insufficient field data, the HCM 2000 recommends only a single default value for many key data items, inadequately reflecting the variety of traffic and facility conditions across the United States. Because of limited resources or inexperience, analysts often use these default values inappropriately. The objectives of this project are to (1) determine appropriate default values for inputs to Highway Capacity Manual (HCM) analyses and (2) to develop a guide to select default values for various applications.


  • English


  • Status: Completed
  • Funding: $400000.00
  • Contract Numbers:

    Project 3-82

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway & Transportation Officials (AASHTO)

    444 North Capitol Street, NW, Suite 225
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Derr, B

  • Performing Organizations:

    Kittelson and Associates, Incorporated

    610 S.W. Alder Street
    Portland, OR  United States  97205
  • Principal Investigators:

    Zegeer, John

  • Start Date: 20050902
  • Expected Completion Date: 0
  • Actual Completion Date: 20070901
  • Source Data: RiP Project 10638

Subject/Index Terms

Filing Info

  • Accession Number: 01547925
  • Record Type: Research project
  • Source Agency: National Cooperative Highway Research Program
  • Contract Numbers: Project 3-82
  • Files: RIP
  • Created Date: Dec 17 2014 1:00AM