The National Academies

NCHRP 03-46 [Final]

Capacity and Level of Service at Unsignalized Intersections

  Project Data
Funds: $412,436
Research Agency: University of Idaho
Principal Investigator: Michael D. Kyte
Effective Date: 1/1/1993
Completion Date: 12/31/1995

The analysis procedures presented in Chapter 10, "Unsignalized Intersections," of the 1985 Highway Capacity Manual (HCM) were not based on delay and, therefore, were not compatible with the procedures in Chapter 9, "Signalized Intersections." The definition of level of service in terms of delay has gained wide acceptance, and Chapter 10 needed to include these measures. While the 1994 edition of the 1985 HCM did include delay estimation, the procedures were not extensively tested under U.S. conditions. There was also a need for additional guidance regarding the use of unsignalized versus signalized control at a given intersection, including correlation with warrant criteria contained in the Manual on Uniform Traffic Control Devices (MUTCD).

The objectives of this research were to (1) develop and validate capacity analysis procedures for stop controlled intersections to replace the existing procedures in the 1994 HCM Chapter 10, and (2) correlate these capacity procedures with the MUTCD warrants for installation of traffic signals and all-way stop control to provide consistency between the HCM and the MUTCD.

Status: The research is complete. The report will not be published but is available for viewing through the World Wide Web as shown below.

An article comparing the HCM methods of analyzing intersections and the MUTCD was published in the December 1997 issue of the ITE Journal.

Report Availability: The two volumes of the final report are available through the links below. The 1997 update to the HCM includes the analysis techniques developed in the project.

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