New Chapter 26 for the Highway Capacity Manual: "Interchange Ramp Terminals"

Diamond interchanges, partial cloverleaf interchanges and single point urban interchanges have been basic freeway design since freeways were first constructed. However, until recently, no accepted methodology was available to help reviewing agencies know whether or not the interchange operations analyses presented to them were reliable. In a newly approved chapter of the Highway Capacity Manual, a procedure has been developed to analyze these interchanges. The new chapter incorporates characteristics that are unique to interchanges and includes: redefining levels of service A to F to better reflect the types of delays encountered at interchanges; origin-destination characteristics of turning movements at interchanges; operational effects of intersection spacing; lane utilization for both through and turning movements at an interchange; demand starvation; and interchange type selection analysis to help determine the impacts of changing interchange types. Two types of analyses for signalized interchanges are supported in the new chapter: final design and operational analysis.

  • Availability:
  • Authors:
    • Marcuson, Joel K
    • Elefteriadou, Lily
    • Dowling, Richard
  • Publication Date: 2007-6


  • English

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Filing Info

  • Accession Number: 01053692
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 9 2007 10:57PM