FLOW DEPENDENT TRAFFIC ASSIGNMENT ON A CIRCULAR CITY

CONSIDER A CIRCULAR CENTRAL BUSINESS DISTRICT OF A CITY WITH EVENLY SPACED RADIAL STREETS AND CIRCULAR STREETS. IT IS ASSUMED THAT DURING THE EVENING RUSH HOUR DRIVER ORIGINS ARE ALL INSIDE THE CITY AND EXITS AT THE CIRCUMFERENCE WITH A JOINT DISTRIBUTION THAT DEPENDS ONLY UPON THE RELATIVE ANGLE BETWEEN ORIGINAL AND FINAL RADII, AND THE RADIAL COORDINATE OF THE ORIGIN. TRAVEL TIME ON ANY DIRECTED LINK IS ASSUMED TO BE A FUNCTION OF THE FLOW ALONG THAT DIRECTED LINK AND THE RADIAL COORDINATE OF THE LINK. FOR A FLOW OF Q VEHICLES PER HOUR LEAVING THE CITY, THE PROBLEM IS TO FIND AN ASSIGNMENT OF DRIVERS TO PATHS SUCH THAT EVERY DRIVER FOLLOWS A PATH OF MINIMUM TRAVEL TIME BETWEEN HIS ORIGIN AND EXIT. IT IS FIRST SHOWN THAT THIS CIRCULARLY SYMMETRIC SYSTEM HAS GIVEN RISE TO A CIRCULARLY SYMMETRIC OPTIMAL FLOW PATTERN. THIS FLOW PATTERN CAN BE GENERATED BY ASSIGNING EACH DRIVER TO A PATH WHICH USES AT MOST ONE OF THE CIRCULAR STREETS. EVENTUALLY THE ASSIGNMENT IS EXPRESSED EXPLICITLY AS A FUNCTION OF UNKNOWN PARAMETERS WHICH SATISFY A SYSTEM OF EQUATIONS AND/OR INEQUALITIES. THE GENERAL SOLUTION OF THESE EQUATIONS WAS NOT FOUND, BUT SOLUTIONS WERE OBTAINED FOR A NUMBER OF SPECIAL CASES WHICH SHOWED THE EFFECT OF CONGESTION AT THE CENTER AND THE EFFECT OF A BELT EXPRESSWAY. DIFFERENTIAL EQUATIONS WERE ALSO OBTAINED. /AUTHOR/

  • Supplemental Notes:
    • Graduate RePT, 66 PP
  • Corporate Authors:

    University of California, Berkeley

    Institute of Transportation and Traffic Engineering
    Berkeley, CA  United States 
  • Authors:
    • Lam, T N
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00227679
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 15 2004 2:03AM