A NETWORK FLOW-ORIGIN DESTINATION ALGORITHM FOR ANALYSIS OF TRANSPORTATION SYSTEMS

THE PURPOSE OF THIS REPORT WAS TO PRESENT A NETWORK FLOW ALGORITHM FOR EVALUATING URBAN TRANSPORTATION SYSTEMS. THE TRAVEL DEMAND TO DRIVE THE ALGORITHM IS EITHER SURVEY ORIGIN/DESTINATION DATA OR ORIGIN/DESTINATION DATA GENERATED FROM A SPECIFICATION OF TRIP END LOCATIONS AND TRAVEL TIME DISTRIBUTION. THE STUDY CONTAINED DETAILED STATISTICAL ANALYSES AND DESCRIPTIONS OF THE ALGORITHM. IN NETWORK FLOW MODELING OF THE CITY, PERSONS TRAVELLING BETWEEN TWO LOCATIONS ARE VIEWED AS UNITS OF A COMMODITY THAT FLOW BETWEEN TWO NODES OF A FLOW GRAPH, ALONG LINKS OR ARCS. THE TRANSIT TIME ASSOCIATED WITH EACH ARC DEPENDS ON THE LEVEL OF USAGE. THE CITY IS REPRESENTED IN THESE TERMS BY SUBDIVIDING IT INTO A NUMBER OF GEOGRAPHICAL ZONES AND ASSOCIATING A NODE OF A FLOW GRAPH WITH EACH ZONE. THE TOTAL TRAVEL TIME OF A UNIT OF FLOW PASSING OVER MORE THAN ONE ARC FROM THE SOURCE OF THE DESTINATION IS THE SUM OF THE INDIVIDUAL LINK TRAVERSAL TIMES, ALONG ITS PATH. IF PASSAGE OR DELAY TIMES AT THE NODES ARE NONTRIVIAL, THE INTRODUCTION OF AN EXTRA ARC AT THE APPROPRIATE NODE REPRESENTS THESE INTERCHANGE TIMES. TRAVELERS CAN BE DISTRIBUTED THROUGH THE NETWORK ON ROUTES THAT PROVIDE THE SHORTEST TRAVEL TIMES FROM ORIGIN TO DESTINATION. TRIPS BETWEEN TWO ZONES CAN BE DISTRIBUTED IN SUCH A WAY THAT TRAVEL TIMES OVER ROUTES USED ARE EQUAL, WHILE TRAVEL TIME OVER ROUTES NOT USED ARE GREATER. /UMTA/

  • Supplemental Notes:
    • PROJ NO NSS-8
  • Corporate Authors:

    General Research Corporation

    Operations Analysis Division, Westgate Research Park
    McLean, VA  USA  22101
  • Publication Date: 1967-8

Subject/Index Terms

Filing Info

  • Accession Number: 00228244
  • Record Type: Publication
  • Source Agency: Urban Mass Transportation Administration
  • Files: TRIS, USDOT
  • Created Date: Jan 3 1973 12:00AM