TESTS ON A HEURISTIC ALGORITHM FOR A COMBINED ATC- ASSIGNMENT PROBLEM

This paper was presented at Session 33 - Area Traffic Control. This paper investigates the feasibility of achieving optimal solutions for a combined area traffic control (atc) and assignment problem under different testing conditions. A sequential combination of a signal optimisation program, TRANSYT, and a traffic assignment program, ARRBTRAFIC, is adopted. Signal settings obtained from TRANSYT are used to derive non-decreasing delay functions suitable for obtaining either user-optimal or system-optimal flow patterns from ARRBTRAFIC. The new flow pattern obtained after assignment is fed bact to TRANSYT to form an iterative procedure. Based on a test network, the results indicate that there is only a small difference between user-optimal and system-optimal traffic assignments, and that equilibrium solutions depend on initial conditions. These solutions are therefore not global optimal solutions. The existence of local minima can be attributed to a positive feedback mechanism inherent in atc. A combined atc-assignment problem becomes a non-convex problem if this positive feedback dominates the re-routing effect of traffic assignment. (TRRL)

• Record URL:
  http://arrbknowledge.com
• Supplemental Notes:
  • Proceedings from the Ninth Australian Road Research Board Conference, Brisbane, 21-25 August 1978.
• Corporate Authors:

  ARRB

  Melbourne, Victoria  Australia 
• Authors:
  • Luk, J Y
• Conference:
  • Australian Road Research Board Conference Proc
• Publication Date: 1979

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 213-220
• Serial:
  • Volume: 9
  • Issue Number: 5

Subject/Index Terms

• TRT Terms: Algorithms; Area traffic signal control; Computer programs; Conferences; Equations; Equilibrium (Mechanics); Mathematical models; Networks; Optimization; Planning; Traffic assignment; Traffic control; Traffic flow; Traffic signal controllers
• Uncontrolled Terms: Transportation networks
• Old TRIS Terms: Traffic control systems
• ITRD Terms: 669: Area traffic control; 8525: Conference; 6473: Mathematical model; 1054: Network (traffic); 143: Planning; 8645: Software; 679: Traffic assignment
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; I73: Traffic Control;

Filing Info

• Accession Number: 00309188
• Record Type: Publication
• Source Agency: ARRB
• Files: ITRD, TRIS, ATRI
• Created Date: May 21 1980 12:00AM