THE SYDNEY CO-ORDINATED ADAPTIVE TRAFFIC (SCAT) SYSTEM

The Department of Main Roads, New South Wales (DMR) is currently installing a utc system of 1,000 sets of traffic signals in the Sydney metropolitan area of 1000 sq km. The system comprises 11 regional mini-computers which are supervised by one centrally located mini-computer. All of the local controllers are micro-computers. The system architecture is one of distributed intelligence with a comprehensive and flexible communication system. An important feature is its integral cableless link mode of operation as a fall-back option. The plans and schedules for this operation are stored in the micro-computers from the regional computer and the local clocks are regularly checked. The normal mode of co-ordination is the dynamic method developed for the Sydney CBD system of 150 sets of signals. The method dynamically adjusts cycle, split and offsets in response to variations in traffic demand and capacity. Sufficient evidence exists to show that the method can produce significant improvements in delay reduction when compared to the optimised fixed-time methods preferred by most other authorities. A considerable number of improvements to the method have been made, particularly in the areas of detector data evaluation, cycle and split algorithms and in automatic calibration techniques. (TRRL)

• Record URL:
  http://arrbknowledge.com
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0869100971
• Supplemental Notes:
  • Proceedings from the Workshop on Area Traffic Control, Brisbane, August 1978.
• Corporate Authors:

  ARRB

  Melbourne, Victoria  Australia 
• Authors:
  • SIMS, A G
• Publication Date: 1979-5

Media Info

• Features: Figures;
• Pagination: p. 5-20
• Serial:
  • Publication of: Australian Road Research Board
  • Publisher: ARRB
  • ISSN: 0005-0164

Subject/Index Terms

• TRT Terms: Area traffic signal control; Business districts; Conferences; Microcomputers; Minicomputers; Reduction (Chemistry); Sensors; Traffic control; Traffic delays; Traffic signal control systems; Traffic signal controllers; Traffic signal cycle; Traffic signals; Urban areas
• Uncontrolled Terms: Decreases
• Geographic Terms: Australia
• Old TRIS Terms: Reduction; Traffic control systems
• ITRD Terms: 669: Area traffic control; 8006: Australia; 302: Business district; 8525: Conference; 576: Cycle (traffic signals); 9009: Decrease; 9010: Delay; 8673: Digital computer; 597: Linked signals; 6120: Sensor; 565: Traffic signal
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 00307995
• Record Type: Publication
• Source Agency: ARRB
• ISBN: 0 86910 097 1
• Files: ITRD, TRIS
• Created Date: Apr 22 1980 12:00AM