COMPARISON OF FIXED TIME AND FLEXIBLE PROGRESSIVE TRAFFIC CONTROL IN SLOUGH

Since 1977 Slough Borouch Council have operated a compact urban traffic control (utc) system in which a central computer coordinates the timings of traffic signals in slough. The signals are controlled by a flexible progressive system in which the central computer allows the timings to vary by a few seconds from the present" fixed time plans" which maintain coordination. The variations in timings are determined by the presence or absence of vehicles over stop-line detector loops; similar systems have been used for many years at other sites. In spring 1983, the TRRL conducted a survey to compare the flexible progressive system with a fixed time system that used the same coordination plans. A "floating car" survey method was used to measure journey times along the A4 Bath road and A355 Farnham road during four periods of the day for five weeks in spring 1983. The results show no significant differences in journey times measured with the two control systems, although there is some indication that the flexible progressive system gives slightly shorter journey times in the morning peak. It is possible that the flexible progressive control system can adapt to small changes in flow, and so reduce the need for updating the fixed time plans. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03051315
• Corporate Authors:

  Transport and Road Research Laboratory (TRRL)

  Wokingham, Berkshire  United Kingdom 
• Authors:
  • LINES, C J
  • Lucas, C F
• Publication Date: 1984

Media Info

• Features: Figures; References; Tables;
• Pagination: 8 p.
• Serial:
  • Supplementary Report
  • Publisher: Transport and Road Research Laboratory (TRRL)
  • ISSN: 0305-1315

Subject/Index Terms

• TRT Terms: Alternatives analysis; Area traffic signal control; Computers; Detectors; Electromagnetic induction; Optimization; Pretimed traffic signal controllers; Traffic control; Traffic delays; Traffic flow; Traffic signal control systems; Traffic signal cycle; Traffic signal timing; Traffic signals; Traffic surveys; Travel time; Trip length; Urban areas
• Uncontrolled Terms: Optimum
• Geographic Terms: United Kingdom
• Old TRIS Terms: Flexible progressive system
• ITRD Terms: 669: Area traffic control; 576: Cycle (traffic signals); 9010: Delay; 8673: Digital computer; 6927: Induction; 697: Journey time; 597: Linked signals; 6120: Sensor; 671: Traffic flow; 565: Traffic signal; 676: Traffic survey; 8119: United Kingdom; 313: Urban area
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00396004
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Report/Paper Numbers: SR 837
• Files: ITRD, TRIS, ATRI
• Created Date: Jan 31 1986 12:00AM