The author traces the development of traffic lights and suggests that with the current computer techniques available urban traffic could be managed with greater finesse. A detailed account is given of the prodyn system and explanatory diagrams provided. Vehicles or pedestrians are detected by sensors and using a prediction model prodyn simulates how the process will evolve and generates the appropriate command. The command is the decision whether to change any of the lights from one phase to another. A novel feature of the method is its non-cyclic character due to the possibility of changing lights being examined every 5 seconds. Details of the optimisation process and the methods by which arrivals at the crossroads may be measured are given. On-going research is described which is taking account of real-life situations and comparing the system with conventional fixed-time methods. The problem of measurement point failures is considered and prodyn found to perform better under these conditions than conventional systems due to its data restoration facility. Work is being carried out to reduce high capital costs due to the large number of measurement points. This article was originally published in French in: bulletin zelt, (June 1985), no 3, p4-14.

  • Corporate Authors:

    Transport and Road Research Laboratory (TRRL)

    Wokingham, Berkshire  United Kingdom 
  • Publication Date: 1988-8


  • English

Media Info

  • Pagination: 11 p.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00498766
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: T 3453
  • Files: ITRD, TRIS
  • Created Date: Sep 30 1990 12:00AM