The feasibility is considered of linked traffic signal systems in order to control the capacity of streets at various levels of traffic flow. The limitations are discussed of the existing systems (based on the criterion that journey times or similar functions should be minimized) and alternatives are suggested. These include the limiting of traffic volumes in order to optimize the travel benefits as a proxy for road pricing; limiting traffic volumes within an area according to it's environmental capacity; maximizing the capacity of a road forming a closed loop around the area of restraint. The implementation is discussed of such systems, and a possible basis is indicated for maximizing the capacity of a road forming a closed loop and the reasoning behind such a policy. The simplest method assumes that the various traffic flows are fixed in proportion to one another; it is then possible to find which junction is critical, and all other junctions will have a reserve capacity. However, if the flows entering the loop road at the junctions are considered as variable, then a linear programming technique can be used in order to maximize the total entry volume. It is assumed that the capacity is limited by the junctions rather than the roads between the junctions. It is then necessary to check for feasible linkages between signals, in order to confirm that this is the case. Vehicle actuated controls are discussed which are necessary to regulate such high capacity systems.

  • Supplemental Notes:
    • PTRC Summer Annual Meeting, 8-12 July, 1974, University of Warwick.
  • Corporate Authors:

    Planning and Transport Res and Computation Co, Ltd

    40 Grosvenor Gardens
    London SW1,   England 
  • Authors:
    • Bacon, W
  • Publication Date: 1974-7

Media Info

  • Features: Figures; References;
  • Pagination: 15 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00264030
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 31 1974 12:00AM