WHEN MIXED CYCLE LENGTH SIGNAL TIMING REDUCES DELAY

In a few systems, cycle lengths at some intersections are 2-thirds the length of that used at the remaining intersections; the shorter lengths are used where approach volumes are lower. This article shows how mixed cycle lengths can result in better system performance and how to determine whether improvement will result in any particular situation. TRANSYT, which employs a model of traffic flow which takes into account the dispersion of platoons, was used to evaluate mixed cycle length timing patterns. It was found that it is necessary to select the cycle lengths at the various intersections that deep the number of transitions between cycle lengths to a minimum if a mixed cycle length timing pattern is to give better results than a common cycle length for all intersections. The optimum cycle length for an isolated intersection is discussed, and an example (an arterial network generated with 10 intersections one of which had a much longer Webster cycle length due to heavy cross street traffic) is described to demonstrate the capabilities of mixed cycle timing patterns. Another situation where mixed cycle length timing patterns can be superior is where the network includes a complex intersection requiring more phases per cycle.

• Corporate Authors:

  Institute of Traffic Engineers

  2029 K Street, NW
  Washington, DC    20006
• Authors:
  • Kreer, J B
• Publication Date: 1977-3

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 17-20
• Serial:
  • Traffic Engineering
  • Volume: 47
  • Issue Number: 3
  • Publisher: Institute of Traffic Engineers

Subject/Index Terms

• TRT Terms: Approach lanes; Intersections; Traffic delays; Traffic platooning; Traffic signal cycle; Traffic volume
• Uncontrolled Terms: Timing
• Old TRIS Terms: Intersection approach
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00157271
• Record Type: Publication
• Files: TRIS
• Created Date: Nov 23 1977 12:00AM