OPTIMIZATION OF TIME-OF-DAY BREAKPOINTS FOR BETTER TRAFFIC SIGNAL CONTROL

Traffic signal control is one of the most cost-effective means of improving urban mobility. Signal control can be categorized as pretimed, actuated, and adaptive. Among these, both pretimed and coordinated actuated controllers deploy multiple signal timing plans to account for traffic demand changes during the day, whereas adaptive control changes the timing plan in real time according to traffic conditions. In the case of pretimed and coordinated actuated signals, morning peak traffic would differ from that of the off-peak such that it would be better to use two distinctive signal timing plans. Traffic engineers often determine such time-of-day (TOD) breakpoints manually by using 1 or 2 days worth of traffic data. A few recent studies developed statistical and heuristic methods for TOD breakpoints by using archived traffic data. These approaches determined the breakpoints through minimization of within-cluster distance and maximization of between-cluster distances. Thus, the clusters do not directly reflect the performance of timing plans and often result in only local optimal TOD breakpoints. One method is based on a genetic algorithm (GA) that optimizes TOD breakpoints with explicit consideration of signal timing performance at a representative intersection. The proposed method implements two-stage optimizations: outer loop for TOD breakpoints and inner loop for timing plans of corresponding intervals. The proposed approach is implemented on a network consisting of three coordinated actuated signalized intersections. The convergence graphs of both inner- and outer-loop optimization indicate that the GA-based algorithm obtains breakpoints within a relatively small number of iterations. Also studied was the performance of the proposed approach for a varying number of breakpoints (i.e., four to eight). The results, based on a microscopic simulation program, SimTraffic, indicated that six breakpoints outperformed the other numbers of breakpoints considered.

• Record URL:
  https://doi.org/10.3141/1867-25
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=OPTIMIZATION+OF+TIME-OF-DAY+BREAKPOINTS+FOR+BETTER+TRAFFIC+SIGNAL+CONTROL&author=B.+PARK&author=P.+Santra&author=I.+Yun&author=D.+Lee&publication_year=2004
• Availability:
  • Find a library where document is available. Order URL: http://www.trb.org/Main/Public/Blurbs/155184.aspx
• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1867, Freeway Operations and Traffic Signal Systems 2004.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Park, B
  • Santra, P
  • Yun, I
  • Lee, D-h
• Publication Date: 2004

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 217-223
• Monograph Title: FREEWAY OPERATIONS AND TRAFFIC SIGNAL SYSTEMS 2004
• Serial:
  • Transportation Research Record
  • Issue Number: 1867
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Actuated traffic signal controllers; Adaptive control; Genetic algorithms; Microsimulation; Optimization; Periods of the day; Pretimed traffic signal controllers; Traffic signal control systems; Traffic signal timing
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 00978548
• Record Type: Publication
• ISBN: 0309094615
• Files: TRIS, TRB, ATRI
• Created Date: Sep 23 2004 12:00AM