Signal Timing Optimization Methodologies and Challenges for the City of Baltimore Central Business District and Gateways

Signal timing optimization challenges and methodologies for a 425-signal optimization project in the City of Baltimore, Maryland are discussed in this paper. This project included 250 signals in a grid Central Business District (CBD) and 175 signals on gateways leading to and from the CBD. This project is by far one of the largest single task signal optimization projects in the country and the project encompasses many unique scenarios and solutions. The project presents many challenges with signal timing optimization philosophies and strategies, at-grade light-rail crossings, pedestrian clearances, advance and exclusive pedestrian phases, transit signal priority, cycle length selection, network partitioning, coordination analysis, cross street coordination, queue management, calibration of the optimization model and selection of performance measures and a 12-months completion schedule. This paper discusses the details of these challenges, identifies the solutions implemented and reports on lessons learned from the project. This paper documents various state-of-the-practice data collection methodologies for turning movement counts, travel time, queues, stops and intersection delays. State-of-the-art global positioning systems (GPS) equipment are used to collect all field data for the “before and after” signal timing optimization” periods, with the exception of turning movement counts. The model calibration methodology was an extensive task that proved to be very valuable in making the model reliable and credible. The methodology for the calibration and validation for this large network was very unique and it required the collection of saturation flow rates, queues and speeds in several zones in the City. The benefits in reduced delays, stops and emissions under this optimization effort were overwhelming and the project paid for itself in less than 3 months.

• Corporate Authors:

  Institute of Transportation Engineers (ITE)

  Washington, DC  United States 
• Authors:
  • Riniker, Keith
  • Silberman, Paul
  • Sabra, Ziad A
• Conference:
  • ITE 2007 Annual Meeting and Exhibit
  • Location: Pittsburgh PA, United States
  • Date: 2007-8-5 to 2007-8-8
• Publication Date: 2007

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Maps; Photos; Tables;
• Pagination: 18p
• Monograph Title: 2007 Annual Meeting and Exhibit Compendium of Technical Papers

Subject/Index Terms

• TRT Terms: Central business districts; Optimization; Queuing; Traffic signal cycle; Traffic signal priority; Traffic signal timing
• Geographic Terms: Baltimore (Maryland)
• Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 01362717
• Record Type: Publication
• Files: TRIS
• Created Date: Feb 16 2012 10:14AM