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Transit Signal Priority Micro-Simulation: SR 51 Case Study

Transit Signal Priority (TSP) is a way to coordinate transit operations with traffic signals to improve travel times for transit riders. With TSP, a bus will automatically ask a signal to stay green long enough for the bus to get through the intersection and pick up/discharge passengers on the other side. This is a relatively inexpensive technology that is considered a key element in any on-street Bus Rapid Transit system.

In 2014, SPC studied TSP through a case study approach, simulating what would happen if it were to be implemented on the SR 51 Saw Mill Run corridor from SR 88 (the end of Port Authority’s South Busway) to the park-and-ride lot in Large. The computer simulation predicted savings to the transit operator that far exceeded the estimated costs of implementation, saving every bus trip through the corridor an average of 4.5 minutes (14%) during rush hour while having a negligible impact on auto traffic.

See below for:

  • One-page summary of TSP benefits
  • Technical report on the SR 51 Case Study
  • Appendix with technical information
  • Raw VISSIM simulation data files
  • A Power Point presentation summarizing the project
  • Computer simulation movies showing TSP in operation

The Report

SR 51 TSP Summary Sheet
One-Page SR 51 TSP Summary Sheet (PDF)
SR 51 TSP Summary Sheet
TSP SR 51 Final Report(PDF)
Also: Report Appendix | VISSIM Data Files (WinZip)

The Presentation

TSP Presentation (PPT, 156KB)

The Movies

Simulation #1: SR51 at Grace St

Transit Signal Priority allows the simulated bus to hold the green signal at Grace St. while it discharges and picks up passengers. The TSP system then automatically requests an extended green phase at Irwin.

Simulation #2: SR51 at Stewart

As southbound buses exit the South Busway, the timing guarantees that they will be stopped by a red light at Stewart Ave. With TSP active, the transit vehicle can get through the intersection at Stewart, and request a green extension again at Greenlea Rd.

Simulation #3: SR 51 at Brownsville Rd.

At one of the most congested intersections in the corridor, Transit Signal Priority could be combined with moving the bus stops to the far side of the intersection to get buses through much faster while having little impact on the side street traffic.

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