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Abstract The City of Portland, in collaboration with TriMet (Portland’s regional transit service provider) and the Oregon Department of Transportation, has implemented transit signal priority (TSP) at more than 240 intersections on seven transit routes as a part of the Streamline program. This study focuses on the simulation of one intersection in Portland by using hardware- in-the-loop simulation to examine the effects of TSP signal control strategies on transit performance. More specifically, near- and farside bus stops are studied with hardware-in- the-loop traffic simulation to determine the effect of stop location on the effectiveness of the Portland TSP system. This analysis is verified by using a deterministic spreadsheet model to determine the effectiveness of the system and to address whether a green time extension plan should be used if there is passenger activity at a nearside stop. Objectives Conclusions Acknowledgements The authors acknowledge the support of the City of Portland, TriMet, ODOT, and the Portland State University Department of Civil and Environmental Engineering for their support. In addition, they particularly thank Bill Kloos, Willie Rotich, and Paul Zebell, of the City of Portland; Kiel Ova, of PTV America; and Karen Giese and Selman Altun, of Kittelson & Associates, Inc. The authors acknowledge the valuable assistance provided by Matt Lasky in the completion of this paper. Using Hardware-in-the-Loop Simulation to Evaluate Signal Control Strategies for Transit Signal Priority Neil Byrne, Robert L. Bertini, Chris Pangilinan and Matt Lasky, Portland State University; Peter Koonce, Kittelson & Associates, Inc. On- Board Compute r Radio Doors Lift APC (Automatic Passenger Counter) Overhead Signs Odometer Signal Priority Emitters Memory Card Radio System Garag e PC’s Radio Antenna GPS Antenna Navstar GPS Satellites Control Head Conditional Priority with TriMet’s Bus Dispatch Syst Study Design • Model a single intersection • N. Killingsworth at N. Albina • VISSIM 3.70 • Model 170E Signal Controller • NIATT Controller Interface Device • “Hardware-in-the-loop” simulation • With no Transit Signal Priority, bus stop location has a negligible effect on delays and travel times. • With Transit Signal Priority AND a very high stop utilization, far side stops are clearly beneficial. • Minimal increase in side street delay with short cycle length (70 seconds) and modest volume to capacity ratios. • Future • Effect of detection length • Different Transit Signal Priority plans (i.e. no green extensions) • Traffic volumes N 500’ Study Design • TSP Detection Range = 500’ • 12 minute one-way headways • Dwell times of 20-40 seconds • 70 second cycle time • 31 green, 3 amber, 1 AR • Green Extension: + 12 seconds • Red Truncation: - 12 seconds • 25-hour real-time simulation runs for each scenario, 2 runs per scenario TSP No TSP Near Side Stop X X Far Side Stop X X Far Side Transit Stops Near Side Transit Stops Travel Times Far Side: -11% Near Side: +6% Intersection Delay Far Side: -33% Near Side: +18% Side Street Delays Minimal delays D elay Per B us 0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 0% 25% 50% 75% 100% Stoppage Percent D elay (seconds) NearSide NearSide TSP FarSide FarSide TSP TravelTim e PerBus 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 0% 25% 50% 75% 100% Stoppage Percent Tim e (seconds) N earS ide N earS ide TS P FarS ide FarS ide TS P • Stop Utilizatoin: 0%, 25%, 50%, 75%, 100% • Near Side/Far Side similar with 0% stoppage • Near Side reacts as if it was a Far Side stop • Near Side delay reductions decrease with higher utilization • Far side receives benefits regardless of stoppage • Near Side travel time reduction occurs in every scenario EXCEPT 100% stoppage • Far side receives travel time reduction for all scenarios. • Far Side results have better consistency with TSP • Unpredictability of dwell time for Near Side can make call for TSP ineffective. Conditional Priority Framework Green Extension Red Truncation Yes Yes Yes Is bus within the City of Portland? Is the bus on its proper route? No Are the bus doors closed? Is the bus behind schedule? Request Priority Priority Disabled Is the bus on schedule? Has the request already been sent? Yes No Yes No No Yes No No • Examine relationship between Transit Signal Priority and bus stop location • Explore concept of hardware-in-the-loop simulation • Measures of Effectiveness • Bus Travel Times • Bus Intersection Delays • Side Street Delays www.its.pdx.edu
