1. Transit Signal Priority: Managing Expectations Kevin N. Balke, Ph.D., P.E TransLink ® Research Center Director Texas Transportation Institute Transportation Research Board Meeting Washington D.C January 13, 2002

2. Presentation Outline  Transit Priority Theory  Historical Perspective  Future Perspective  On-going Applications  Implementation Issues  Managing Expectations

3. Historical Perspective Driver Judgment “Contact closure” Detection “Preempt” Signal Operations

4. Intelligent Traffic Signal Priority  Transit Vehicle Knows ….  Where it is  Whether it needs priority  Behind Schedule  Vehicle Occupancy  Its “budget” for priority  Traffic Signal Knows….  Where it is in its timings  Desired Time for Service of Vehicle  Relative “priority” of all requests

5. Priority Request Generators Priority Request Server Traffic Signal Controller Future TSP Perspective Estimated Time of Desired Service Priority Strategy

6. Implementations Issues MANAGING EXPECTATIONS!!

7. Managing Expectations: Bus Operations One Bus, One Route, One Trip Multiple Buses, Multiple Routes, Multiple Trips TRAFFIC MANAGER TRANSIT MANAGER

8. Managing Expectations: Scheduling With TSP, I can better achieve schedule! With TSP, I can set new aggressive schedule! If the schedule was good in the first place, why would I need TSP?

9. Managing Expectations: Responsiveness Time Savings To Transit Friendly Phase Priority Request Received Expectation Transit Friendly Phase Priority Request Serviced Time Savings To Transit Other Phases Reality

10. Managing Expectations: Time Savings 60 sec + 60 sec + 60 sec + 60 sec + 60 sec = 5 min Expectations 10 sec + 50 sec + 0 sec + 25 sec + 30 sec = 1 min 55 sec Reality

11. Managing Expectations: Coverage  Transit priority may NOT be appropriate everywhere!  Tightly-timed intersections  high volume, heavy congestion  Low volume intersections  greater flexibility  Balance between traffic and bus operations

12. Future of Signal Priority  NTCIP Traffic Signal Control Working Group  Tom Urbanik – Chair  Developing standards for signal priority control  Rail, Emergency Vehicles, Transit, Trucks  Transit first  Completed in Summer 2002

13. Questions