MTC Technology Transfer Seminar Transit Signal Priority

1. MTC Technology TransferSeminarTransit Signal Priority Abbas Mohaddes, President & CEO 714.780.7243 October 22, 2003

2. Seminar Objectives Brief description of BRT Defining TSP Signal Cycle Strategies Bus Location Methodologies Technical Considerations Case Study Examples Outline

3. Objectives • Briefly describe BRT • Define Transit Priority Methods • Identify Technology Solutions (State of the Art) • Discuss Operational Considerations • Present Lessons Learned

4. What is BRT? • BRT is an integrated bus-based “rapid” transit system • typically utilizing: • highly-flexible service and • advanced technologies to • improve customer convenience and reduce delays.

5. What Characterizes BRT • Ideal BRT will incorporate these components: • Enhanced stations • Advanced vehicles • Faster service • Modified route structure • Advanced fare collection • Intelligent transportation systems BRT is far more than a fancy new kind of vehicle

6. Upgrade of Busways to BRT Queue Bypass Signal Priority Special Access Potential Improvements Parking Management Dual Turn Lane Re-Entry Phasing Bus-Stop Improvements HOV Lane: HOV Emphasis Lane

7. Defining TSP

8. Transit Signal Priority ( TSP ) … provides for a traffic signal controller to react to the presence of an approaching bus and to give the bus its passage through the intersection with less delay than would have otherwise occurred.

9. Pre-Emption VS. Priority

10. Pre-Emption VS. Priority • Preemption(EVPE and RRPE): • Provides emergency vehicles with a green light at intersections during emergency situations • Also occurs at railroad and trolley crossings • Overrides the traffic signal system – – USUALLY NOTICEABLE !

11. Priority vs. Pre-Emption • Priority: • Occurs at locations where preferential treatment (i.e. a green light) is given to specific vehicles like transit buses • Moves transit riders through congestion faster • Increases transit vehicle’s average route speed • Often not noticeable - operates as part of the signal coordination

12. Rationale for Providing TSP • Improve Schedule Adherence • Reduce Bus Operating Costs • Speed up buses’ run times • Increase Transit Mode Split While concurrently … • Not significantly worsening overall delays

13. Signal Cycle Strategies

14. Signal Coordination Cycle

15. Green is Held

16. Green Extension

17. Early Green (red truncation)

18. Early Green (red truncation) Normal Start of Coordinated Green Start Green Early Coordinated Phase Shorten Other Splits

19. Transition/Recovery Varies from one controller software to another… • Early green needs no recovery • Controller is back in “sync” at the end of that coordinated green

20. Recovery from Early Green Recovery completed Recovery Cycle

21. Transition/Recovery Extended green TSP can recover in one of two ways: • Shorten the following non-bus phase, or • Give them their full split and shortening the next cycle’s bus phase

22. Recovery from Green Extension Start GreenHere? Or, here? Recovery Cycle

23. Queue-jumping A different form of TSP: • Detection is at / near the stopline • A normally-skipped, specially-inserted phase is called to serve the bus • Bus gets the green, while adjacent traffic is held a few seconds at a red

24. Queue Jump Geometry

25. ARTERIAL TRADITIONAL NEMA BARRIERS 12 10 4 1 2 3 4 7 OLB R1 SB QJ SB QJ 9 11 7 6 5 8 2 SIDE STREET R2 5 NB QJ NB QJ 1 6 Overlap A = phases 9+11 3 8 OLA Overlap B = phases 10+12 Queue Jump Phasing

26. Bus Location Methodologies

27. Locating the Transit Vehicle • Accurate Real-Time Position • To place a priority request not too early, not too late • Make an educated guess as to the transit vehicle’s precise ETA at the intersection • Only 2 Methods: • Intersection-to-Vehicle Proximity Detection • Continuous Vehicle Tracking

28. Optical - Strobe Lights Bus Location Technologies

29. Magnetic Detection-Inductive Loops Check-In Check-Out Bus Location Technologies

30. Bus Location Technologies RF / Infrared Tags RF /

31. Global Positioning Bus Location Technologies

32. Technical Considerations • Delays to Non-Transit Vehicles • Conditional Priority Methods • Bus Stop Location- Nearside VS. far side • Intersecting Bus Routes

33. Technical Considerations • Successive TSP Service Calls • Headway vs. Time Based Schedule Adherence • Benefit / Cost • Standards

34. Technical Considerations • Early and extended Green, or Extended Green only • Performance Measurement • Programming Difficulty

35. Case Studies • Glendale Centrally - directed • LADOT Centrally - directed • Sacramento County Watt Ave. • San Diego’s BRT – planning stage

36. City of Glendale (centrally-directed) • Buses tracked w/ GPS system • When a bus is determined to be late: • Bus location is compared to traffic signal • ETA is calculated for its predicted arrival

37. City of Glendale (centrally-directed) • Signal system sends TSP request to the target intersection • Controller activates internal TSP algorithm to produce: • Held Green, or • Early Green, or • Extended Green

38. Buses tracked bysignal system asthey pass over loop detectors Signal system predicts bus ETA at next upcoming traffic signal Signal system adjust splits (& phase sequence) to match green window to bus arrival LADOT (centrally-directed) LoopComm Detection

39. Changed Phase Sequence Normal Start of Coordinated Green Coordinated Phase Start Green WAY Early SWAP LT+Thru

40. Sacramento Watt Avenue TSP • Buses equipped with Opticom emitters • Opticom detectors’ range set for 10” of bus travel time • When zone is breached, TSP call is placed in Eagle (Siemens) controller • Internal controller algorithms allow for up to 10” of early or extended green

41. San Diego’s BRT (planned) • Wide variety of TSP technologies being examined • But controllers and system will be uniform across region (BI Tran) • Opticom exists, but older generation • Several Caltrans intersections in pilot corridor

42. Caltrans considerations • All Caltrans traffic systems use Caltrans software • CTNET – system for remote supervision • TRFM – field master controller software • C8 – local controller software (Type 170) • ACCMA Smart Corridors project has deployed TSP in Caltrans-controlled intersections for the first time

43. General Cost Implications • Just one factor in selecting an appropriate TSP solution • Costs vary depending on solution chosen • GPS-Based • Proximity zone-based • Loops

44. Strategies for Restricting TSP Conditional (aka Differential) TSP is applying TSP only to a subset of the bus fleet • Late buses only • Peak-direction buses only • Heavily-loaded buses only • No TSP for LOS E intersections during peak • No TSP within “x” minutes of a previous TSP event

45. Summary • BRT popularity is rapidly expanding! And TSP plays an important role in it. • TSP System must accurately predict bus arrival at intersection • To choose which TSP response to activate • Various TSP strategies exist…tailor to fit ! “Extended green” is best ! • Easiest to achieve • Biggest time-saving benefit • Can rebalance splits on following cycle