The document discusses Transit Signal Priority (TSP), a strategy designed to enhance transit vehicle movements at intersections while considering the impacts on other users like cars, pedestrians, and cyclists. It highlights various operational strategies, testing procedures, and the importance of analyzing transit needs against cost-benefit ratios. TSP can improve schedule reliability for transit but may introduce complexities and safety concerns for other intersection users.

1. Impact on intersection efficiency and safety
for all users
Transit Signal
Priority

2. Authors
 Stephan Kellner, Eng., P.Eng., MS
 François Bélisle, Eng. jr., B.Sc., M.Sc.
2

3. Presentation outline
3
 Introduction
 Basic operation principles
 Operation strategies
 System test
 Considerations
 Impact on all users
 Conclusion

4. Introduction
4
 Transit Signalisation Priority
(TSP)
− Operational strategy to
facilitate transit vehicle
movements (1)
− Enhances transit
movements without
undue impact on other
users

5. Basic operation principles
5
 Vehicle detected upstream
 Requests
− All or some requests are
accepted
− Request transmitted to
traffic controller
 Detected vehicle passes
through intersection
 Confirmation transmitted to
controller
 Return to normal operation

6. Basic operation principles
6
 On-board interface
 Emitter
 Check-in detection zone
 Check-out detection zone
 Traffic controller
(w/ or w/o interface)
 Optional: connection to
centralized traffic control
centre (CTC)

7. Operation strategies
7
 Passive systems (w/o detection)
− Optimization to enhance
transit operation
• Cycles
• Timings
• Offsets
 May be sufficient for certain
agencies and certain
intersections

8. Operation strategies
8
 Active systems (w/ detection)
− Green extension
− Red truncation
− Phase rotation
− Addition of transit phases
 May be too costly for certain
problems and agencies
 May have too much impact on
other users

9. Operation strategies
9
 Simple strategies
− All requests from vehicles
executed
• Detection upstream,
according to speed
• Assumes constant speed
• Works w/ green extension
 Complex strategies
 Transit priority for vehicles
behind schedule only
- Intelligent interface, or
- CTC
 Eliminating queues in front
of transit vehicles
- Queue detection needed
- Exact location of transit
vehicle

10. System test
10
 System test
− TSP can be a complex
system
− Apply software integration
procedures
 Establish procedures to
− Test
− Verify
− Validate
 Testing of all components
 On test-bench
 Before installation
 After installation
 Validation of detection zones
with equipment in place
 Validation of communication
with CTC

11. Considerations
11
 Physical
− Bus stop location (far-
side, near-side)
− Detection (equipment,
zones)
− Screening of requests
(vehicle ready, stopped,
behind schedule, etc.)

12. Considerations
12
 Traffic signals
− Equipment compatibility
− Communication
equipment
− Link with CTC

13. Considerations
13
 Strategic
− Delays due to signals?
− Regularity impacted by
signals?
− Use of passive TSP?
− Use of active TSP?
− Other agencies?
− Cost/benefit ratio
positive?
 Expected results (2,3,4,5)
 Signal priority mostly affects
travel time variability
 May not reduce wholesale
travel time
 Often unrealistic to expect to
reduce number of buses

14. Impact on all users
14
 TSP is best for schedule
reliability
 Often side benefit of travel-
time savings
 One priority request can
impact another
 Vehicles running ahead of
schedule are not positive
 Impact on other users
 Cars
 Pedestrians
 Cyclists
 Other transit users
 The extra time for transit comes
from somewhere…

15. Impact on all users
15
 Safety considerations
− Undue delays create
unsafe behavior(6)
− Inconsistent signal timing
= unexpected signal
timing
− Elevated signal cycles
− More or less congestion
at intersections

16. Impact on all users
16
 Pedestrians and cyclists
− Bus stop location vs
• Walking distances
• Bike path routing
− Queue jumps vs cyclists
− Pedestrian crossing times

17. Conclusion
17
 TSP can have positive
impact on transit operations
(regularity)
 TSP has impacts on other
users
 TSP can be costly
 Analysis of transit needs and
agency procedures is
important
 Considering all users in cost-
benefit analysis

18. References
1. Transit Signal Priority: A Planning and Implementation Handbook. ITS
America. 2005.
2. Transit Signal Priority: Advanced Control Logic to Really Benefit Transit.
Peter G. Furth, Northeastern University. Boston, MA. 2009.
3. TCRP 110: Commonsense Approaches for Improving Transit Bus
Speeds. TRB 2014.
4. Simulation of Transit Signal Priority Using the NTCIP Architecture.
Hongchao Liu, Texas Tech University; Alexander Skabardonis, University
of California, Berkeley; Meng Li, University of California, Berkeley.
Journal of Public Transportation, 2006 BRT Special Edition.
5. Transit Signal Priority Systems Application and Technology Investigation.
Christopher G. Hedden. NJDOT. 2009.
6. Traffic Safety on Bus Priority Systems, World Resources Institute report,
2014.

19. Questions?
19
 Stephan.Kellner@wspgroup.com
 Francois.Belisle@wspgroup.com