1. Transit Signal Priority: The Importance of AVL Data
David T. Crout Tri-County Metropolitan Transportation District of Oregon (TriMet)
Presented at
Transportation Research Board
83rd Annual Meeting
Workshop on Signal Control Priority for Transit Vehicles
January 11, 2004

2. Transit Signal Priority: The Importance of AVL Data
Project Partners
Transit Signal Priority: The Importance of AVL Data

3. Transit Signal Priority: The Importance of AVL Data
Tri-Met’s TSP Goals
Increase person trips through selected traffic corridors while minimizing impacts on minor movements.
Reduce transit running times.
Improve transit schedule reliability:
Reduce running time variability.
Reduce excess time built into schedule to offset variability.
Defer providing additional transit capacity.
Transit Signal Priority: The Importance of AVL Data

4. Transit Signal Priority: The Importance of AVL Data
Project Status
Five traffic corridors now activated within the City of Portland.
180 signals activated.
Now focusing on individual intersection “hot spots.”
Intersections analyzed for disproportionate delays to transit.
Anticipate approximately 120 additional intersections by early 2004.
Transit Signal Priority: The Importance of AVL Data

5. Two Types of Data Collected
TriMet AVL System
Two Types of Data Collected
Stops Data (Automatically Collected)
- Information collected at each bus stop
- Approximately 500,000 records per day
Event Data (Operator Generated Data)
- Special events at various locations
- Approximately 25,000 records per day
Transit Signal Priority: The Importance of AVL Data

6. Stops Data Event Data Bus Stop Location Pass up Overload
Actual Arrive Time
Actual Leave Time
Scheduled Time
Dwell
Door Opened
Ons & Offs (APCs)
Passenger Load
Lift Usage
Operator ID
Maximum Speed
Pass up Overload
Traffic Delay
Train/Bridge Delay
Fare Evasion
Graffiti/Vandalism

7. Transit Signal Priority: The Importance of AVL Data
TriMet TSP Overview
AVL System tracks bus location and schedule status.
If conditions are met, bus emitter (Opticom) communicates priority request to signal.
Signal controller then grants priority request.
Transit Signal Priority: The Importance of AVL Data

8. Emitter Activation Conditions
Transit Signal Priority: The Importance of AVL Data

9. Transit Signal Priority: The Importance of AVL Data

10. Evaluation Methodology
Comparison of transit performance from before TSP activation to after.
Relies on AVL:
Locational and temporal performance data is currently collected for all bus routes and at every bus stop.
Schedule adherence as well as travel time between stops can easily be determined.
Since distance between stops is known, gross speeds (i.e., including stops) can be calculated.
Transit Signal Priority: The Importance of AVL Data

11. Evaluation Methodology
Location & time bus starts and stops meeting TSP thresholds is also recorded.
TSP analysis segments defined as bus stop pairs in the vicinity of one or more signalized intersections.
Performance in areas affected by signal(s) can then be analyzed.
Separate segments are necessary for each direction.
Means of incorporating TSP analysis into GIS.
Transit Signal Priority: The Importance of AVL Data

12. Intersection Analysis
Route 4 – Division, SE 82nd Ave. & SE Division St.
Transit Signal Priority: The Importance of AVL Data

13. Intersection Analysis
Route 4 – Division, SE 82nd Ave. & SE Division St.
Transit Signal Priority: The Importance of AVL Data

14. Transit Signal Priority: The Importance of AVL Data
Trip-Level Analysis
*Prior to Implementation of TSP.
Transit Signal Priority: The Importance of AVL Data

15. Transit Signal Priority: The Importance of AVL Data
Preliminary Results
Travel time reduction of 2-3 minutes achieved after TSP implementation on Line 12, a high frequency trunk line.
Potential annual operating cost saving of $13,000.
June 2002 schedule re-written to remove one bus on Line 4 due to travel time and variability reductions.
Estimated annual operating cost savings of $60,000.
Estimated one-time capital cost savings of $300,000.
Transit Signal Priority: The Importance of AVL Data

16. Transit Signal Priority: The Importance of AVL Data
Any Questions?
David T. Crout
Transit Signal Priority: The Importance of AVL Data