1. 30th CAITR University of Western Australia December 12, 2008 Robert L. Bertini and Huan Li Conference for the Australian Institutes of Transport Research University of Western Australia December 11, 2008 Exploiting High Resolution Archived Transit Data for Improved Planning and Operations: A Portland, Oregon Case Study

2. 30th CAITR University of Western Australia December 12, 2008 Portland Founded 1851 530,000 in city 2 million people in metro area 145 mi 2 173 ft above sea level 78 miles to Pacific Ocean 65 miles to Palmer Glacier on Mt. Hood 36 in annual rainfall Largest wheat export port in U.S. 38 breweries inside metro area No sales tax No self-serve gas Distance between Perth and Portland: 9,231 miles (14,854 km)

3. 30th CAITR University of Western Australia December 12, 2008 Portland Founded 1851 530,000 in city 2 million people in metro area 145 mi 2 173 ft above sea level 78 miles to Pacific Ocean 65 miles to Palmer Glacier on Mt. Hood 36 in annual rainfall Largest wheat export port in U.S. 38 breweries inside metro area No sales tax No self-serve gas Distance between Perth and Portland: 9,231 miles (14,854 km)

4. 30th CAITR University of Western Australia December 12, 2008 Portland Founded 1851 530,000 in city 2 million people in metro area 145 mi 2 173 ft above sea level 78 miles to Pacific Ocean 65 miles to Palmer Glacier on Mt. Hood 36 in annual rainfall Largest wheat export port in U.S. 38 breweries inside metro area No sales tax No self-serve gas Distance between Perth and Portland: 9,231 miles (14,854 km)

5. 30th CAITR University of Western Australia December 12, 2008 About TriMet Serves 1.2 M population 575 mi 2 63.9 M annual bus trips 207,700 daily bus boardings 95 bus routes 655 buses 8100 bus stops Also LRT, Commuter Rail, Streetcar & Paratransit

6. 30th CAITR University of Western Australia December 12, 2008 TriMet’s Bus Dispatch System On- Board Computer Radio Doors Lift APC (Automatic Passenger Counter) Overhead Signs Odometer Signal Priority Emitters Stop Annunciation Memory Card Radio System Garage PC’s Radio Antenna GPS Antenna Navstar GPS Satellites Control Head

7. 30th CAITR University of Western Australia December 12, 2008 TriMet’s Bus Dispatch System Schedule deviation Control Head PCMIA Card Infrared APC Operator Input Dispatching Arrival Prediction

8. 30th CAITR University of Western Australia December 12, 2008 Stop Data TIME LINE DWELL TIME DOOR OPEN DOOR CLOSE ARRIVE TIME LEAVE TIME REWRITTEN ARRIVE TIME (IF DOOR OPENS) STOP LOCATION 15 METERS 30 METERS

9. 30th CAITR University of Western Australia December 12, 2008 TriMet’s Bus Dispatch System

10. 30th CAITR University of Western Australia December 12, 2008 Stop Data  Route Number  Vehicle Number  Service Date  Actual Leave Time  Scheduled Stop Time  Actual Arrive Time  Operator ID  Direction  Trip Number  Bus Stop Location  Dwell Time  Door Opened  Lift Usage  Ons & Offs (APCs)  Passenger Load  Maximum Speed on Previous Link  Distance  Longitude  Latitude

11. 30th CAITR University of Western Australia December 12, 2008 PORTAL Database Loop Detector Data 20 s count, lane occupancy, speed from 500 detectors (1.2 mi spacing) since 2004 Incident Data 140,000 since 1999 Weather Data Hourly since 2004 VMS Data 19 VMS since 1999 Bus Data 1 year stop level data 2007 140,000,000 rows Web Interface portal.its.pdx.edu

12. 30th CAITR University of Western Australia December 12, 2008 2007 AM Boardings

13. 30th CAITR University of Western Australia December 12, 2008 Passenger Movement

14. 30th CAITR University of Western Australia December 12, 2008 Fare Evasion

15. 30th CAITR University of Western Australia December 12, 2008 Background on Stop Location Challenges in delivering reliable and timely bus service Financial constraints Public transit operational issues Transit service generally favors bus stop accessibility Sometimes based on past history and tradition rather than rigorous ongoing analysis at the stop level

16. 30th CAITR University of Western Australia December 12, 2008 Stop Spacing Service Standards TriMet Portland  >80 units/acre: 400-600 ft  22-80 units/acre: 500-750 ft  4-22 units/acre: 600-1000 ft  <4 units/acre: as needed  Inner Portland has 200 ft blocks (264 ft street spacing)  Route 19 mean stop spacing is 942 ft (3 blocks)

17. 30th CAITR University of Western Australia December 12, 2008 Concept Derivation Trade off: person’s time in parallel access vs. another person’s time in riding. Minimize access cost: favors small s Minimize riding cost: favors large s

18. 30th CAITR University of Western Australia December 12, 2008 Assumptions Origins & destinations distributed along route in one dimension (ignore perpendicular access)… Average access distance (parallel only) = s /4 Assume number of passengers boarding or alighting at a stop to be ~Poisson distributed

19. 30th CAITR University of Western Australia December 12, 2008 Access Cost Value of Passenger Travel Distance p = density of trip origins plus density of trip destinations for passengers who board or alight the same vehicle (units: number/distance) s /4= average access distance (unit: distance)  = passenger access speed (unit: distance/time)  a = average cost per unit time per person for access (unit: cost/time) in interval of length s C a = [avg. no. of pax] [avg. dist traveled] [cost/unit dist]

20. 30th CAITR University of Western Australia December 12, 2008 Riding and Stopping Cost Value of in-vehicle passenger lost time due to boardings and alightings N = expected number of passengers on vehicle V = vehicle cruise speed  = time lost in stopping to serve passengers P r =1-e -p s = probability that vehicle actually stops (from Poisson for number of ons and offs)  r = average cost per unit time per person for riding in interval length s C r = [avg. no. of pax] [riding time + lost time] [cost/unit time]

21. 30th CAITR University of Western Australia December 12, 2008 [ ] / s Average Cost Per Unit Length Given that [access]  Average cost per unit length + [riding] + [stopping] Average cost per unit length = Independent of s ! Choice of s is independent of V, depends solely on     ps e )1( 

22. 30th CAITR University of Western Australia December 12, 2008 Objective Function Coverage for  >2 If β > 2:

23. 30th CAITR University of Western Australia December 12, 2008 p s = expected number of passengers to board or alight per stop

24. 30th CAITR University of Western Australia December 12, 2008 Case Study: Inbound Route 19 All Day 370 days (2/20/07 - 1/5/08) 19,344 trips 33.2 ons and offs/trip: Average passenger load/stop: 7.9 Route 19 Glisan to Portland Route Length: 9.27 mi Number of stops: 52 Mean delay due to stopping: 33.6 s Use 4ft/s walking speed

25. 30th CAITR University of Western Australia December 12, 2008 Route 19 Inbound Spacing Status

26. 30th CAITR University of Western Australia December 12, 2008 Optimized Spacing Calculation No. of passengers on vehicle N = 7.9 pax/stop Passenger ons and offs p s = 33.2 pax/trip Lost time  =33.6sec

27. 30th CAITR University of Western Australia December 12, 2008 2007 Time Space Passenger Load Plot Route 19 Time (hour) Distance (mi) 30 25 20 15 10 5 0 98765432109876543210 5 10 15 20

28. 30th CAITR University of Western Australia December 12, 2008 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 010203040 N (number of passengers on bus) Stop Spacing (ft) Route 19 Inbound Optimized Spacing Optimal February 20, 2007–January 5, 2008 For n = 790,392,  = 33.6 sec,  = 22.8 sec (range 1-100) Mean ons/offs = 33.2 Also shown are spacing plots for 20, 40 and 60 ons/offs Step function based on 20 blocks/mile 20 ons/offs 60 ons/offs 40 ons/offs 20 blocks/mile 33.2 ons/offs

29. 30th CAITR University of Western Australia December 12, 2008 Sensitivity Analysis 1/21/31/4 Optimized Spacing (ft)172814111222 Access Cost Value of access time ($/hr)$ 16/hr$ 18/hr$ 20/hr Before optimized (passenger $/unit length)$ 0.64$ 0.72$ 0.80 After optimized (passenger $/unit length)$ 1.18$ 1.08$ 1.04 Change (passenger $/unit length)+0.54+0.36+0.24 Riding Cost Value of riding time ($/hr)$ 8/hr$ 6/hr$ 5/hr Before optimized (passenger $/unit length)$ 2.30$ 1.72$ 1.44 After optimized (passenger $/unit length)$ 1.83$ 1.50$ 1.32 Change (passenger $/unit length)-0.47-0.22-0.12

30. 30th CAITR University of Western Australia December 12, 2008 Conclusions 12 stops are recommended for consolidation The trip time would be reduced by 3.4 min/trip The total savings due to consolidation could be up to 3.7 hours of service time per day Allow the addition of approximately 7.6 additional trips per weekday Mean weekday headway would drop from 18.0 min to 16.1 min Total of 17,076 inbound trips, the time saved would be 977 hours during the year Assuming $60/hr operating cost, about $60,000 could be saved by TriMet

31. 30th CAITR University of Western Australia December 12, 2008 Next Steps Route 19 AM Peak Inbound (TRB 2009), PM Peak Outbound Automate process for all routes Produce quarterly reports for TriMet Verify “real” cost savings Consider “real” relationship to demand and equity Connect to scheduing

32. 30th CAITR University of Western Australia December 12, 2008 Acknowledgements Huan Li, Ph.D. Student David Crout of TriMet for providing the rich data set that facilitated this analysis Gordon Newell Prof. Michael Cassidy, University of California at Berkeley, for his assistance in developing the analytical framework for this paper bertini@pdx.edu www.its.pdx.edu