Development of a Transit Model Incorporating the Effects of Accessibility and Connectivity

1. Development of a Transit Model Incorporating the Effects of Accessibility and Connectivity 9th Conference on the Application of Transportation Planning Methods Baton Rouge, Louisiana April 6-10, 2003

2. Research Team • Ram M. Pendyala Dept of Civil & Environmental Engineering, Univ of South Florida, Tampa • Steve Polzin & Xuehao Chu Center for Urban Trans Research (CUTR), Univ of South Florida, Tampa • Seongsoon Yun Gannett Fleming, Inc., Tampa • Fadi Nassar Keith & Schnars PA, Fort Lauderdale • Project Manager: Ike Ubaka Public Transit Office, Florida Dept of Transportation, Tallahassee • Programming Services: Gannett Fleming, Inc.

3. Outline • Background • History of transit model development in Florida • BEST 3.0: Third generation transit model system • Role of accessibility and connectivity • BEST 3.0 methodology • Accessibility/connectivity methodology • Model development • Data • Estimation • Application

4. Background • Transit systems planning and analysis • Accessibility • Availability • Quality of Service • Ridership • Temporal Characteristics • Transfers • Route/Network Design • Fare Policies and Structure • Alternative Modal Options/Technologies/Route Types • Disaggregate Stop-Level Analysis

5. History of Transit Model Development • FDOT Public Transit Office very proactive in transit planning tool development • TLOS, FTIS, and INTDAS examples of transit planning and information tools • Transit ridership modeling tools • ITSUP: Integrated Transit Demand & Supply Model • RTFAST: Regional Transit Feasibility Analysis & Simulation Tool • Powerful stop-level ridership forecasting models

6. Stop-Level Ridership Forecasting • First generation ITSUP sensitive to demographic variables and frequency and fare of service • Second generation RTFAST accounted also for network connectivity (destination possibilities) • Desire transit ridership forecasting model that accurately accounts for accessibility/connectivity • Third generation model called BEST 3.0 • Boardings Estimation and Simulation Tool

7. BEST 3.0 • Model estimates number of boardings at stop by: • Route • Direction • Time period • Model estimates two types of boardings: • Direct Boardings: Walk and Bike Access • Transfer Boardings: Transit Access

8. Separating Direct and Transfer Boardings • Consider two types of stops, i.e., stops with no transfer possibility and transfer stops • Estimate direct boardings model using data from non-transfer stops • Apply direct boardings model to transfer stops to estimate direct boardings at transfer stops • Subtract estimated direct boardings from total boardings to estimate transfer boardings • Then estimate transfer boardings model

9. Role of Accessibility and Connectivity • Transit ridership strongly affected b y: • Destination accessibility • Temporal availability • Network connectivity • Desire to have BEST 3.0 sensitive to all three aspects of transit accessibility • Ability to test effects of alternative route and network design configurations on transit boardings • Sophisticated methodology incorporated into BEST 3.0

10. BEST 3.0 Methodology • s refers to stop on a route in a given direction and n refers to time period • D = direct boardings • R = number of bus runs • B = vector of buffer characteristics • Oi = vector of accessibility to characteristics of buffer areas for Hi stops, i = 2, 3, 4, 5 • X = vector of other route and stop characteristics

11. BEST 3.0 Methodology • T = transfer boardings • O1 = vector of accessibility of boarding at H1 stops during period n toward stop s • Y = vector of other route and stop characteristics • Methodology thus includes both direct and transfer boardings equations • Accessibility vectors play major role

12. 14 14 14 14 Definition of Stops • Stops are defined with three pieces of information: • Physical location • Route • Direction • Example 1: • 2 routes intersect • Example 2: • 4 routes serve one location in the same direction

13. Neighboring Stops • N1 = Neighboring stops along the same route • N2 = Stops along the same route but in the opposite direction that lead to different destinations providing the same opportunities. • N3 = Neighboring stops along other routes that lead to different destinations providing access to opportunities for the same activities. • N4 = Neighboring stops along other routes that lead to the same destinations. These routes may or may not share the same roads with the particular route in question

14. Neighboring Stops (N1) • N1 = Neighboring stops along the same route Stop in Question

15. Neighboring Stops (N2) • N2 = Stops along the same route but in the opposite direction that lead to different destinations providing the same opportunities Stop in Question

16. Neighboring Stops (N3) • N3 = Neighboring stops along other routes that lead to different destinations providing access to opportunities for the same activities 14 14 14 14 14 Stop in Question

17. Neighboring Stops (N4) • N4 = Neighboring stops along other routes that lead to the same destinations; these routes may or may not share the same roads with the particular route in question Stop in Question

18. Competing Routes/Stops • Notion of neighboring stops effectively captures effects of competing routes/stops • Riders may choose alternative stops, routes, destinations for pursuing activities • Need to identify and define upstream and downstream stops that can be reached using neighboring stops • Define series of stops, H1 through H5, identified by network connectivity

19. Accessible Stops: Illustration Network 1 2 3 4 Route 1 7 5 8 6 14 Route 2 14 14 14 10 9 11 12 Route 3 13 15 16 14 Route 4 Route 5 Route 7 Route 8 Route 6

20. Neighboring Stops: Illustration Network • Network • 8 routes (each two way) • 16 nodes (n=1, …, 16) • 64 stops (nX, n=1,…, 16; X=N,S,E,W) • Neighboring Stops • N1 = {2S} • N2 = {6N} • N3 = {6W, 6E} • N4 = {6W, 6E}

21. Accessible Stops: Illustration Network • H1 = {1S, 1E, 2E, 2W, 3E, 3W, 3S, 4W, 4S, 5E, 7W, 8W, 9N, 9E, 10W, 10E, 11W, 11E, 12N, 12W, 13N, 13E, 14W, 14E, 15W, 15E, 16W, 16N} • H2 = {1W, 2N, 3E, 4E, 5S, 7S, 8S, 9S, 11S, 12S, 13S, 15S, 16S} • H3 = {1N, 3N, 4N, 5N, 7N, 8N, 9W, 9N, 10S, 11E, 11N, 12E, 12N, 13S, 13W, 14S, 15E, 15S, 16E, 16S} • H4 = {1N, 1W, 2E, 2W, 3N, 3E, 3W, 4E, 4N, 5W, 5N, 7E, 8E, 9S, 10E, 10W, 11E, 11W, 12S, 12E, 13S, 13W, 14E, 14W, 15E, 15S, 15W, 16S, 16E} • H5 = {1N, 1W, 3N, 3E, 3W, 4E, 4N, 5W, 5N, 7E, 8E, 9S, 10E, 10W, 11E, 11W, 12S, 12E, 13S, 13W, 14E, 14W, 15E, 15S, 15W, 16S, 16E}

22. Defining Accessible Stops • H1 includes stops that can reach the N3 and N4 neighboring stops (Interest: boardings) • H2 includes upstream stops that can be reached from the N2 stops (Interest: buffer area) • H3 includes stops downstream that can be reached from stop in question through route serving the stop in question via the transit network (Interest: buffer area) • H4 includes stops that can be reached from the N3 and N4 neighboring stops (Interest: buffer area) • H5 includes stops in H4 that overlap with stops in H3 (Interest: overlapped area)

23. Computing Transit Accessibility • Two components of transit accessibility • Access/egress at stop in question • Accessibility from stop to all other stops in network • Access/egress at stop in question measured through simple air-distance buffer distance • Accessibility from one stop to all other stops in network uses gravity-type measure:

24. Computing Transit Accessibility • Oi is the measure(s) of accessibility included in the boarding equations • Q represents buffer characteristics of stops in H2 through H5 and boardings at stops in H1 • G represents impedance from stops in H1 and impedance to stops in H2 through H5 • b is gravity model parameter • Impedance measured by generalized cost of traveling from one stop to another

25. Computing Impedance, G • Components of impedance • First wait time • First boarding fare • In-vehicle time • Transfer wait time • Number of transfers • Transfer walking time • Transfer fare • Model sensitive to host of service characteristics

26. Components of Impedance, G Components Unit Value/Source Symbol Weight Symbol Value First-wait time Minutes Half of first headway with a cap of 30 FWT WFWT 3.0 First-boarding fare Dollars Base cash fare FBF WFBF 1/v Minutes Cumulative scheduled travel time IVL WIVL 1.0 In-vehicle-time Minutes TWT WTWT 3.0 Transfer-wait time Headway of transfer stop if no coordination and deviation if coordinated for up to two transfers Number of transfers Number Up to two NTF WNTF 5.0 Transfer-walking time Minutes Time to transfer stops at 3 mph TWK WTWK 1.5 Transfer-boarding fare Dollars Base cash fare for transfers TBF WTBF 1/v v = half of average hourly wage rate in service area

27. Model Functionality • BEST 3.0 will retain user functionality from first two generations • GIS interface for database setup and displays • Sets of default equations by time period • Automated buffering • Automated accessibility and impedance computations • Report generation including performance measures

28. Model Development • BEST 3.0 software development underway • Model estimation using APC data from Jacksonville, Florida • Using Census 2000 data for socio-economic variables • Programming accessibility and impedance computation capability at this time • Anticipated release of software in late summer or early fall

29. Conclusions • BEST 3.0 will provide a powerful framework for modeling transit ridership at stop level • Incorporates effects of accessibility and connectivity on ridership • Accessibility and impedance computations very sophisticated and accurate • More precisely accommodates effects of service span and frequency (temporal aspects) • Focus on ease of use and quick response capability