GIS Applications for Origin-Destination Surveys

1. GIS Applications for Origin-Destination Surveys Greg Spitz and John Lobb Resource Systems Group gspitz@rsginc.com jlobb@rsginc.com Daniel Jacobs MTA Bridges & Tunnels Wayne Bennion Wasatch Front Regional Council

2. Origin-Destination (OD) Data • Critical basis of knowledge for transportation operations, modeling, and future planning • Essential for all transportation modes • Often collected by DOTs and transit agencies, but not (yet) often analyzed with GIS • OD data are inherently spatial, and visualization is key to understand them, thus the need for GIS

3. Origin & Destination Surveys • Provide insights to: • Who the customers are • Why customers are traveling • How long they are traveling, and • Where they are traveling, etc. • Labor intensive data collection efforts • Used to understand current demand and plan for future demand • Critical data for calibrating travel models

4. GIS Tools in action • MTA Bridges and Tunnels— largest toll agency in US • Wasatch Front Regional Council &Utah Transit Authority— transit on-board survey • Two different agencies, modes, and application purposes • GIS the common denominator to solve issues for these different purposes

5. 2004 MTA B&T Origin & Destination Survey • Conducted roughly every 8-10 years • 2004 Study: • 304,000 surveys distributed in CASH lanes • 329,000 surveys mailed to E-ZPass customers • Control Data collected in both CASH and E-ZPass lanes with Pocket-PCs • E-ZPass sample from B&T, PANYNJ, NYSTA, NYSBA, and NJRSC comprising 99% of all transactions • Survey period 6AM to Midnight; Weekday, Saturday, and Sunday

6. MTA B&T Survey TAZ Structure • All zones are based on zip codes • Geocoding of survey data only necessary to the zip code level • Aggregations of zones used to form “super zones”

7. GIS using static maps • Static analysis with better presentation • Easy to put together quickly • Becoming more and more typical

8. Survey Zone Map: Close-up DRAFT

9. Super Zone Map

10. All O-D pairs with greater than 4% of traffic • All payment types • Weekday • Truck/taxi trips excluded • 6am to Midnight • Total Auto Traffic (6AM to Midnight) is 47,030 • 95% Confidence interval for these OD pairs is plus or minus 2.0% 10.2% 10.2% 19.1% 4.5% 20.2% 4.1% Example of Static Map using super zones:Bronx-Whitestone Bridge – Bronx Bound

11. GIS Tool Purpose • Take geospatial data and make it easier to visualize, analyze, and interpret • Allow more in depth analyses beyond static reports • Make the tool easy to use, so even a (skilled) monkey can use it • Leverage GIS experts’ skills without taking too much of their time

12. How was the tool made? • ArcMap extension • Access DB backend • Currently developed to be a stand alone tool (could be made to be network/web enabled) • Simple user interface created using VB development environment

13. Income Distributions by Origin Zones

14. Vehicle Occupancy by Origin Zone

15. Specific Trip Analysis

16. Travel Pattern Analysis

17. 2006 WFRC On-Board Transit Survey • 3 surveys conducted in last 15 years • Data primarily used for travel model development and forecast refinement • 2006 survey • Surveyed riders on 90 bus routes and the TRAX rail system • Collected 5,600 surveys

18. OD Data Mining is Cumbersome • Survey database has over 100 columns and 5600 rows (difficult to view all relevant variables at once) • TAZ number and/or address text may not be immediately recognizable (data is spatial)

19. GIS Tool Purpose (WFRC) • Preliminary review of the data suggested that the 2006 survey transfer rates were unreasonable • Interest in examining individual survey records efficiently

20. Goals Local QA/QC Efficiently examine each record Easy data editing/entry Gain confidence in the data used for model calibration (e.g. transfer rates) Features Custom ArcGIS application Visualize transit path details for one record at a time Routes Origin/Destination Boarding/Alighting Data viewing/editing window GIS tool (WFRC)

21. Screen capture of GIS Tool Reported data

22. Survey Errors Identified • People reported multiple paths they sometimes take, rather than simply their current path (question 7) • Inconsistency between routes and OD pair • Geocoding errors • Illogical route sequence

23. Example of Multiple Paths between same OD Pair

24. Another example of multiple paths between same OD pair

25. Summary • Application clearly identified obvious inconsistencies and errors, resulting in a more reliable database. • Visualization of these records would also be extremely helpful in assessing survey design and reducing respondent error.

26. User-friendly GIS tools developed for planners and analysts • GIS tools allow planners and others to drill down on the data • Tool interface confines the problem (both a good and bad thing) • Interface makes analysis much easier and doesn’t require in-depth software/data knowledge • Tools allow analysts to get more out of their data collection investment

27. Questions ? • Please use the Microphone.