Adding Value to Travel Behavior Surveys:: Adding Value to Travel Behavior Surveys: Presentation by: Kearey L. Smith Stella Wotherspoon Metropolitan Transportation Commission San Francisco Bay Area, CA ESRI User Conference 2006 San Diego, CA August 10, 2006 The Network Analyst Approach


Bay Area Travel Survey 2000: Bay Area Travel Survey 2000 Regional household travel survey of the nine-county SF Bay Area Activity-based reporting to capture all trips during study period ~15,000 household respondents ~ 229,000 intra-regional trips Used for travel demand modeling and forecasting


Goal for Extended GIS Analysis: Goal for Extended GIS Analysis To derive several new variables based upon precise home and work locations of survey respondents. Move away from past analyses which are zone-based Network Analyst 9.1 adds important tools to assist analysts with the development of new travel behavior models New variables add significant value to the travel survey


Primary Objectives for Extended GIS Analysis: Primary Objectives for Extended GIS Analysis Geocode all household and trip end locations from the survey Append Standard Census Bureau and MTC Geography Build Multi-modal Network Dataset Derive Door to Door distances and time Derive the walk distance to the closest transit stop(s)


Primary Objectives for Extended GIS Analysis: Primary Objectives for Extended GIS Analysis Find stops that are within ¼, ½, and 1 mile walking distance from all households Derive population and employment characteristics of all households and transit stops used in the study


Primary GIS Tools Used to Conduct the Analyses : Primary GIS Tools Used to Conduct the Analyses Arcmap Tools Geocoding Spatial Joins Network Analyst Tools Build Network & Calculate Network Locations Find Best Route Origin and Destination Cost Matrix Service Area Tool Spatial Analyst Tools Zonal Statistics


Build Network Dataset: Build Network Dataset A network dataset is the file set used by Network Analyst 9.1 to calculate routes and service areas, to locate closest facilities, and to produce origin-destination matrices Used the TeleAtlas North America (TANA) Dynamap Transportation Database Added Pedestrian Facilities for areas where none exist in the TANA Dynamap database Can be as a shapefile or geodatabase feature class


Build Network Dataset: Build Network Dataset Topology is crucially important


Calculate Network Locations: Calculate Network Locations Once this is done, tools will load locations quickly to the analysis layer Ensure that locations are assigned to pedestrian accessible line segments


Make Route Layer: Make Route Layer Derive the door to door distance and estimated time for over 229,000 trip records Developed a custom visual basic script that automates the calculation of each origin and destination trip pair


Origin and Destination Cost Matrix : Origin and Destination Cost Matrix Derive the walk distance to the closet transit stop and the drive distance to the nearest transit park and ride facility Very large Matrices require preprocessing of data


Find Service Area : Find Service Area Create pedestrian buffers for all rail and ferry stops in the region The result of this process was used in a spatial model to estimate total population and jobs


Estimating Population and Employment Characteristics: Estimating Population and Employment Characteristics A method had to be devised that accommodates the different shapes of the census tracts and the pedestrian buffers. The Zonal function tools in Spatial Analyst can summarize a value raster based upon a zone defined by a polygon feature class. The value raster is created using Census Tract data and Existing Land Use


Zonal Statistics : Zonal Statistics Determine Population and Employment characteristics for each household and transit stop location in the survey Developed a spatial model using Python scripting to automate the zonal statistic tabulation process


Next Steps: Next Steps Add Transit System as a Mode Choice Measure Pedestrian Accessibility of each transit stop Classify Transit Stops based upon the General Land Use Characteristics around each station location


Adding Value to Travel Behavior Surveys: Adding Value to Travel Behavior Surveys More Information Download this presentation and report, as well as other info. from our Website @ http://www.mtc.ca.gov/maps_and_data/GIS/soundbytes.htm Check out the Network Modeling and Analysis Section


Adding Value to Travel Behavior Surveys: Adding Value to Travel Behavior Surveys Contact Information Metropolitan Transportation Commission 101 Eighth Street Oakland, CA 94607 www.mtc.ca.gov Mr. Kearey Smith ksmith@mtc.ca.gov 510-817-5738 Ms. Stella Wotherspoon swothe@mtc.ca.gov 510-817-5969