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Turnpike Enterprise Use of TeleAtlas GIS Data for Transportation Modeling. presented to GIS Committee presented by Eric Songer, URS Corporation 11/20/2008. Agenda. Context What we did What we are doing Where we believe we should go Discussion. Context. “Data Driven” Approach
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Turnpike Enterprise Use of TeleAtlas GIS Data for Transportation Modeling presented toGIS Committee presented byEric Songer, URS Corporation 11/20/2008
Agenda • Context • What we did • What we are doing • Where we believe we should go • Discussion
Context • “Data Driven” Approach • GIS database is key • Start with best available data • Refine and constantly correct data • Modelers and GIS Analysts work closely • Hand off point is fluid • Modelers use ArcGIS to edit database
TeleAtlas Data for Transportation Modeling What We Did • Turnpike State Model • TeleAtlas “features” • Spatial/Geometry Issues • Attribute Issues
Turnpike State Model • Statewide • County Building Blocks • Used shapefiles from TeleAtlas • Duplicate arcs removed • Chaining of arcs done in Fennessy’s software
TeleAtlas “Features” • Duplicate arcs to represent multiple names • County basis has duplicate arcs between counties • Attribute fields not needed for modeling • Attributes needed for modeling • Unique ID field Dynamap_ID
Spatial Geometry Issues • Duplicate arcs cause headaches • Geometry links up in 3 dimensions • Does not contain every road • Does not contain future roads
Attribute Issues • Occasional errors (don’t assume they’re correct) • FZLEV or TZLEV = -9 are duplicate arcs • Does not have capacity, counts, and network identification • Has address and labeling information
Lessons Learned • Separate county files are logistic problem • Never missed duplicate arcs or discarded fields • Need to have capability to “Check in” numerous editors versions • Maintenance, Maintenance, Maintenance… • Can’t rely on anybody’s data “as is” or you will be wrong • Modelers can edit in ArcGIS with little training
TeleAtlas Data for Transportation Modeling What We Are Currently Doing • Context • Versioned ESRI geodatabase • Model runs are snapshots of database
Context • Regional Models (Lee-Collier, Central Florida) • Continual refinement of all processes • Lee-Collier complete • Central Florida being built
Versioned ESRI Geodatabase • Personal ArcSDE (SQL Server Express) • Editors get Personal GDB (Access based) • Checked in by data administrator • No longer separate county files
Model Run Snapshots • Shapefile is exported for input to model • Separate shapefiles for Existing and Future conditions • Shapefile and associated model files can be archived
Lessons Learned • Tradeoff between speed and duplication • The Devil is in the details • You are never done • It can always be better
TeleAtlas Data for Transportation Modeling Where we are going • Routine Maintenance of Data • Regular Updates of TeleAtlas • Transaction File • Many small updates • True Geodatabase or Route System Basis • Finished Models are Archived as Snapshots/Versions
Regular Maintenance • Get quarterly updates as Transaction Files • Automate update where appropriate • Expect we will always need to manually fix some areas
True Geodatabase • Believe a cascading update structure can be built • Better way to store data • Spatial views • Versioning
Archiving • Multiple dimensions to problem of archiving • Not only documentation • Need to be able to resurrect that model for future work
Food for Thought • Arcs must be “Chained” • Doesn’t need to be done in model software • Data Driven and Model Centric approaches both have tradeoffs • Data side is constantly being updated by third party
Questions ? Eric Songer 850-402-6327 eric_songer@urscorp.com