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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 - PowerPoint PPT Presentation
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presented to
GIS Committee
presented by
Eric Songer, URS Corporation
11/20/2008
Turnpike Enterprise Use of TeleAtlas GIS Data for Transportation Modeling
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Agenda
Context
What we did
What we are doing
Where we believe we should go
Discussion
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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
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TeleAtlas Data for Transportation Modeling What We Did
Turnpike State Model
TeleAtlas “features”
Spatial/Geometry Issues
Attribute Issues
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Turnpike State Model
Statewide
County Building Blocks
Used shapefiles from TeleAtlas
Duplicate arcs removed
Chaining of arcs done in Fennessy’s software
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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
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Spatial Geometry Issues
Duplicate arcs cause headaches
Geometry links up in 3 dimensions
Does not contain every road
Does not contain future roads
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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
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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
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TeleAtlas Data for Transportation Modeling What We Are Currently Doing
Context
Versioned ESRI geodatabase
Model runs are snapshots of database
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Context
Regional Models (Lee-Collier, Central Florida)
Continual refinement of all processes
Lee-Collier complete
Central Florida being built
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Versioned ESRI Geodatabase
Personal ArcSDE (SQL Server Express)
Editors get Personal GDB (Access based)
Checked in by data administrator
No longer separate county files
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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
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Lessons Learned
Tradeoff between speed and duplication
The Devil is in the details
You are never done
It can always be better
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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
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Regular Maintenance
Get quarterly updates as Transaction Files
Automate update where appropriate
Expect we will always need to manually fix some areas
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True Geodatabase
Believe a cascading update structure can be built
Better way to store data
Spatial views
Versioning
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Archiving
Multiple dimensions to problem of archiving
Not only documentation
Need to be able to resurrect that model for future work
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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
