using gis networks to represent model networks may 19, 2009 hoyt davis & chunyu lu gannett...
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Using GIS Networks to Represent Model Networks
May 19, 2009May 19, 2009
Hoyt Davis & Chunyu LuHoyt Davis & Chunyu Lu
Gannett Fleming, Inc.Gannett Fleming, Inc.
Outline
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Background IntroductionBackground Introduction
Generating True Shape Networks in Travel Generating True Shape Networks in Travel Forecast Model Forecast Model
Incorporate Into Cube EnvironmentIncorporate Into Cube Environment
New Technology New Technology
Questions? Questions?
Background Introduction
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Former Florida highway model networks were Former Florida highway model networks were generally “stick-figured” networks that show generally “stick-figured” networks that show traffic flows from one node point to another using traffic flows from one node point to another using straight lines.straight lines.
The “stick-figured” networks usually:The “stick-figured” networks usually: Do not have to represent the highway network in a Do not have to represent the highway network in a
visually pleasing way;visually pleasing way; Are commonly modified to allow some roadway curvature Are commonly modified to allow some roadway curvature
by breaking their network links into smaller pieces;by breaking their network links into smaller pieces; Do not incorporate full functionality from ArcGIS Engine Do not incorporate full functionality from ArcGIS Engine
and Geodatabase;and Geodatabase; Make the highway network less efficient causing longer Make the highway network less efficient causing longer
model processing times.model processing times. The latest versions of Cube Voyager allow users to utilize The latest versions of Cube Voyager allow users to utilize
true shape networks which use GIS detail accuracy in its true shape networks which use GIS detail accuracy in its integrated network environment.integrated network environment.
“Stick-figured” Network
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Background Introduction
FDOT District 7 and District 5 have requested for FDOT District 7 and District 5 have requested for Gannett Fleming to develop GIS-based highway Gannett Fleming to develop GIS-based highway networks for initial use in their Regional Planning networks for initial use in their Regional Planning Models.Models.
The new GIS-based network is expected to:The new GIS-based network is expected to: Improve the accuracy of the model in terms of truer GIS Improve the accuracy of the model in terms of truer GIS
distances of highway facilities;distances of highway facilities; Decrease the number of highway links in the model networks Decrease the number of highway links in the model networks
and therefore decrease the model processing times;and therefore decrease the model processing times; Incorporate full functionality of the ArcGIS Engine and Incorporate full functionality of the ArcGIS Engine and
Geodatabase technology;Geodatabase technology; Provide for better integration with future versions of the Provide for better integration with future versions of the
Cube Voyager software.Cube Voyager software.
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True Shape Network
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Outline
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Background IntroductionBackground Introduction
Generating True Shape Networks in Travel Generating True Shape Networks in Travel Forecast Model Forecast Model
Incorporate Into Cube EnvironmentIncorporate Into Cube Environment
New Technology New Technology
Q&AQ&A
How Did We Get Started…
Available data resources: Available data resources: State TeleAtlas/GDT roadway dataState TeleAtlas/GDT roadway data Aerial photosAerial photos Existing model networksExisting model networks
There are two options to get started:There are two options to get started: Start with available non-transportation base true shape GIS Start with available non-transportation base true shape GIS
networks to clean network attributes and merge links; ornetworks to clean network attributes and merge links; or Start with existing model networks and realign network links Start with existing model networks and realign network links
based on true shape curvatures from true shape GIS based on true shape curvatures from true shape GIS networks.networks.
It was more efficient to start from the model It was more efficient to start from the model networks and manually realign the network to true networks and manually realign the network to true shape curvatures.shape curvatures.
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Challenges
#1: Consolidate the network from small link pieces;#1: Consolidate the network from small link pieces; #2: Manually match every vertex to the true shape #2: Manually match every vertex to the true shape
curve;curve; #3: Incorporate the true shape network into the #3: Incorporate the true shape network into the
Cube environment and the model flow seamlessly.Cube environment and the model flow seamlessly.
Solutions:Solutions: Link consolidation based on area type, facility type, Link consolidation based on area type, facility type,
and number of lane combination;and number of lane combination; Link conflation tool developed using Visual Basic for Link conflation tool developed using Visual Basic for
Applications in the ArcGIS Environment;Applications in the ArcGIS Environment; ““Build Network from Shape File” Tool and Cube Build Network from Shape File” Tool and Cube
script.script.9
Other Challenges
Coordinate with the Department and the MPOs to Coordinate with the Department and the MPOs to determine all improvements to the highway system determine all improvements to the highway system between existing network and the new base year network.between existing network and the new base year network.
More network attributes were required to be added:More network attributes were required to be added: Posted SpeedPosted Speed Count Sources and Count Station IDCount Sources and Count Station ID Local /MPO/ County ScreenlinesLocal /MPO/ County Screenlines
Highway network support file development included:Highway network support file development included: Toll link fileToll link file Time penalty and turn prohibitor fileTime penalty and turn prohibitor file Transit station fileTransit station file
Use Cube scripting to develop a process to convert the GIS Use Cube scripting to develop a process to convert the GIS network shape file to a model network.network shape file to a model network.
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Link Consolidation
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Geometry Conflation Tool
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Target: GDT Layer
Model Network
Select Nodes for Shortest Path
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Run Shortest Path
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Geometry Conflation
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Link Match
Node Match
Link Direction vs. Two-way Attribute
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New Roadway Attributes
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Road Name and Alternative Road NameRoad Name and Alternative Road Name Posted SpeedPosted Speed Traffic Count Sources and Station IDTraffic Count Sources and Station ID Local/County/MPO ScreenlinesLocal/County/MPO Screenlines Roadway Label and NumberRoadway Label and Number Federal Functional Classification codeFederal Functional Classification code
Road Names and Number of Lanes
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Federal Functional Classification
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Network Link Data Dictionary
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Renumber Highway Nodes
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Highway Links and Nodes by County
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The true shape network means new features:The true shape network means new features: Specify external and dummy centroidsSpecify external and dummy centroids Node renumbering by CountyNode renumbering by County Node number sorted by X and Y coordinatesNode number sorted by X and Y coordinates Highway links and centroid connectors Highway links and centroid connectors
summary by Countysummary by County
Outline
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Background IntroductionBackground Introduction
Generating True Shape Networks in Travel Generating True Shape Networks in Travel Forecast Model Forecast Model
Incorporate Into Cube EnvironmentIncorporate Into Cube Environment
New Technology New Technology
Q&AQ&A
Build Cube Network from True Shape
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Script in Cube Voyager
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Geodatabase Manager in Cube
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True Shape Highway Network
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Edit Highway Links in Cube
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Add Highway LinksAdd Highway Links Copy links Copy links
attributesattributes Update node Update node
numbernumber Move LinksMove Links
Node snappingNode snapping Update node Update node
numbernumber Link directionLink direction
Delete LinksDelete Links Link SplitLink Split
Transit Network in Cube
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Edit Transit Network
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Outline
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Background IntroductionBackground Introduction
Generating True Shape Networks in Travel Generating True Shape Networks in Travel Forecast Model Forecast Model
Incorporate Into Cube EnvironmentIncorporate Into Cube Environment
New Technology New Technology
Q&AQ&A
Outline
33
Background IntroductionBackground Introduction
Generating True Shape Networks in Travel Generating True Shape Networks in Travel Forecast Model Forecast Model
Incorporate Into Cube EnvironmentIncorporate Into Cube Environment
New Technology New Technology
Q&AQ&A