Using GIS Networks to Represent Model Networks

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Using GIS Networks to Represent Model Networks

• May 19, 2009
• Hoyt Davis Chunyu Lu
• Gannett Fleming, Inc.

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Outline

• Background Introduction

• Generating True Shape Networks in Travel Forecast
  Model

• Incorporate Into Cube Environment

• New Technology

• Questions?

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Background Introduction

• Former Florida highway model networks were
  generally stick-figured networks that show
  traffic flows from one node point to another
  using straight lines.
• The stick-figured networks usually
• Do not have to represent the highway network in a
  visually pleasing way
• Are commonly modified to allow some roadway
  curvature by breaking their network links into
  smaller pieces
• Do not incorporate full functionality from ArcGIS
  Engine and Geodatabase
• Make the highway network less efficient causing
  longer model processing times.
• The latest versions of Cube Voyager allow users
  to utilize true shape networks which use GIS
  detail accuracy in its integrated network
  environment.

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Stick-figured Network
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Background Introduction

• FDOT District 7 and District 5 have requested for
  Gannett Fleming to develop GIS-based highway
  networks for initial use in their Regional
  Planning Models.
• The new GIS-based network is expected to
• Improve the accuracy of the model in terms of
  truer GIS distances of highway facilities
• Decrease the number of highway links in the model
  networks and therefore decrease the model
  processing times
• Incorporate full functionality of the ArcGIS
  Engine and Geodatabase technology
• Provide for better integration with future
  versions of the Cube Voyager software.

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True Shape Network
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Outline

• Background Introduction

• Generating True Shape Networks in Travel Forecast
  Model

• Incorporate Into Cube Environment

• New Technology

• QA

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How Did We Get Started

• Available data resources
• State TeleAtlas/GDT roadway data
• Aerial photos
• Existing model networks
• There are two options to get started
• Start with available non-transportation base true
  shape GIS networks to clean network attributes
  and merge links or
• Start with existing model networks and realign
  network links based on true shape curvatures from
  true shape GIS networks.
• It was more efficient to start from the model
  networks and manually realign the network to true
  shape curvatures.

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Challenges

• 1 Consolidate the network from small link
  pieces
• 2 Manually match every vertex to the true shape
  curve
• 3 Incorporate the true shape network into the
  Cube environment and the model flow seamlessly.
• Solutions
• Link consolidation based on area type, facility
  type, and number of lane combination
• Link conflation tool developed using Visual Basic
  for Applications in the ArcGIS Environment
• Build Network from Shape File Tool and Cube
  script.

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Other Challenges

• Coordinate with the Department and the MPOs to
  determine all improvements to the highway system
  between existing network and the new base year
  network.
• More network attributes were required to be
  added
• Posted Speed
• Count Sources and Count Station ID
• Local /MPO/ County Screenlines
• Highway network support file development
  included
• Toll link file
• Time penalty and turn prohibitor file
• Transit station file
• Use Cube scripting to develop a process to
  convert the GIS network shape file to a model
  network.

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Link Consolidation
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Geometry Conflation Tool
Target GDT Layer
Model Network
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Select Nodes for Shortest Path
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Run Shortest Path
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Geometry Conflation
Link Match
Node Match
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Link Direction vs. Two-way Attribute
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New Roadway Attributes

• Road Name and Alternative Road Name
• Posted Speed
• Traffic Count Sources and Station ID
• Local/County/MPO Screenlines
• Roadway Label and Number
• Federal Functional Classification code

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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

• The true shape network means new features
• Specify external and dummy centroids
• Node renumbering by County
• Node number sorted by X and Y coordinates
• Highway links and centroid connectors summary by
  County

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Outline

• Background Introduction

• Generating True Shape Networks in Travel Forecast
  Model

• Incorporate Into Cube Environment

• New Technology

• QA

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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

• Add Highway Links
• Copy links attributes
• Update node number
• Move Links
• Node snapping
• Update node number
• Link direction
• Delete Links
• Link Split

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Transit Network in Cube
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Edit Transit Network
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Outline

• Background Introduction

• Generating True Shape Networks in Travel Forecast
  Model

• Incorporate Into Cube Environment

• New Technology

• QA

32
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Outline

• Background Introduction

• Generating True Shape Networks in Travel Forecast
  Model

• Incorporate Into Cube Environment

• New Technology

• QA