Improving Iowa

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Improving Iowas Road Centerline Databases

• Bill Schuman, GIS Coordinator
• Karen Carroll, Transportation Data

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Session Outline

• Linear Referencing System
• What is a linear referencing system?
• LRS Core Components
• LRS Maintenance Application
• Geographic Information Information System (GIMS)
  Redesign
• Decision Support Environment
• What is a Decision Support Environment?
• Oklahoma DOT GRIP Demonstration

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Session Outline

• Linear Referencing System
• What is a linear referencing system?
• LRS Core Components
• LRS Maintenance Application
• Geographic Information Information System (GIMS)
  Redesign
• Decision Support Environment
• What is a Decision Support Environment?
• Oklahoma DOT GRIP Demonstration

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Linear GIS Data Models Special Problems in
Linear GIS
Business Data
Cartographic Representation
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Linear GIS Data Models Different Approaches

• Fixed length segments
• All segments the same length
• Must summarize data very redundant
• Variable length segments
• Segment determined by unique sections
• Some summarization redundancy
• No segments / dynamic segmentation
• Minimizes redundancy
• More database tables

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Linear GIS Data Models Fixed Segment Length
Business Data
0.1 mi
0.1 mi
Cartographic Representation
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Linear GIS Data Models Variable Segment Length
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Linear GIS Data Models Dynamic Segmentation
Analysis
Pavement Type
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What does Iowa need to do?
How do we keep our data current?
Do we need more accuracy?
How do we develop a linear network?
What linear data model should we use?
What do our customers need?
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Meeting the NeedsIowa DOTs Approach to Problem

• Created a team to make recommendations to DOT
  management
• Researched state of practice
• Looked at accepted processes/systems
• Looked at new processes/systems
• Inventoried current linear location methods used
  in Iowa
• Investigated linear location needs of Iowas data
  users
• General recommendation Develop a Linear
  Reference System (LRS)

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LRS Core ComponentsFundamental Definitions

• LRS - Linear Referencing System
• A set of procedures and methods for specifying a
  location as a distance, or offset, along a linear
  feature, from a point with known location.
• A LRS can relate a linear location (1D) to a
  spatial (2D) location through a centerline
  representation of the roadway.
• LRM - Linear Referencing Method
• Different methods of measuring locations (i.e.
  milepost, literal descriptions, stations, address
  ranges, etc.).
• A LRM is part of the LRS.

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LRS Core Components The Teams Recommendations

• Need to improve spatial representation of the
  road centerlines
• Use NCHRP (20-27) project model
• Need ability to integrate variety of data
• Mile post referenced data (US 30 _at_ 135.23)
• Coordinate referenced data (Lat, Long, I35)
• Literal description data (2.51 mi past 1st St)
• Road address data (247 E. Main St)
• Establish maintenance processes and partnerships

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LRS Core Components Simplified Visual
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LRS Core Components Simplified Visual
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LRS Core Components Statewide Data Collection
Effort

• Centerline collection complete for all
  Interstate, US, and State roads
• Eight counties collected
• Collected from best image source available

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LRS Core Components Local Roads in LRS

• Four counties
• All primary roads completed by end of FY03
• 28E Agreement with City of Des Moines
• Agree to maintain street centerlines
• 50,000 to LRS

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LRS Core Components Comparison of Centerlines
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LRS Core Components Feature Association
Cartographic Representation
Datum
Network
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LRS Core Components Maintenance Application

• Maintains the data in the LRS database
• Constructed on commercially available products
• GeoMedia (Professional Transaction Mgr)
• Oracle (Core, Spatial, Workspace Mgr)
• Location Data Manager Extensions (LDMx)
• Three-tier architecture
• Contains a change propagation engine, quality
  control checker, and temporal data management

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LRS Core Components Maintenance Application
Architecture
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LRS Core Components Maintenance Application
Architecture
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LRS Core Components Maintenance Application
Architecture
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LRS Core Components Maintenance
Application-Change Tracking
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LRS Core Components Maintenance
Application-Metadata
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LRS Core Components Maintenance
Application-Conflation
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LRS Core Components Maintenance
Application-Conflation
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LRS Core Components Maintenance
Application-Conflation
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LRS Core Components Maintenance
Application-Quality Control
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LRS Core Components Maintenance
Application-Routes
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LRS Core Components Maintenance
Application-Temporal
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LRS Core Components Maintenance
Application-Temporal
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LRS Core Components Maintenance
Application-Temporal
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LRS Core ComponentsConclusions

• LRS Purposes
• Ability to integrate plethora of data
• Remain scalable for future needs
• Provide a comprehensive transportation GIS
• LRS Maintenance Application
• Make it easy to maintain a fairly complex
  database
• Provide good metadata and history for the road
  network
• Always ensures a quality database

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Session Outline

• Linear Referencing System
• What is a linear referencing system?
• LRS Core Components
• LRS Maintenance Application
• Geographic Information Information System (GIMS)
  Redesign
• Decision Support Environment
• What is a Decision Support Environment?
• Oklahoma DOT GRIP Demonstration

36
Session Outline

• Linear Referencing System
• What is a linear referencing system?
• LRS Core Components
• LRS Maintenance Application
• Geographic Information Information System (GIMS)
  Redesign
• Decision Support Environment
• What is a Decision Support Environment?
• Oklahoma DOT GRIP Demonstration

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Decision Support Environment System Architecture
for Integrating Data
LRS Maintainer
GIS Maintainer
General Decision Support
Web CTAMS
Linear Business Data
GeoData Library
Crash Records
LRS
GIS
CTAMS
Bridge
Specific Analysis Systems
Staging Process
PMIS
Derived Data Values from Integrated Data
PMIS
GIMS
Derived Data Values from Integrated Data
Sufficiency
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Decision Support Environment Iowa DOT CTAMS
Project
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Decision Support Environment Iowa DOT CTAMS
Project
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Decision Support Environment Oklahoma DOT GRIP
Project
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Decision Support Environment Oklahoma DOT GRIP
Project
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Decision Support Environment Oklahoma DOT GRIP
Project
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Decision Support Environment Iowa DOT ERMS/GIS
Integration Project
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Decision Support Environment Oklahoma DOT GRIP
Project
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Decision Support Environment Oklahoma DOT GRIP
Project
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Session Outline

• Linear Referencing System
• What is a linear referencing system?
• LRS Core Components
• LRS Maintenance Application
• Geographic Information Information System (GIMS)
  Redesign
• Decision Support Environment
• What is a Decision Support Environment?
• Oklahoma DOT GRIP Demonstration

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Presentation Wrap-up Benefits of the LRS -
Opportunities for Savings

• Provides a centralized data source for most road
  transportation information systems
• Minimizes redundancy
• City Government (Utilities, Engineering)
• County Government (Engineering, Assessor)
• State Government (DOT, Emergency Mgmt)
• Federal Government (Census, FHWA)
• Expend resources to provide more extensive and
  accurate data, rather than similar copies
• Benefits homeland security and emergency
  management
• Share maintenance effort

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Additional Information

• Presentation available at
• www.iowadotmaps.com
• Click on the Links pulldown
• Pens have web page printed on side
• New 2004 Transportation Map!
• Just released today!

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Questions
?