1 / 48

Improving Iowa’s Road Centerline Databases

Improving Iowa’s Road Centerline Databases. Bill Schuman, GIS Coordinator Karen Carroll, Transportation Data. Session Outline. Linear Referencing System What is a linear referencing system? LRS Core Components LRS Maintenance Application

penda
Download Presentation

Improving Iowa’s Road Centerline Databases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Improving Iowa’s Road Centerline Databases Bill Schuman, GIS Coordinator Karen Carroll, Transportation Data

  2. 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

  3. 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

  4. Linear GIS Data Models Special Problems in Linear GIS Business Data Cartographic Representation

  5. 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

  6. Linear GIS Data Models Fixed Segment Length Business Data 0.1 mi 0.1 mi Cartographic Representation

  7. road_info structure city_info guard_rail Main Street road_name pavement_type no_of_vehicles jurisdiction road_name pavement_type no_of_vehicles jurisdiction guard_rail road_name pavement_type no_of_vehicles road_name pavement_type no_of_vehicles jurisdiction guard_rail structure road_name road_name pavement_type Concrete Asphalt 2500 500 City A City B Linear GIS Data Models Variable Segment Length

  8. 0 0.5 2.3 4.8 35 45 55 Speed Limit 0 2.5 30000 22000 AADT Values 0 4.1 5.2 Concrete Asphalt Asphalt 0 0.2 2.1 5.8 30 34 32 Friction Linear Query Results 2.5 4.1 5.2 5.8 where: Speed => 45 AADT < 25000 Pavement = Asphalt Friction =< 30 Linear GIS Data Models Dynamic Segmentation Analysis Pavement Type

  9. 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?

  10. Meeting the NeedsIowa DOT’s 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 Iowa’s data users • General recommendation: Develop a Linear Reference System (LRS)

  11. 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.

  12. LRS Core Components The Team’s 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 @ 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

  13. Base Record Inventory Project Data Program Crash PMIS Coordinate Route Reference Post GIMS Segmental Milepoint Stationing Literal Description LRS Core Components Simplified Visual

  14. Base Record Inventory Project Data Program Crash PMIS Coordinate Route Reference Post GIMS Segmental Milepoint Stationing Literal Description LRS Components Address Range Centerline Representation 1 Centerline Representation 2 Centerline Representation 3 LRS Core Components Simplified Visual

  15. 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

  16. 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

  17. LRS Core Components Comparison of Centerlines

  18. %AS %AS LRSx Conflation Object LRSx Conflation Object %AS %AS %AS %AS %AS %AS LRS Core Components Feature Association Cartographic Representation Datum Network

  19. 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

  20. LRS Core Components Maintenance Application Architecture

  21. LRS Core Components Maintenance Application Architecture

  22. LRS Core Components Maintenance Application Architecture

  23. LRS Core Components Maintenance Application-Change Tracking

  24. LRS Core Components Maintenance Application-Metadata

  25. LRS Core Components Maintenance Application-Conflation

  26. LRS Core Components Maintenance Application-Conflation

  27. LRS Core Components Maintenance Application-Conflation

  28. LRS Core Components Maintenance Application-Quality Control

  29. LRS Core Components Maintenance Application-Routes

  30. LRS Core Components Maintenance Application-Temporal

  31. LRS Core Components Maintenance Application-Temporal

  32. LRS Core Components Maintenance Application-Temporal

  33. 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

  34. 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

  35. 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. 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

  37. Decision Support Environment Iowa DOT CTAMS Project

  38. Decision Support Environment Iowa DOT CTAMS Project

  39. Decision Support Environment Oklahoma DOT GRIP Project

  40. Decision Support Environment Oklahoma DOT GRIP Project

  41. Decision Support Environment Iowa DOT ERMS/GIS Integration Project

  42. Decision Support Environment Oklahoma DOT GRIP Project

  43. Decision Support Environment Oklahoma DOT GRIP Project

  44. 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

  45. 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

  46. 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!

  47. Questions ?

More Related