Lower Adirondack GIS Users Group Meeting

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Lower Adirondack GIS Users Group Meeting
Warren County Street Centerline
Project December 1, 2004
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Background

• Warren County
• 1200 miles of public roads
• 600 miles of private roads
• County completed in-house
• 450 miles geometry
• 200 miles attribution
• Error checking of 1 town
• Summer 2004 the Sheriffs Department hired a
  consultant, (Applied GIS, Inc.) to complete the
  project

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Existing Road Data

• NYS DOT roads
• TIGER roads
• NYS Accident Location Information System (ALIS)

These data sources have inaccuracies in geometry
and attribution (especially consistency with
E-911 address ranges)
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Data Sources for Geometry Development

• 2001 Digital Orthoimagery
• Tax Parcel layer with RPS
• Road Centerlines from ALIS
• GPS field work

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GPS used to delineated roads that were not
visible on the orthoimagery
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Geometry Methodology

• Divided Roads Line segments heads up digitized
  following the roads centerline (where visible)
• Undivided and Dirt Roads Line segments within
  the edge of the roadbed

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Geometry Methodology

• Complex Features
• Cul-de-sacs
• Multiple lane highways
• Divided highways
• Follow ALIS Project Rules

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Attribution Methodology

• Based on Warren Countys Dispatch System
• Primarily manual coding, referencing Sheriff
  Department Excel spreadsheets
• 14 fields manually entered
• Additional fields obtained from Sheriff
  Department Excel

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Attribution Methodology

• Manual Attributes Coded

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Attribution Methodology

• Address ranges interpolated from Excel data
  fields
• Cross reference with other sources
• Spreadsheets listing residents names and house
  numbers (available for half the towns)
• Real Property data (BUT! not consistently
  accurate for E-911 addresses)

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Error Checking

• Type 1 Compare Sheriff Excel spreadsheet address
  ranges to other available sources
• Error report of unresolved cases provided to
  Sheriffs Department
• Sheriffs Department field checked, corrected
  data sent back to Applied GIS for update

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Error Checking

• Type 2 Geocode in ArcGIS the Countys Voter
  Registration database for each town.
• Errors identified as either
• Mistake in address ranges of data (correction by
  consultant)
• Error in voter registration database

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Problem

• Countys address ranges were developed
  independent of GIS, therefore address ranges may
  not be consistent with road length

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Thank You!