Georgia Department of Transportation Georgia Department of Transportation Office of Transportation DataOffice of Transportation Data

Reporting Local Centerline MileageReporting Local Centerline MileageAtlanta Regional CommissionAtlanta Regional Commission

Regional GIS User GroupRegional GIS User GroupSeptember 7, 2011 September 7, 2011

Statewide Centerline Update Project Local Centerline Mileage

In January 2011 GDOT Commissioner Vance Smith sent a letter to every one of Georgia’s

159 Counties531 Cities

Statewide Centerline Update Project Local Centerline Mileage

GDOT asked for… The total number of miles of

Local Public Roads owned by each local government; as measured by Centerline Miles

Statewide Centerline Update Project Local Centerline Mileage

Georgia Code 32-4-41(4) and 32-4-91(b)says that all Local Governments must Inform GDOT when they:

Acquire/Accept a road

or Abandon a road

Statewide Centerline Update Project Local Centerline Mileage

153 Counties (96%)and

328 Municipalities (61%)have reported

Statewide Centerline Update Project Local Centerline Mileage

GDOT is required by state law to keep this information for calculating funding levels of…

Transportation Investment Act of 2010 (TIA)

Local Maintenance Improvement Grants (LMIG)

Statewide Centerline Update Project Local Centerline Mileage

Other uses include…

Creating County maps

Certified Mileage for Federal Reporting

Updating Centerline Mileage DataUpdating Centerline Mileage Data

Statewide Centerline Update Project Project Scope

Implement New Centerline Data Model Bring Data Completely Up-to-Date By

Adding, Modifying & Removing Roads Cleanse Data - Resolve Various Issues Ensure Clean Topology Validate Local Mileage Totals Provide Data Back To Local Agencies

GDOT’s most current road centerline, bridge and railroad crossing data

Local GIS street and city/county boundary data

2010 Census TIGER street/boundary data

Orthophotography (various sources)

Statewide Centerline Update Project Source Data

Statewide Centerline Update Project Data Issues

Roads that Extend Beyond/Stop Short of County Boundary

Statewide Centerline Update Project Data Issues

Out-of-Date

The Georgia

Aquarium--

Opened 2005

The World of

Coca-Cola

Statewide Centerline Update Project Data Issues

After Updates

The Georgia

Aquarium--

Opened 2005

The World of

Coca-Cola

Statewide Centerline Update Project Data Issues

Bad Centerline Geometry

Statewide Centerline Update Project Data Issues

BEFORE

Inaccurate Geometry

Statewide Centerline Update Project Data Issues

AFTER

After Updates

Statewide Centerline Update Project Data Issues

“Unknown Roads” (Route Type = U)

Statewide Centerline Update Project Data Issues

Topological Errors (Overlapping & Intersecting Road Segments, Dangles, Pseudo-nodes)

Statewide Centerline Update Project Data Issues

Erroneous/Incomplete Ownership Assignment (County Roads, City Streets, Private Roads, Etc.)

Roads Traversing City/County Boundaries

Various RC Coding Errors

Fulton County Mileage – GDOT Data

2009 2010 GIS Difference

State Routes 415 377 -31

County Roads 1,249 592 -622

City Streets 1,796 3,213 +1,412

Statewide Centerline Update Project Fulton County Data Update

Mileage in some Fulton Cities

Statewide Centerline Update Project Data Update

AtlantaCollege Park FairburnJohns CreekMiltonRoswellSandy Springs

2009 Reported

1,6436697

251180348316

2010 GIS

1,5076599

227189354305

Difference

- 136-1+2

-24+9+6

-11

Statewide Centerline Update Project Current Project Status

5 Counties Complete 38 Counties In Progress

Statewide Centerline Update Project Primary Project Goals

Establish & Maintain Complete and Accurate Statewide Road Centerline Data Ensure Appropriate Mileages For All Local Agencies Reduce the need for field data collection Perform event-driven updates Foster A Cooperative Environment Build Working Relationships With Local Governments

Statewide Centerline Update Project How Can You Help?

Provide Digital (GIS) Street & Boundary Data; Imagery Share Street Attribute Data Assist With Identifying Road Ownership (City, County, Private, Other) Assist With Resolving Boundary Road Issues Be Available To GDOT for Consultations Via Phone, E-Mail or Face-to-Face Meetings Work With GDOT & Neighboring Agencies To Resolve

Conflicts

Statewide Centerline Update Project Q&A

Statewide Centerline Update Project Contacts

Douglas Alexander

dalexander@dot.ga.gov

770-986-1436

Michael D. Morris

mimorris@dot.ga.gov

770-986-1366