North Carolina’s New Statewide Road Centerline Data

Sarah Wray, GISP, CGCIO Tim Sheldon, GISP

Spatial Data Manager Business Analyst

Engineering Transportation Systems – GIS Unit Timmons Group

sbwray@ncdot.gov tim.sheldon@timmons.com

The New Statewide Centerline Data• All public roads

• Authoritative sources:• NCDOT • Local governments

• One state schema• Topologically correct

• including political boundary lines

Why, you ask?• Various centerline maintenance across the state

• NCDOT maintains system route geometries• Local Governments maintain geometries for both

• NCDOT system and Non-System routes

• Federal Reporting Requirements• Source standardization for all federal agencies• $$ Funding $$

• Planning Support• Strategic prioritization of projects

Currently

Stove Pipe Data• NCDOT Authoritative Data• Local Government Authoritative

Data• Governments are willing to share,

but that only goes part way

Schema and Topological Inconsistencies

• 101 Schemas• 100 Local Government• 1 NCDOT Statewide

• Topologies Internal to a source dataset• Neighboring counties don’t necessarily have to connect

centerlines at county boundaries• NCDOT & Non-NCDOT maintained centerlines

Predecessors• Local Government efforts• ISRN• Carbon Project

ISRN – November 2007

• NCDOT Integrated Statewide Road Network • Constructed from multiple sources

• 2005 TIGER• County data

• Not maintained

Carbon Project – November 2012

• Work by the Working Group for Roads and Transportation• Exists to facilitate the sharing of roads data between regional

planning organizations, local governments, state agencies, and the public.

• Web based schema mapping tool• Allows registered local representatives to upload and schema-map

their data

• NCDOT owns the translator• Contains 82 of NC’s 100 counties of centerline data

Rome – September 2015 ??

NCDOT’s project to implement Esri’s Roads and Highways Linear Referencing Solution

• Upgraded enterprise LRS• Centerline data for the Rome project began around

September 2013• NCDOT sponsored• Permanent Staff• Contract staff• Software Vendors

Rome Project Data Sources

• Local Governments• From NCDOT data collection processes

• Data collected by an analyst at NCDOT approx. once every 6 months

• In place of Carbon Project to ensure data availability for project go-live

• NCDOT• From NCDOT Production LRS as of 1/6/2015

• LRS is currently frozen for maintenance pending Rome go-live

Rome Project High Level Methodology (Non-System)• Research 100 local government schemas

• Data as collected by NCDOT process

• Evaluate Local Government Information Model (LGIM)• Eligible to participate in Esri’s Community Maps program• Necessary items to maximize usefulness of data

• Choose dominant items from 100 schemas and LGIM• Created a data model to be used as a basis for migration

100 ETLs Created – Maintained by NCDOT

Rome Project High Level Methodology (System)• NCDOT Source LRS

• Daily maintenance• Downstream Business Continuity• Legacy Routes

• Advanced Linear Referencing Minimum Schema• Items from NCDOT LRS

• Routes• Centerlines

Rome Data Model

NCDOT System & Non-System Integration

• Authoritative sources• Remove non authoritative spatial overlaps

• Topology• Connect NCDOT system with non-system

• Conflation• Move desired attributes from non-system routes to system

routes• i.e. Street Name

NC One Centerline Conflation Process

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Ongoing Maintenance

• G1FTSEG Legacy Reference Data• NCDOT Data Conversion and Event Editors• Daily update of system (NCDOT) centerlines• Quarterly update of non-system centerlines

• Schedule and methodology pending completion of Rome project• Local government centerlines may come from Carbon Project or

through existing data collection efforts by NCDOT.• Change detection process

How does the general public get the data?

• Publication Web Services as part of the Rome project• Go!NC – NCDOT’s ArcGIS On Line implementation• http://ncdot.maps.arcgis.com

• NCDOT Data Distribution Web Page • Minimum quarterly• https://connect.ncdot.gov/resources/gis/Pages/GIS-Data-Layers.aspx

What’s Next for the Data• What will NCDOT do with the data?

• Maintain as the enterprise LRS• FHWA requirements

• What can other state agencies do with the data?• Addressing as event data along the LRS• Inclusion of State Park, Federal and Wildlife Resources

Commission data

• What can local governments do with the data?• Choose to consume as source data• Addressing, public works

North Carolina’s New Statewide Road Centerline Data

Sarah Wray, GISP, CGCIO Tim Sheldon, GISP

Spatial Data Manager Business Analyst

Engineering Transportation Systems – GIS Unit Timmons Group

sbwray@ncdot.gov tim.sheldon@timmons.com