Enterprise Centerline Data Metro Nashville Public Works

Enterprise Centerline Data & Metro Nashville Public Works Mr. Donald Reid, Paving and ROW Operations Manager, Metro Nashville Public Works donald. reid@nashville. gov Jeff Deason, GIS & IT Services Manager, Collier Engineering Co. , Inc. jeff. deason@collierengineering. com

Our Presentation Covers 3 Main Topics • The Enterprise-wide Availability of GIS Data Representing the Metro Nashville – Davidson County Roadway Network. • The Use of Centerline (CL) Data within the Metro Public Works Long-Term Pavement Preservation Program & Across MPW. • The Relationship Between These MPW Programs & the Continual Improvement of the Enterprise Dataset.

The Enterprise-wide Availability of GIS Data Representing the Metro Nashville – Davidson County Roadway Network • Access and stewardship of the enterprise CL data resource in the Metropolitan Government of Nashville & Davidson County is distributed among several departments for multiple uses. • Distributed access to the live CL data is provided through ESRI Arc. SDE from the Metro Nashville Planning Department. • Good communication between departments results in workable access agreements and fosters continual improvement to the usefulness and accuracy of the street data.

CL Data Access Options • Metro employees can access the “live” CLs by connecting to a geodatabase feature class being served through ESRI Arc. SDE in Metro Planning. • Employees can refer to the Planning section of the nashville. gov web site for search, view, pan, zoom. • Employees can work with shapefile or personal geodatabase “snapshots” of the live street data, if required.

“Live” CL Access Through Planning’s Geodatabase • “Up” Side: Most Accurate Reference • “Down” Sides: – Multiple Potential Choke Points • • – – – Must establish login & password Auto-expiring passwords Dependent on performance of the RDBMS Dependent on performance of all network connections between the RDBMS and the user’s computer A “closed” dataset Edits generally limited to the E-911 Coordinator Can’t be accessed directly by 3 rd-party apps

Centerline Access via the Nashville. gov Web • Good for view-only access • No real analysis other than visual. • Site geared to find parcel data and other resources based on address, not specifically to query/find street data. • Google Maps or Handy. Map may be just as useful, and more user-friendly for orientation and connectivity issues, etc.

Centerline Snapshots of the “Live” CL Data • Shapefiles or personal geodatabase feature classes extracted from the enterprise CL dataset. • More suitable for use with 3 rd-party apps, but disconnected from the enterprise resource. • Edits made to snapshot may be useful for enterprise, but getting that back into the enterprise geodatabase requires careful planning and communication between departments.

Metro Nashville CL Data: Product of Multiple Sources & Processes • Some of the linework has been: – Digitized from old Mylar/paper parcel maps – Derived from plans provided by developers – Hand-digitized from orthophotography or from ROW polygons – Imported from CAD data

Metro Nashville CL Data: Product of Multiple Sources & Processes • Some of the data attribute values have been: – Bulk-loaded from other systems or projects as needed/available – Hand-edited by consultants and staff in multiple departments – Structurally re-defined as part of a recent RDBMS migration

Metro Nashville CL Data Structure & Attributes • Segmentation terminates at nodes – Intersections with other streets – Bridges – Satellite City boundaries – County boundaries

Metro Nashville CL Data Structure & Attributes • Naming – – – – PREFIX_DIR (N, S, E, W) NAME SUFFIX_TYPE (DR, AVE, BLVD, PIKE, etc. ) SUFFIX_DIR (N, S, E, W) FULL_NAME (combine previous 4 fields) ALT_NAME FORMER_NAME

Metro Nashville CL Data Structure & Attributes • Connectivity – FROM_STREET (intersecting street at segment’s lowest address point) – TO_STREET (intersecting street at segment’s highest address point) – NAVIGABLE (related to OFFICIAL_STATUS and LEGISLATION)

Metro Nashville CL Data Structure & Attributes • Addressing – LEFT_FROM (lowest address value possible on the left side of this segment) – LEFT_TO (highest address value possible on the left side of this segment) – RIGHT_FROM (lowest address value possible on the right side of this segment) – RIGHT_TO (highest address value possible on the right side of this segment)

Metro Nashville CL Data Structure & Attributes • Accepted Status – Accepted: Adopted and maintained by Metro Nashville – Davidson County – Accepted: “State Aid” segments are maintained by Metro Nashville with State funding – Not Accepted: State or Other Government / “Satellite Cities” – Not Accepted: Private Roads/Drives – Not Accepted: Under Development

Metro Nashville CL Data Structure & Attributes • Legislative Acts – Acceptance Date • Streets in new subdivisions may take years before acceptance, depending on several variables • Accepted streets in newly annexed areas would likely all have the same acceptance date. – Abandonment Date • • • Existing, but no longer maintained. No longer existing due to development Either way, it’s a historic line now. – Naming Changes

Metro Nashville CL Data Structure & Attributes • Other Fields Available – – – Many other (UNETRANS) fields available. Some are populated and maintained. Some have been partially populated for studies or short-term projects, but not maintained. – Others are there for future use, but have never been populated due to minimized need.

CL Data is the Basis for Several Processes within Public Works • Customer Service Department: Arc. View & Cityworks – CL snapshot due to connection concerns vs always-on nature of customer service. – Reps geocode incoming SR calls in real-time – Manual geocoding tools help reps to deal with SR incident addresses that don’t automatically geocode. – Cross-departmental communication ensures E 911 Coordinator knows to analyze segments w/ geocoding issues.

CL Data is the Basis for Several Processes within Public Works • Customer service reps can immediately close some service requests through simple geocoding. – When is trash-pickup day for my street? – When will my street be paved? – When will the alley behind my house be cleaned?

CL Data is the Basis for Several Processes within Public Works • Other SRs are assigned by type and priority to inspectors, who benefit from the CL data and geocoded SR data. – Immediate map-based identification of active service requests by type and status and work sector. – Inspectors benefit from visual “clustering” of active inspection workload to assist in simple route planning. – Pattern recognition & reporting over time.

CL Data is the Basis for Several Processes within Public Works • Maps and reports to enhance communication with Finance, Metro Council, other departments, and public citizens via 311 or Nashville. gov web site. • • • Paving Plan Maps Weekly Work Coordination Maps Trash & Recycling Route Maps Snow Route Maps ROW Maintenance Schedules Closure Notifications Bulk Item Pick-up Requests Dead Animal Reports Traffic Calming

CL Data Usage within the Paving Operations Office • Pavement Management workflow and maintenance decisions are supported by – Physical inspections & annual photo and distress data collection – Customer Service requests and other forms of public input – Photo log & custom Arc. GIS Roadway Viewer – Cartegraph: Pavement. View for Arc. GIS

Annual Roadway Data Collection in Support of Paving Operations • 4 photos shot every 20’ (front, frontright, rear-left, rear-down) • Laser distress analysis to help gauge roughness and raveling. • Process develops overall condition index (OCI) for use in Pavement Management system.

CL Data Usage within the Paving Operations Office • While several of these projects use CL data “snapshots”, some data elements from these projects would be of benefit to the enterprise users, so careful process management ensures that the appropriate aspects of locally-altered segment data are reflected back to the enterprise geodatabase at appropriate intervals.

CL Data Usage within the Paving Operations Office • Example: Last-paved Date • This field is updated in Pavement. View then pushed over the enterprise CL geodatabase. • From there it is imported into the enterprise Permitting system (KIVA), where it serves to trigger additional fees for applicants who apply for permits to perform pavement cuts on recently resurfaced roadways.

Collected Data Helps Calculate OCI • OCI values, threshold trigger values, and annual program funding levels influence Carte. Graph Pavement. View to make suggestions toward decisions on scheduling treatment – – – Resurfacing (mill & fill) Rejuvenation Crack seal Alternate treatment Wait

TRANSPORTEDGEID is the Key to the Use of CL Data Snapshots • TRANSPORTEDGEID is the Primary Key. However, when a segment is split (new intersection created), it results in a new TRANSPORTEDGEID value for each of the resulting “children. ” The original “parent” segment (and ID) is retired and copied to an archival layer. • This means special care must be taken to ensure that appropriate data transfer occurs in the event that segmentation changes while Paving-related GIS/IT projects are working with a snapshot of the same area.

Continued Data Improvement Through Distributed Access • As with the use of Cityworks and Route. Smart, the programs in Paving Operations sometimes uncover CL data errors (network connectivity, addressing, TO/FROM naming, accepted status, etc. ), which are then forwarded to the E-911 Coordinator for review/approval. • Such incremental improvement is another way in which the use of data snapshots — usually strongly advised against if enterprise data access is available— has proven beneficial to the enterprise as a whole.

Conclusions • Metro Nashville – Davidson County provides several means for its staff and consultants and citizens to access roadway centerline data. • Real-time street CL data is available as a geodatabase feature class served through ESRI Arc. SDE, but can be overkill for some projects and not enough for others. • Some internal projects require direct access to analyze and edit a standalone snapshot of the CL dataset. • Managed carefully, the use of snapshots can ultimately add value to the enterprise CL dataset.