Next Generation 9-1-1 Road Centerlines Are More than Just Lines

October 31, 2022

On Tuesday, October 20 DATAMARK’s Sandy Dyre and Jeff Ledbetter will host a live webinar on NG9-1-1 Road Centerlines. To register and learn more, please follow this link:

Understanding GIS for Next Generation 9-1-1 (NG9-1-1) and the relationships between its required data layers presents new challenges to those charged with the day-to-day management of public safety GIS data, implementing GIS data within public safety applications, and preparing for NG9-1-1 deployments.

NG9-1-1 fundamentally changes the ways GIS data is used in 9-1-1 call routing and call taking. Spatial data, not tabular data, is used to perform location validation and call routing before the call is presented at the PSAP. Accurate and reliable GIS data is now at the heart of every current and future NG9-1-1 deployment, and the management of this data becomes a mission-critical function element of its success.
Developing GIS data for NG9-1-1 requires us to look at GIS differently than we did with the legacy Enhanced 9-1-1 (E9-1-1) model, especially for those migrating data from mature legacy E9-1-1 GIS environments.
The location validation function (LVF) is now performed with spatial data rather than tabular MSAG and ALI data, and this process requires the development of Road Centerline data, along with other required layers. Likewise, NG9-1-1 uses spatial data in the emergency call routing function (ECRF), requiring accurate and reliable Road Centerlines and other data layers to identify the caller’s location.

The NG9-1-1 GIS Data Model defines five GIS data layers that are critical to the successful deployment of the LVF and ECRF, chief among these is the Road Centerlines (RCL) layer. The Road Centerlines layer is integral to public safety GIS and is used for mission-critical functions across the public safety enterprise.

Road Centerlines and the NENA NG9-1-1 GIS Data Model
The NENA Standard for NG9-1-1 GIS Data Model (NENA-STA-006.1.1-2020) establishes the GIS Data Model, which is foundational to creating GIS data that supports NENA NG9-1-1 Core Services (NGCS). The Data Model defines Required, Strongly Recommended, and Recommended GIS data layers used for NG9-1-1 location validation and geospatial call routing and by PSAPs for 9-1-1 call handling and call mapping.

The Road Centerlines layer is one of five data layers required in NENA’s NG9-1-1 GIS Data Model and plays a critical role in your NG9-1-1 ESInet deployment, regardless of size or scope. Road Centerlines are an essential component of accurate NG9-1-1 GIS data; NENA identifies several critical PSAP GIS applications that rely on accurate, reliable, and consistent RCL data:

  • 9-1-1 call mapping and CAD mapping applications
  • Map display, including interactive display of map attributes
  • Geocoding civic address ranges and intelligent queries on this data
  • Creating maps used by emergency responders and municipal resources
  • Accurate location determination and navigation directions for emergency responders
  • Drive time analysis and vehicle / unit routing for emergency responders
  • Integrating spatial attributes into advanced public safety and municipal applications

While data does not need to be kept in the NG9-1-1 GIS Data Model, you will need to create and maintain your Road Centerlines and other required layers, populated with the proper attribution. Successful GIS authorities embrace and work to NENA’s standard and the NG9-1-1 GIS Data Model through:

  • Thoughtful interpretation and application of the standards and the data model within their GIS ecosystems
  • Intentional design, implementation, and management of Required, Strongly Recommended, and Recommended data layers
  • Incorporation of legacy 9-1-1 GIS fields and layers to support the transition from non-spatial E9-1-1 call routing to NG9-1-1 geospatial call routing

DATAMARK’s GIS data management solution, VEP, is designed to support the most current NENA NG9-1-1 GIS Data Model and provides the flexibility to incorporate custom fields and additional schema requirements from your existing GIS datasets. VEP is deployed with GIS authorities and PSAPs across the United States, and is used every day to create, edit, validate, and provision data for use in NG9-1-1 while maintaining seamless support for legacy 9-1-1 GIS data applications.

Does My Legacy 9-1-1 GIS Still Matter?
Prior to the implementation of a GIS-based MSAG for geospatial call routing, legacy E9-1-1 environments rely on tabular (non-spatial) MSAG and ALI databases for call routing. While it is not used for initial call routing, accurate and reliable public safety GIS plays an essential role in legacy E9-1-1 operations before, during and after the transition to NG9-1-1.

Successful transition to NG9-1-1 from legacy E9-1-1 environments requires the continued support for tabular call routing using MSAG and ALI data, right up to the point where geospatial call routing is implemented.

DATAMARK’s NG9-1-1 GIS data management solutions offer flexible configuration to simultaneously and fully support legacy E9-1-1 GIS environments at each phase of an NG9-1-1 migration. This enables GIS authorities to proactively create and manage GIS data for deployment in NG9-1-1, without impacting E9-1-1 operations, and seamlessly transition their GIS environments to NG9-1-1 with minimal or no disruption to GIS data management processes, workflows, and applications.

Next Generation 9-1-1 Relies on More than Just Lines, and We are Here to Help
Managing your Road Centerline layers for use in NG9-1-1 requires a solid understanding of the fundamentals of the NENA GIS Data Model and relationships between the RCL and boundary layers, support of legacy GIS data throughout the transition to geospatial call routing, and awareness of data issues which are commonly encountered while managing RCL layers.

As you begin to explore the opportunities, challenges, and requirements of transforming your GIS environment to support NG9-1-1 or if you are currently tasked with improving the quality and reliability of your current GIS data, consider the following questions:

  • Does my GIS data support the caller’s location completely, accurately, and precisely?
  • Does my GIS data support accurate queries for the proper routing of the 9-1-1 call?
    • Topology: Is my geographic representation correct?
    • Attribution: Have I addressed all mandatory and conditional requirements?

If you struggle to answer any of these questions, please reach out to us. DATAMARK’s team of public safety GIS professionals is ready to help, and our comprehensive suite of GIS data management solutions will equip you to meet your existing GIS needs and prepare you for the bright future NG9-1-1 offers.

By: Stephanie McCowat

Areas of Focus:

Local Governments