Categories: GIS Industry

The Critical Role of GIS in NG9-1-1

Drew Fioranelli, GISP, Public Safety GIS Market Maker, and Annie Cahill, Public Safety GIS Technical Manager with DATAMARK, discuss the history of 9-1-1 infrastructure as well as the foundational role of GIS and GIS professionals in the transition to Next Generation 9-1-1 (NG9-1-1) .


The 9-1-1 system –life-critical to all citizens – has remained essentially the same over the last 50 years. Over the last decade, public safety and geographic information systems (GIS) professionals have heard about an overhaul to the 9-1-1 infrastructure. The overhaul not only includes hardware and software, but a complete change in the call-routing process which relies solely on geospatial data. In most 9-1-1 systems today, GIS has a passive or referential role in public safety and computer-aided dispatch (CAD) systems. In the Next Generation 9-1-1 (NG9-1-1) environment, GIS will not only have an active role but will be a mission-critical component of the system. With the role of GIS changing within public safety, many localities at the state and local levels are evaluating the level of effort required to prepare their GIS data for NG9-1-1. Most localities with transition efforts underway agree that preparing GIS data is the most challenging and time-consuming part of the process. As the role of GIS changes for public safety, inevitably the role of the GIS professional is evolving.

When 9-1-1 was developed 50 years ago, geospatial technology was is in its infancy and its originating purpose was to support land management, not to save lives. Several decades later, the value of GIS has changed the landscape of many business practices, and public safety is no exception. NG9-1-1 pushes GIS beyond supporting CAD mapping interfaces to become a core component required for emergency call routing and location validation. This also means a shift in responsibility for local data authorities, as NG9-1-1 will not rely on the master street address guide (MSAG) and automatic location information (ALI) databases, which are owned and often maintained by telephone companies.

Shifting responsibility for data to the locality means the roles for those managing GIS data will also change. GIS professionals are in a way becoming “geospatial first responders” due to the critical nature of GIS in NG9-1-1. The NG9-1-1 environment requires GIS data with the highest level of completeness and accuracy possible, maintained in highly granular schemas. The National Emergency Numbers Association (NENA) developed the NG9-1-1 Data Model (NENA-STA-006.1-2018) to provide GIS practitioners a model standard to support NG9-1-1. The model specifies the GIS data layers required, a detailed schema for each layer, and spatial reference information. Transitioning to this new data model will require thoughtful interpretation and consideration, and a greater understanding of database design and management.

The NG9-1-1 environment requires GIS data with the highest level of completeness and accuracy possible. DATAMARK VEP’s Validation Rules flags address anomalies. Map from: Uncovering Hidden NG9-1-1 GIS Data Problems with DATAMARK VEP

GIS Data Standards for NG9-1-1

The GIS data required for NG9-1-1 may already exist in an organization, or it may need to be created. Existing data may include road centerlines or address points, while other layers may require creation, such as emergency service boundaries (ESBs), public safety answering point (PSAP) boundaries, and provisioning boundaries. With each of these required data layers, NENA identified specific standards the data must meet before it can be used to support NG9-1-1.

Road Centerlines:

  • Edge-matched
  • Split at PSAP Boundary
  • No gaps, overlaps or duplicate centerlines

Address Points:

  • Most precise resource
  • Structure-based, sub-addresses as available
  • Includes non-addressed dispatchable locations

PSAP Boundary:

  • Created for the Primary PSAPs only
  • No gaps, overlaps or duplicate polygons

Emergency Service Boundary (ESB):


  • Fire, police, EMS response areas (created as separate layers)
  • Not the ESZ or ESN Layer
  • No gaps, overlaps or duplicates

Provisioning Boundary:

  • Provisioning authority has rights to provision GIS data to the Spatial Interface (identified as the SI in the NG9-1-1 i3 infrastructure

When all GIS data is present and meets the specifications in the model, it must be validated and synchronized with the existing MSAG and ALI tabular data currently used to support legacy 9-1-1. The GIS data is validated among features within each layer and validated layer-to-layer. Spatial validations are critical to the integrity and accuracy of the data and should be performed on a regular basis to accommodate the dynamic nature of GIS. GIS professionals should explore validation options and establish a quality control routine, as well as document any processes related to NG9-1-1 GIS layers in the standard operating procedures (SOPs).

GIS and Integrating NG9-1-1

In many localities, GIS is enterprise-level and integrated into many systems within the organization, but in some localities, GIS still exists in a silo. To be successful, NG9-1-1 requires efficient communication and collaboration among all stakeholders, especially important for data creation. GIS professionals may need to engage PSAP managers when creating Emergency Service Boundaries (ESB) or PSAP boundaries, as public safety professionals have first-hand knowledge of response area geography. If the address manager for a locality is not a GIS professional, communication is even more important to ensure addresses are assigned and managed with NG9-1-1 best practices in mind.

GIS professionals must be prepared for the shift in responsibilities and equip themselves with the knowledge and tools required of a geospatial first responder. It is never too early to prepare GIS data, since it will involve a high level of effort for many GIS professionals. Start today assessing GIS data for completeness and accuracy and become familiar with the NENA GIS data model. Research validation tools and evaluate the resources required to correct any anomalies. Most importantly, communicate with other stakeholders to ensure efficient workflows in the NG9-1-1 environment. NG9-1-1 is changing the way we do business and the way we save lives, and the role of the GIS professional is expanding to reflect the critical nature of GIS. It may seem overwhelming but starting early with data validation and engaging frequently with stakeholders are small steps GIS professionals can take today that will have a big impact on NG9-1-1 in the future.


About the Authors

Drew Fioranelli
Drew Fioranelli, GISP, is a Public Safety GIS Support Specialist at DATAMARK. He has many years of experience with public safety GIS workflows and the full suite of Esri products and enterprise and relational database management systems. Fioranelli has experience working with the States of Virginia and Mississippi on NG9-1-1 and GIS-related projects, as well as collaborating with technical team members on technical briefings, analyses, and other outreach. He supports the day-to-day technical problem solving for DATAMARK’s NG9-1-1 GIS projects. As the GIS Specialist for the State of Mississippi and Virginia, Mr. Fioranelli helps with GIS support and analysis as well as other technical support as needed.

Annie Cahill
Annie Cahill, GISP, is a Project Technical Manager at DATAMARK. Cahill has many years of experience with public safety GIS workflows, the full suite of Esri products and enterprise and relational database management systems. She also has experience working with the States of Virginia, Maryland, Indiana, and Florida managing NG9-1-1 and GIS-related projects, as well as collaborating with technical team members on analyses, standards development and best practices, and other outreach. She manages the day-to-day technical problem solving and provides oversight for DATAMARK’s NG9-1-1 GIS projects. As a GIS Project Technical Manager, Annie helps with GIS support and analysis as well as NG9-1-1 education and other technical support as needed.

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