MCP Insights

Whitepaper Cautions Against Using TIGER Data for GIS Data Development

Posted on May 21, 2020 by Glenn Bischoff

Geographic information system (GIS) data is a foundational component in the migration to, and continuing operation of, Next Generation 911 (NG911) systems.

But developing local GIS data so that it aligns with NG911 standards is a laborious and time-consuming process that can take months or years to complete.

Despite this, MCP’s Robert Horne, one of the firm’s GIS gurus, cautions in a recent whitepaper against taking shortcuts in developing GIS data for use in a NG911 environment. Specifically, Robert writes that public safety agencies should avoid using the U.S. Census Bureau’s open-source Topologically Integrated Geographic Encoding and Referencing (TIGER) data for 911 call-routing purposes. TIGER data is available free of charge, but does not meet basic public safety requirements, nor the established NG911 standards, Robert writes. This is due to incomplete data attribution, poor spatial accuracy, incomplete coverage of the PSAP’s jurisdictional footprint, inaccurate street names and address ranges, and a lagging data update schedule.local GIS data so that it aligns with NG911 standards is a laborious and time-consuming process that can take months or years to complete.Apparently, the adage, “you get what you pay for” applies to TIGER data.

Some of the specific problems that have plagued the TIGER data files include:

  • Poor positional accuracy—up to three miles for jurisdictional boundaries
  • Gaps and overlaps in line segments
  • Duplicate and missing features
  • Missing attribution

Robert further writes that it is imperative that the GIS data used to route emergency calls in a NG911 environment be spatially and topologically accurate and fully attributed to a standard database schema. He adds that the highest-quality GIS data is sourced directly from the local jurisdiction.

Here’s a short excerpt from the whitepaper:: GIS Data for NG911

Deploying substandard GIS data into the NG911 ecosystem contradicts the goals of NG911 by introducing undocumented errors into the location databases, or omitting locations from them. This potentially causes a 911 call to route incorrectly, thus significantly increasing response time to the population that NG911 is designed to assist.

The reality of time, effort, and cost can be overwhelming and may lead a 911 entity to seek a quick fix. However, sacrificing long-term viability for short-term gains creates a situation that is contrary to the reasons for investing in NG911. Moreover, a quick-fix solution can cause the community to lose confidence in the 911 system, because performance is no better, or even worse than, the legacy solution, and would require additional cost to implement corrective solutions.

The whitepaper contains much more intelligence on this topic—click here to download a copy. And, if you're interested in learning more about how to execute a GIS plan, register for our upcoming webinar at 11 a.m. EST on Thursday, May 28. 

MCP’s GIS team has extensive experience and expertise in guiding public safety entities in their development of GIS-generated geospatial data that is appropriate for use in a NG911 environment—please reach out.

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