In the last few weeks we have been peppered with lots of questions about our Text-to-911 map and availability checker, so I am going to address them here.

The Text-to-911 map is really a composition of several different datasets: US County map, PSAP points, the FCC “official” availability map and our own coverage map. So why the different maps? Lets break them down:

  • US County Map – This is used as our map base. About 75% of the counties in the US only have one 911 call center (PSAP), so in determining coverage, the county map is a good place to start. Since every PSAP is in a county, it can serve as the base.
  • PSAP Points – There are over 6500 PSAP’s and over 3100 counties in the US. In many metropolitan areas, or those of high population, there are multiple PSAP’s within the county to serve different jurisdictions. We’ll talk about jurisdictions later. We have mapped out every single primary PSAP (and most of the secondary PSAP’s) for every county and jurisdiction. Text-to-911 coverage is determined by PSAP, not county. There are quite a few counties that are reflected as partially supporting Text-to-911 in the availability checkersimply because at least one of the PSAPs in the county supports it, but not all.
  • The FCC Text-to-911 Availability spreadsheet – The FCC provides a spreadsheet that is updated every 30-45 days that reflects the PSAP’s in the country that support Text-to-911. This data is wholly dependent upon the individual PSAP’s submitting a paper form to the FCC regarding coverage. This is not terribly efficient, but fortunately, we can help with that.
  • Punch Technologies Availability Map – This is our availability map that plots the covered counties/PSAP’s according to the FCC, but we take it a step further. We are proactively reaching out to all of the PSAPs in the country and asking them when they believe Text-to-911 will be supported. Believe it or not, there are many PSAPs that already support Text-to-911, but in most cases they are not aware that there is a paper form that needs to be submitted to the FCC for inclusion in the “Official” spreadsheet. In some cases we have found that the submitted form is taking 6-8 weeks to be processed. That’s why we also reflect partially supported counties.

While the FCC is the system of record for the Text-to-911 supported PSAP availability list, we feel very confident that our maps are more accurate simply because of our process to proactively determine where the service is supported.

Now lets go through the continued challenges of maintaining the maps. The coverage map is very much a living document in that the PSAP’s have to continually be consulted to determine the level of coverage. Text-to-911 sounds like a simple service, but it is far from simple. I’ll save that for a later post. I think the biggest challenge is determining and maintaining the PSAP jurisdictions when there is more than one PSAP present in a county. When there is only one PSAP, the jurisdictional boundaries are obvious and straightforward; however, with multiple PSAPs available in a county, how 911 calls are routed to a particular PSAP, is a spaghetti diagram. There is not a (publicly available) defined methodology to routing 911 calls from the wireless carriers (I know, I have asked them at various levels of leadership). In some counties, the routing is determined by zip codes (really poly lines since the zip codes are nothing more than routes), in other counties it is determined by fire response zones or various zoning laws. Regardless of how it is determined, it is anything but clear.

So, how do we use the information in our apps? We only paint availability based on total PSAP support for a county. If a county has more than one PSAP and not all of them support Text-to-911, we won’t paint that county as available. Currently, this is the safest way to present dynamic coverage. Although, we have made strides in remedying the issue. We have begun to consult the local county governments where partial Text-to-911 support exists to get emergency response jurisdictional maps. We have made headway and have begun to implement jurisdictional maps in the app coverage, but we have a ways to go since there is NO standardization for county GIS at present.

Non-standardization is impossible in this day and age you say? Ha! Now that issue will really make your blood boil, but I’ll save that for later as well