Schools: How to be alerted to school zones on automotive Garmin GPS devices that don't have Garmin-provided school zone alerts

CraigW's picture

Many Garmin automotive GPS devices now offer school zone alerts. These alerts are amazing in that they alert in various ways depending on day-of-week and time-of-day. My experiences with a nuvi 3597, a 2014 Garmin device, to date show that Garmin's factory-installed school zone alerts behave in this way: driving through one on a school day during school hours gives a visual and audio alert and the nuvi speed limit is lowered to the school zone speed limit; driving through one on a school day before or after school hours results in the same alerts but without the speed limit change; and on weekends, no alert occurs at all.

Prior to these Garmin-provided school alerts on the new nuvi models, there was--and still is--a way to use POI Loader and Custom POIs to create a "school zone" set of files that offer alerts. This Custom POI includes a school icon appearing on the map as well as audio which in my choice of files, says "Attention, school ahead." If your automotive Garmin GPS device does not offer School Zone alerts, this is the procedure that can be used to add alerts. Unlike the new Garmin School Zone alerts, the Custom POI alerts described here do not change your device's speed limit and the alerts occur 24/7/365.

What follows is what I use for an all-USA "school zone" poi. If creating your own local School Zone file where you use actual School Zones rather than Schools (buildings) for POI locations, my procedure will not be needed. But if you're using a POI file that uses locations of the school buildings and you want to use it for School Zones alerts, you will likely need to follow my procedure.

First, download the Schools POI file from The Factory with its 170,258 schools:

Unzip the file and use the csv as you would any other Custom POI.

Rename the file to include TourGuide; e.g.:


Download an icon and audio file from The Factory and rename each, e.g.: Schools_TourGuide.bmp, and Schools_TourGuide.wav (or if your older nuvi can play mp3 audio, Schools_TourGuide.mp3). For TourGuides to work, an associated audio files is required--it is not an optional feature. All recent Garmin devices can not play mp3 audio, so the use of wav files is a better choice since all Garmin automotive GPS devices can play wav, even those that also can handle mp3.

To use wav audio files, PC users must also have sox.exe installed to their PC:

Load to your GPS with POI Loader in manual mode and set an alert distance for the Schools_TourGuide file. I use 550 feet. I find that if I use a larger value, I get false positive alerts for schools on adjacent streets parallel to me. You can tinker with this setting but for me 550-600' is what works best for me. If you live in a rural area with small towns rather than large cities, a larger radius should be tried. Some in rural areas use a quarter mile.

Make sure that alerts are turned on with your GPS, then either take your GPS out for a drive or run a simulation past some schools and see if you get alerts. If you at first do not receive an alert, don't give up. Post your results to any of the Garmin threads regarding School Zones and the users here will work with you to figure out why your device does not have the expected alert.

For beginners, I do NOT recommend starting with this Custom POI installation. I assume folks trying this are already familiar with Garmin's POI Loader program used in manual mode, familiar with installing bmp icons and audio (remembering that wav files and sox.exe are required for most new nuvis, while mp3 can be used on several older nuvis), and understand the special nature of TourGuide compared to other POI files. For those needing help, a search through The Factory's FAQs and message archive is where you need to start.

Why TourGuides? With this schools POI file, the locations identified are the actual school buildings which are oftentimes set back quite a ways from the roadways, meaning that driving past the school will not result in a GPS alert if the POI location is approximately 100 feet (30 meters) or more from the centerline of the roadway. As an approximation of School Zone locations, using the Schools file as a TourGuide with a 550' distance will set a radius large enough to include the streets adjacent to the school and will offer an alert. I find in general that I get an alert about 50-100 feet before I see most schools' 15mph School Zone warning signs. A larger warning distance would be desirable but that would increase the number of false positive alerts (schools on adjacent parallel streets, for example). If you primarily drive on rural roads, experiment with using alert distances larger than my suggested 550 feet designed for use on city streets.

Notes on the Schools POI file: 1) the file is USA-only; 2) the file is a zip and needs to be unzipped; 3) the description states that changes are made to this file 1-2 times a year although I suspect it's much less frequent that that; 4) The Schools POI file does not appear on your "My Favorite Files" list at The Factory so you need to check it on occasion for updates; and 5) there's no indication of revision dates so you almost need to download the file every now and then and see if the file size is different than the one you're currently using. If different, it's time to install the newer version--if not, then you can keep using the older one already installed to your GPS.

More discussion:

See also

Change History

  • CraigW - Aug 28, 2014
    Improved "along the route" description and information thanks to jgermann

  • CraigW - Aug 28, 2014
    Added link to charlesd45's faq on wav file audio alerts

  • CraigW - Apr 15, 2014
    Revised title to potentially aid searches