Etrex Venture HC: Highway Page...mostly useless?

 

I looked around a bit, and it didn't seem like this question has been asked before...

I just got my first GPSr, an Etrex Venture HC. It has a screen called "Highway" that seems to be pretty much useless unless you're navigating (a route or just to another point). It doesn't show any map data, at least not from the basemap or the map I made from OSM data.
Does anyone know of a resource that might explain how to get map data into this screen, should it even be possible?
Thanks

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Venture HC