There's no way to detect that via signals because if there's no cell reception, people's phones won't report back where they are/aren't driving. So you'd have t

There's no way to detect that via signals because if there's no cell reception, people's phones won't report back where they are/aren't driving. So you'd have to report it by hand if you care. Anyway, if it's showing on a consumer map that probably means it was never removed from official data sources like USGS TIGER.