After my post on television broadcast areas as a proxy for population density, I thought I’d have a look at cellular service area boundaries. Here, lighter areas represent more (or, really, redundant) cell coverage. This data is also courtesy of the FCC.
I expected this map to more or less mirror the television map, with added coverage along highways. It does this to a degree, but there are some unexpected patterns too. Dallas befuddles me, for example (though this is probably an odd data issue, rather than an actual lack of cell reception in the 9th largest city in the US). Something that does seem interesting to me here is the clear state and county boundaries that appear. Notice how easy it is to see the Maryland-Delaware line, as well as Minnesota-Iowa and others. So, what’s going on? Is this a tax thing? Is there some benefit to building cell towers on state lines? Or is this simply a matter of small overlaps where cell towers are built to “just reach” state lines?
I don’t rightly know. But I’ll post it up, if I find out.

