Aside from having a sign that is really high off of the road next to an oil and lube place, we also found out that the Township of O'Hara is actually split into three parts, intertwined with Fox Chapel and Aspinwall. If that is not confusing enough for you, a lot of people from these towns introduce themselves as being from Fox Chapel anyway— many assuming that this is due to the high-caliber reputation of the school district. Quite frankly, I think that people do not look up for signs, and having never seen this one probably just assume that they really do live in Fox Chapel.
If working at Sears as a teenager has taught me anything, it's that people can't be bothered to read signs above eye level. If you don't believe that, I'll drive on the wrong side of the road in Chalfant.