I just looked through hundreds of photos of traffic lights on google, and not one was of the standard yellow US kind that hangs from a wire.

Inference: your neighborhood (or your belief about it) is not representative and yellow and/or hanging from a wire is not standard. I was surprised by the diversity of results on google. On the first page, there were no yellow-on-a-pole and just two cantilevered yellow ones. Bing put a cantilevered one first and had a couple on wires[dead] in the top 20. But they weren't yellow! They do seem to be in the US. Maybe traffic lights aren't yellow?

ETA: Bing's "similar images" produced a few yellow lights on wires, but it was still dominated by the familiar green and gray.