Up in up in Ontario, Canada our temporary signals are less of a spaghetti factory than these But Interesting, streetsign is the same green/white, size and outline as ones in my city!
The signals are not temporary, they're permanently installed. And yes, they're haging by tension wires, and they're like that in my area, but not all of it, some of the signals are held by a thick metal arm.
Hmm I don't see whyb they would have attached to the street light pole. A properly designed spanwire set-up should only need the four large posts at the most. A basic installation could get away with two posts and the spanwire going across the intersection at a 45 degree angle.