Major roads have a “welcome to wherever” sign but minor ones won’t. They’re always a clear delineation in the pavement, though, because neither state is going to pave one single molecule of distance further than they have to. And they never seem to be able to arrange it so that there isn’t a noticeable bump at the junction.

One of my neighboring states also has some kind of pathological aversion to putting complete and legible signs for the names of roads at intersections, too. So the disappearance of all useful street signs is therefore usually also a clue.