Normative Signs: The Poetry of "Ought"

Here’s one I’ve never seen before. It’s from a covered parking garage in Ottawa.

What’s going on here? Is this sign self-contradictory? Or merely emphatic? Or is it a requirement that you first STOP, and then yield to, say, traffic coming from another direction? If it IS meant to imply something like the latter, how is anyone supposed to guess that?

(photo contributed by Julien Bissonnette)