Normative Signs: The Poetry of "Ought"

Here’s a sign at Philadelphia International Airport, which seems to suggest that the world is a very scary place. All sorts of things are apparently seriously dangerous, including wheelchairs, walkers, and (gasp!) open-toed footwear.

Of course, the dangers become more plausible once you see that the sign is located next to (but doesn’t actually refer to) a moving sidewalk.

Thanks to Wayne Norman for yet another pic.