They’ve closed a road near where I live in order to repair a collapsed sewer-pipe. The construction workers have put up a sign saying: ROAD CLOSED.
But, since the actual road closure is not apparent until you go around a end, a lot of drivers go just to see if the road is *really* closed.
After they see that the road really is closed, they start making their way back. Their embarrassment is made worse by another sign right behind the ROAD CLOSED sign, but facing them on their return. The new sign reads:
TOLD YOU SO!