Not a joke. It's at a T-junction, where Campbell Street runs into Little Queen Street
which is one way to the left on the left and one way to the right on the right. Which
means the sign is unnecessary: it doesn't restrict you until you have turned, and then
only if you try to come back, which is impossible as the street is too narrow to turn
in, and you can't see the sign then anyway. So how else could you express it?