For this application, a rock on a string suspended from the ceiling above an encircled “X” would suffice.
And you could have a red-line circle noting ‘time to go’.
Just like this one, only different.
“Just like this one, only different.”
Let me guess that sign’s location: Between Rawlins and Casper right?
I had a mountain bike in a roof carrier on a road trip. The bike was vertical when i left Casper and almost horizontal when i stopped for gas in Rawlins.