There aren't any signs. It's just common and accepted etiquette that an escalator serves two purposes:
Moving while relaxing.
Moving while moving.
You stand on the right and walk on the left. Walking is also safer because you do not run the risk of jamming your toes in the mechanism for lack of paying attention.
Moving while relaxing.
Moving while moving.
You stand on the right and walk on the left. Walking is also safer because you do not run the risk of jamming your toes in the mechanism for lack of paying attention.
Art by Berrod!