A blank facial expression (Somewhat similar to a poker face) used while riding a bus. A person sustaining a bus look is often in deep thought or examining the surrounding people. Off the bus, this can be considered acting Stoic.
"I stepped on the bus and looked down the aisle, all I saw were a bunch of people with bus looks minding their own business."
"I was too absorbed in my bus look and didn't realize you wanted to talk to me."