Dining Hall Tray Return System

The tray return system in the campus dining hall uses a conveyor belt behind a window where you slide your tray onto the belt and watch it disappear into the kitchen. It works because it makes the correct behavior, returning your tray, easier than the incorrect behavior, leaving it on the table. I want every campus facility to think about behavior design this way, by making the right choice the path of least resistance rather than posting signs that guilt people into compliance. Positioned directly next to the exit, returning your tray requires 0 extra steps. The opening is sized to accept a standard tray but not a backpack, which prevents the system from being used as a trash chute. Noise of the belt and the visibility of other people using it create a social norm that reinforces the behavior. When everyone around you returns their tray, leaving yours feels conspicuous.