Escalator

Escalator is the moving stairway that allows for quick, painless and efficient movement for a large number of people, while changing their levels. One cannot imagine modern life at subway stations, shopping malls, departmental stores or airports without these automatic stairs that provide a sigh of relief. 

They help keep crowds moving at pace without interruption and thus help prevent jams and crowding. Large number of people can move around a small space when it is strategically equipped with escalators.