An escalator is a power-driven, continuous moving stairway designed to transport passengers up and down short vertical distances. Escalators are used around the world to move pedestrian traffic in places where elevators would be impractical. For example, at discharge times from offices, railways underground stations, airport terminals, theatres, shopping malls and departmental stores. The escalator's primary attribute is its ability to move large numbers of people at once from one area to another. People can move both upward as well as downward when a pair of escalators are typically deployed next to each other. Escalators are effective when used as a means of guidance and circulation. In a complex transport situation, such as a city's subway
