Escalator

An escalator is a moving staircase which carries people between floors of a building or structure. It consists of a motor-driven chain of individually linked steps on a track which cycle on a pair of tracks which keep the step tread horizontal. Escalators are often used around the world in places where lifts would be impractical, or they can be used in conjunction with them. Principal areas of usage include department stores, shopping malls, airports, transit systems (railway/railroad stations), convention centers, hotels, arenas, stadiums and public buildings. Escalators have the capacity to move large numbers of people. They have no waiting interval, except during mass foot traffic. They can be used to guide people toward main exits or special exhibits and may be weatherproofed for outdoor use. A non-functional escalator can function as a normal staircase, whereas many other methods of transport become useless when they break down or lose power. While similarly designed, escalators are distinct from travelators, also known as moving walkways. The latter transports people horizontally, along the same floor, not between floors like an escalator.