Escalators

Escalators have the capacity to move large numbers of people. They can be placed in the same physical space as a staircase. They are electrically powered, driven by chain and sprocket, and held in proper place by two tracks.

Escalators are used around the world to move pedestrian traffic in places where elevators would be impractical.The escalator system isn't nearly as good as an elevator at lifting people dozens of stories, but it is much better at moving people a short distance.

This is because of the escalator's high loading rate. Once an elevator is filled up, you have to wait for it to reach its floor and return before anybody else can get on. On an escalator, as soon as you load one person on, there's space for another.