This is particularly true of the ’sloped’ style escalators as the incline needs to be relatively gentle or the chairs will be very difficult to push or wheel against gravity. ‘Stair’ escalators take up slightly less space, but still more than a normal stair case – if not for any other reason then because you need two sets – one going up and one going down. At the same time escalators will be more difficult to maintain and its not unusual for them to be found out of order when you visit shops or other places. Escalator maintenance will be required regularly then, and more regularly than elevator maintenance. At the same time though they are also slightly more prone to causing accidents even when all is going smoothly as people can trip, or get caught in the teeth at the top – though these accidents are all much less serious than something going wrong with an elevator which can cause a lot of destruction should it fall. They also cost more to run unfortunately as escalators need to be constantly moving at a set pace rather than just moving when they are ‘called’ like elevators.