From a post on Quora about why escalators are harder to walk up: "A stopped escalator IS indeed harder to climb than a fixed staircase of the same height. A typ

From a post on Quora about why escalators are harder to walk up: "A stopped escalator IS indeed harder to climb than a fixed staircase of the same height. A typical conventional fixed staircase has tread risers (steps) that are ~7 inches high and 11 inches deep. The escalator is likely to have tread risers that are ~8 inches high and 16 inches deep." People are more likely to fall climbing a stopped escalator than stairs due to the different stair height and depth.