Jump to the content zone at the center

Why do the doors of elevators work and close very slowly in the metro systems?

(1)All the elevators at metro stations have a short vertical travel distance between stops and a small number of stops (between 2 and 3 levels). Based on considerations of acceleration in hydraulic elevator systems, the Department of Rapid Transport Systems,Taipei City Government designed the elevators on principle of "a speed limit of 30m per minute for vertical travel of less than 8m and a limit of 45m per minute for vertical travel of more than 8m" to provide passengers a comfortable and smooth service.
(2)Elevators were equipped with photo-electric sensors and door closing times were extended to ensure the safety of the elderly, disabled, passengers with children or with encumbering baggage, who are the primary users of the elevators and who share the characteristic of moving slowly.