Comment by tomatocracy
5 days ago
Not sure but I think I read a while ago that they were removed due to unreliability (it's a while since I've been there myself).
It was very clever how they did the acceleration/deceleration - the "tiles" of the walkway fit together in such a way that each could slide on top of the next one, and at the two ends the tiles would gradually slide closer together (decelerating) or further apart (accelerating).
They were still there pretty recently when I was there. All escalators are a pain for maintenance though. Sure it's cheaper to force people to walk but that's not the point.