[efes]

I think the article is missing the obvious point that the queue at the bottom affects walkers as well as standers even though it is being formed by the delays caused by standers needing more time on the escalator. Allow walkers up the middle well separated escalator without interference and many more people would walk.

[Swannie]

I doubt it. Even if you are relatively fit, many of these escalators are equivalent to 2 - 3 flights of stairs, after sitting standing in a hot carriage for 30mins plus.

The speed that you are expected to ascend as a "walker" is high. I know, because I used to climb every day, and I would get disapproving noises/looks if I failed to climb with sufficient speed.