I had to learn the hard way about the escalator etiquette in my last job when having to take a train from and to home. To get to the station in the city you needed to go through an escalator and it was pretty crowded. I soon learned to just stop behind the line and make sure my bag or anything wasn't in the way of people that wanted to walk up and that if anyone was walking up and I had people behind I better move up too even if I am not ina hurry unless it is wide enough for me to step aside.
I understand the hurry in a train station, but I feel in general some people are pretty impatient and rude. It might seem like common sense for people using packed elevators, but some people seem to think that they are only for you to walk faster up and that standing at all is rude even if they can walk around you. Elevators are good for older people or people with disabilities and helps you so it is not as tiring. I don't really agree you are supposed to do a power walk on every escalator. If there is not people, I like standing and just let it do its thing. Some got a nice view and I really don't want to be ina hurry when no one is expecting me to where I am going.