I am sorry the explanation is coming after, network here is not really stable.

An escalator moves in stages, I don't know which word can perfectly describe that but it comes out in slides. This reminds me of a game I played with whot cards when I was much younger. Story for another day, lol. This slides describes clue 4.

Escalator is a 9 letter word, describing clue 1.

It can go up and can go down. At the mall there are 2 at every position, one that goes up and another that goes down and it doesn't go around but in the direction it is set to. This describe clue 2 and 3.