Wow. The first time I read this, I thought you were talking about differentiating forward and back slashes.

up escalator. -> _/

down escalator: \_

Do you refer to the long flat ones at airports as lateralscalators, forwardscalators, or orthangonalscalators?

I think of the way the slash would fall if it were a pen on a desk. The forward slash would fall forward / -> the back slash would fall back \ <-

Escalate already means move up, but has a clumsy opposite (de-escalate, I believe). Maybe descalator and escalator would be an alternative. However, ups- and downs- is better, plus you always get points for coining new words.