Escalator anxiety is not so much of a problem because if I fear I get tripped over by some criminal then Obsessive Compulsive Disorder (OCD) would kick in and the ability to handle disaster situations would make me slide or run on the escalator!

So its balance; and determining which step to step onto. The latter comes from shaky legs. I may worry on the lead up to the escalator on how I will approach it. As you said empty and crowded escalators are a bit frightening.