You may find more info regarding how to step onto a moving escalator in articles on the net regarding Visual Processing Disorder or visual processing problems.
It's a very complex motor skill for anyone let alone someone with Dyspraxia and also for people with other conditions that might affect their vestibular system. Combine that with all the excess sensory stimulation in areas where escalators are usually positioned, it can be impossible.
I know from memory that Temple Grandin has talked about this problem with escalators in Autism spectrum articles as well.
I know a good technique for walking across uneven or shiny tiled shopping centre floors but haven't a clue how to get down an escalator. Let me know if you figure it out please.
take care there.