[QUOTE=slaphead]
Straight escalators are easier to engineer and when not running turn into plain, if slightly awkward, stairs. Given the well-known “can’t walk down a stationary escalatory” syndrome, I imagine a stationary spiral escalator might be a bit of a challenge, especially after chucking-out time.
[/QUOTE]
Ah, OK. But yes, the impression I’ve gotten from the links so far is these escalators have a far greater radius than those stairs, and so I suspect there’s little extra difficulty walking down them compared to straight ones. Of course, that also removes any of the benefits of a smaller volume needing to be excavated.