In message

, at 17:24:07 on Tue, 6 Nov 2012, Recliner
remarked:
[3] by which, of course, you mean "obviously disabled". Some
people don't "look" disabled, but still find stairs difficult
or impossible.

There's also the halfway house of the many stations that have escalators
rather than lifts: not very much use to wheelchair users, but very helpful
to many other travellers who may have trouble with stairs, particularly
when carrying luggage.

Mindful that many stations with escalators (or indeed original lifts)
aren't completely step-free, typically having a short flight of steps
adjacent to the platform, and often a flight of steps to get from the
ticket concourse to the roadway outside.
--
Roland Perry