Basil Jet wrote:
That's what people are implying when they say that the capacity of an
escalator is reduced by walking.

Well it all depends on (among other things) how many people walk, at
what speed, and when they arrive.

In any event given where we are starting from I'd put the proposition as
"the capacity of the escalators is reduced by the current practice of
leaving the left side empty for walkers". Whether or not that is true
depends both the number of people who walk up and on the speed at which
they do so. And also on the current incidence of people who block the
left side - eg from ignorance; by being morbidly obese; with luggage;
with large buggies; with young children.

IIRC it is a problem of a class which cannot be solved analytically but
can be modelled since computers have had sufficient grunt to process
large volumes of data.
--
Robin
reply to address is (meant to be) valid