Aside from at the ticket office (and alongside platform edge doors like poster above has stated), where is there to queue at a railway station?
Lifts and escalators, Lifts - people do queue but tend to let those in a wheelchair or with a pram or pushchair on first in my experience. Escalators - a natural queue except for individuals who want to walk fast who may take the left hand lane (and get irritated with those ahead of them who are moving more slowly).
Getting on the train there is often no natural place to queue from (apologies to drivers), so passengers find a gap along the platform edge or, if it is off peak at my nearest station, just stand around - there will be more doors than passengers. No queue - one behind another - because it is a narrow platform and a queue more than two deep blocks it. They will also tend to move to that part of the platform which will enable them to get out of the destination station quickest, irrespective of when they arrived, if you don't know - head for the middle.
It depends on the station, next nearest has an incredibly wide platform (island - only one side in regular use). You can stand anywhere to wait, even in peak (or first off-peak), you will get a seat (near the start of the route).
@birchesgreen quotes New St, I'm in South Eastern. Morning peaks - almost no-one getting off, quite a few getting on; day - some getting on and off; evening peak - quite a few getting off, occasional getting on. New St is different, the worst of all worlds, times when there will be lots on and off. Not exactly the same but I can remember trying to get on a peak train at Coventry with a broken arm - the staff took pity on me and let me sit on a drop down seat by a door - it may have been in first class. Thanks again, if the staff member is reading!