I was waiting for a bus a fortnight ago in Cesky Krumlov. There was quite a crowd of people at the bus stop, but none of them were queuing. That includes me - a Brit! We all milled around chatting, I and a number of others sat on a bench. The bus appeared and still no queue materialised, instead everyone moved towards the bus door and formed a disordered huddle. It was a very polite huddle, but a huddle nonetheless. The only friction arose when some schoolchildren pushed in front of an elderly lady, but they soon were put in their place by a stern word.
Then a few days ago I waited for a bus in Cheltenham. Of course there was a queue. There would have been a queue, regardless of how many people were waiting. In fact the Brits will form a queue of one - I do. There's an empty bus stop, what do I do? I stand next to the sign looking in the direction of the bus. Arrivals at the bus stop then form a queue behind me. If anyone pushes into the queue they are subjected to stares and even the muttered comment "Some people have no manners, really!" But they are unlikely to be challenged.
Such queuing behaviour is relatively easily to read for non-Brits, what is more difficult is the virtual queue. What do I mean by that? Well, a good example is in a pub. In my youth I worked as a barmaid and so had an opportunity to observe it closely. You do not form a queue when you want to buy a beer, but there is a virtual queue. The barman serves people in the order in which they arrived at the bar. To register your presence with the barman you catch his eye, often with a jerk of the head backwards. He will nod to acknowledge you and then you wait your turn. This can be problematic in a very crowded bar, but as a barmaid I soon learned that the skill of remembering the order of the virtual queue is essential.
Once a snooty customer said to me ""When are you going to serve me, I'm an undergraduate of Oxford University?" There was a stunned silence in the bar, fellow students tried to hide and the locals clenched their teeth. Every rule of English behaviour had been broken.
In such a circumstance the barmaid is entitled to lose her British reserve. "And I'm a graduate," I replied, "And you'll bloody well wait your turn." General cheers.
I've heard the argument that the British queuing habit is due to rationing. But I think that is complete tosh. Rationing was over 50 years ago and still we are doing it. Plus I rather suspect that under the Nazis and then under the Communists the Czech too would have been used to queuing, indeed Czech bureaucracy still requires it. They just don't do it all the time.