p's and queues

So here's something that happens most mornings...

I get to the National Rail station, from where a train to central London leaves approximately every 15 minutes. I go to the counter to buy an off-peak travelcard (after 9:30 the price goes down by half and I take the 9:31 train). The teller informs me that the train that was supposed to come at 9:15 is late. I check the clock; it's about 9:25, which would ordinarily give me enough time to buy a ticket and get to the platform HOWEVER, since the 9:15 train still hasn't come, the teller can't sell me an off-peak train ticket, for fear that I might jump on the 9:15 train when it comes at like 9:25, thereby bilking London Transport out of six quid.

So all of us waiting for the 9:31 train and the coinciding cheaper fare, have to queue so that when the 9:15 train finally pulls in and out of the station at about 9:28 or so, we can all rush to the counter to get our off-peak tickets before the next train comes at 9:31.

Ah, efficiency.