Does No One Clean These Windows?

I'm treating myself to a crepe with maple syrup. I don't realise that I've spilled a lot of the syrup down my front as I queue for the train, which only has two carriages today because somebody projectile vomited all over the third carriage so it had to be removed - or at least that's what I think I overhear the conductor say. We pack onto the train. A kid of about ten standing with his father and little sister is voicing his concerns about the lack of space. His mother- staying on the platform says, 'if you start to panic, just cover your eyes (she covers her eyes) and count to ten, okay?' Her eyes have the suggestion of tears in them. The boy nods, the doors close and father and children wave their mother goodbye.
'Does no one clean these windows?' asks the boy, who is almost forced to be pressed against them by space deficiency.
His father pretends not to hear, mutters something about the little girl's toilet request in thick cockney. The boy points to a plan of the train stuck to the passenger wall and the letters WC on it as if his father is the most stupid man in the world.
'Alright, alright, everyone will be getting off soon,' the father says.
'Dad, what does obstruct mean?' the boy says.