Nope, the circle lines is most definitely underground, they've got buskers and everything.
I'll concede the met line though, but it SHOULD be underground, along the holes of towns it goes through, like Chesham.
District? That's the green one nobody uses, yeah?
Trains are rubbish on slopes, it's a fact.
That's why we DON'T have the Hillary Tensing Scenic Railway up Everest. That's why the one going up Snowdon takes the roundabout, more gradual route through Liverpool and some parts of Manchester.
That's why the hero always has to decouple the carriage with the bomb when they're on the hill, so it rolls away.
Come on, trains and hills mix about as well as Fred West and Patios.
Erm I dunno... is it generally lower rent in Acton? Better public toilets? Less of those unsightly pigeon nail things on any flat surface... Ok, I give, what is the difference between Piccadilly and Acton?
The wheels are ridiculously slippery. That's why 2inches of snow can bring the whole network to a halt.
That's why the wrong sort of wet leaves can bring everything to a stand still.
That's why trains used to carry small amounts of sand in compartments just in-front of the wheels... the driver could pull a lever to drop some sand on the track to get more traction... something modern trains don't have.