I would hate to have to navigate London in a wheelchair. Only a few of the Tube stations are accessible (in terms of having the accessible symbol on the map to say they've made an attempt - I don't know what proportion of those are actually accessible), and buses aren't exactly going to be much better.

Do you really have to book the ramps 48 hours in advance? That's terrible. I'd assumed you could just roll up and ask one of the staff.

I did hear a horror story from one girl who was stuck on the train and missed her stop because the staff at the station she should have been getting off at forgot to bring the ramp. On a long-distance train with stops half an hour apart, and hourly trains going back the other way, that's no joke.