I don't know if it's classified as a novel. it's a story of this bloke who knows absolutely everything about the history of the Tube, secret channels, trivia, everything. there's and a bet and IIRC he has to take a photo of himself at every stop (with name of tube station behind him) to prove he can do it (maybe there's a time limit). so he starts off on this adventure and I think there might be someone else doing it too and they are racing who is fastest? aaarrgh, I can't remember!
it's about the Tube Challenge.. The main character Andy bets that he can do all Tube stations in a day, but it happens to be the day before his wedding day and he bets his passport & honeymoon tickets that he can do it. a tramp who knows the Underground really well joins him and gives him tips and offers him tactics on how to complete this insane journey.
it's such a brilliant book! I highly recommend it. thanks again for input.