Take a look here: the Transport of London website. Well organized, rich, usefull. Every information users needs, also with other services like RSS News about "delays", "tube enhancements", "contest and festive related informations and suggestions".
Besides, Transport system itself is powerfull, effective and "right": English people speaks about a "not enought services, so poor transport system". They are accustomed to something richer than me. And than every "Napoletane" people.
This is my first reason: I hope to dismiss my car and to use ONLY tube and other "walk-based" transports.
What about IKEA? How to transport my closet to my home? Have you ever known the meaning of "rent a car"? ;)