I was reading on the archive pages that a member of the forum was planning to construct the whole London transport network on the London Map...
After 3 months I have done it! Full Underground, Mainline and Suburban Railway (incl. London Overground), Tramways, DLR (using monorail), and Thames Riverboat Services; I have also built the major motorways, 'A' roads, airports, and Thames bridges/tunnels. All the routes have been tested and have one unit working on them at present.
I am currently working through the 800+ bus routes which I am having to shorten in some cases to avoid congestion in the City, Westminster, Camden, and Lambeth areas. The Underground in some areas has been built on elevated lines due to the heightfields relation to the river, but I can probably raise land and amend them with time.