"London orbital railway on mayor's £1.3tn wishlist." (The Brent Cross Railway is the other way at Cricklewood, and a better route for outer north London. )

Link to The Guardian

"Blueprints for a new orbital metro-style railway around London are being drawn up by the city's transport authorities as part of a massive proposed infrastructure investment to keep the capital moving as the population soars in coming decades.

"The concept for an additional fast orbital rail service linking boroughs in the inner suburbs – dubbed the R25 in City Hall – follows the rapid growth of London Overground, which has seen a boom in passenger numbers since being enhanced and integrated into the capital's transport system, helping regenerate areas and stations and decongest tube lines.

"The mayor said Crossrail 2, a new north-south line linking Wimbledon to Hackney across central London and probably extending into the suburbs, should be approved as a matter of urgency, and other Crossrail lines could follow. The transport commissioner, Sir Peter Hendy, said the arrival of HS2, the high-speed link to the Midlands and the north, into Euston station meant immediate action was needed, with a likely 15-year minimum timescale for planning and construction work."

Link to Transport page.