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.

About £200bn of spending on transport infrastructure alone will be needed in the capital by 2050 to keep it in the top tier of world cities, according to the London mayor, Boris Johnson. Predicting that London's geography would shift to the east as the population passes 11 million, Johnson said unfashionable Barking would be the Piccadilly Circus of a century's time.

Johnson was in the east London borough to launch his London Infrastructure 2050 plan, which he described as "a real wake-up call to the stark needs that face London over the next half century".

He said: "Without a long-term plan for investment and the political will to implement it, this city will falter. Londoners need to know they will get the homes, water, energy, schools, transport, digital connectivity and better quality of life that they expect."

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.

"If HS2 gets there before Crossrail 2, there will an awful lot of people walking around [Euston] because they won't be able to get on the tube," Hendy said.

The mayor reiterated his wish to build a series of new river crossings and an inner orbital road tunnel. Planners hope to deal with the increasing demand for road space by encouraging freight vehicles underground.

zone three orbital

Johnson toured a brownfield development in Barking on Wednesday where housebuilding has stalled due to lack of transport links. Barking Riverside, a swath of former industrial land sandwiched between the A13 and the Thames, has been earmarked for almost 11,000 new homes but planning permission has been granted for only a fraction of that until rapid transit arrives – leaving some who moved in to the development a decade ago dependent on cars to reach public amenities, with the first bus services starting just two years ago.

The Barking and Dagenham council leader, Darren Rodwell, said: "We're happy that this development is happening but it's got to happen in the right way." He said he was acutely conscious of issues from rebuilding other boroughs, such as Tower Hamlets, now home to Canary Wharf. "You've got the mega-rich and the mega-vulnerable and this great divide."

But Johnson said: "This will be Piccadilly Circus here in 100 years' time." The mayor, whose ambitions still include a new four-runway hub airport a little further down the Thames estuary, said: "Transport infrastructure makes all the difference to the prospects of a community." If the proposed Barking Riverside station is built, he said, "you can have new developments down that rather beautiful-looking riparian vista."

Johnson in fact cancelled an extension of the Docklands Light Railway to the borough early in his mayoralty, as well as plans for a nearby Thames crossing. He defended that decision, saying the slower and more expensive DLR would not have delivered the same impact.

The infrastructure plan also pointed to increasing pressure on energy supplies, water, schools and housing, with about 50,000 new homes a year needed to meet demand. Johnson said: "Population growth is unstoppable. You've got to go with the grain of how people want to live their lives. If they want to live in the greatest city in the world, there's no point in trying to fight them off with a pitchfork."

However, the mayor ruled out building on London's green belt. Noting that the name Barking derived from the birch, Johnson said development would include green space and trees. "We will bring back the birch to Barking," he said.

The full wishlist has been costed by the consultants Arup at nearly £1.3tn. Johnson said it was not "zero-sum" and that spending on the capital would generate growth, adding that other cities supported his call for greater local tax-raising powers to fund development.

"What is good for London is good for them, in the sense that there will be a massive tax export from this city to the rest of the UK. This is not London wanting a bigger slice of the pie, it's increasing the size of the pie."