"Make no little plans. They have no magic to stir men's blood and probably will not themselves be realised." These famous words are attributed to Daniel Burnham, the ebullient American architect and planner who reshaped Chicago, extended Washington DC and championed the City Beautiful movement of the late 19th century.

On Wednesday Lord Foster announced a plan so big that even Burnham would have been impressed. The Thames Hub, a £50bn project devised by architects Foster and Partners, planners and builders Halcrow and Volterra, a consultancy group of British economists, aims to revolutionise Britain's often creaking and largely inadequate national transport and energy infrastructure.

From a proposed new Thames Hub, comprising an international airport, railway terminus, freight depot and port along with a new Thames Barrier sited all together in the Thames estuary, a new four-track high-speed orbital passenger and freight railway would run around the north of London before joining main lines to Glasgow, Edinburgh, Liverpool, Manchester, Hull, Felixstowe, Cardiff and Southampton.

Aiming to take thousand of container lorries off the roads, this radically enhanced national transport "spine" would also carry power lines and communications cables, cutting down on the need for new pylons. Built to a continental loading gauge, the railways would connect directly with high-speed passenger and freight lines in the rest of Europe.

New homes, hi-tech factories and other workplaces would be built around existing and new railway lines with tens of thousands of new homes connected directly to an ultra-modern transport network. Most new homes in Britain are currently scattered on the fringe of old towns and across the green belt with little consideration for transport and other infrastructure.

"We need to recapture the foresight and political courage of our 19th-century forebears, " said Foster on Wednesday, "if we are to establish a modern transport and energy infrastructure in Britain for this century and beyond."

The Thames Hub and the "spine" are bold plans indeed. "They're born out of necessity, enthusiasm and frustration," says Foster. "In Hong Kong, a decade ago, we were able to build a major new international airport and all the associated infrastructure including a new island reclaimed from the sea within four years. If Britain wants to compete with rapidly developing global economies, it must sort out its infrastructure and, if this is holistically planned with real political commitment it can also be a thing of beauty and environmentally friendly."

"I know it's against the national grain to come up with big plans and we'll be accused of playing Napoleon, but we have to get the debate going and show what a difference a radical new infrastructure plan could make to Britain."

"Infrastructure is the key", says David Kerr, group board director of Halcrow. "Britain ignores development and investment in infrastructure at its peril. Look around the world and you see the way in which China and Latin America are investing heavily in infrastructure. They see it as a passport to strong economic development."

Bridget Rosewell of Volterra says that, if implemented, the Thames Hub plan would generate £150bn in financial benefits alone. It has also been planned to save the green belt from rapacious commercial development, to generate hydroelectric power from the tidal Thames and to beautify transport corridors around London and along the country's main traffic arteries.

"If it went ahead, even in part," says Foster, "the very realisation of the plan would create thousands of skilled jobs in engineering, manufacturing and construction alone."

Although Britain has rarely been a country of grand plans, these have existed. The building of the railways, sewers, National Grid, motorways and water supplies are all examples of how Britain has made it in the past. Huge infrastructure projects like the city of Birmingham's water supply from the Elan Valley, completed in the early 20th century, prove how such works can be breathtakingly beautiful as well as discreet and highly effective. They can also be highly controversial, politically sensitive and hugely expensive.

"The cost of not doing anything will ultimately be much higher," says Foster, an architect used to moving mountains in the far east. "We've stuck our heads up like coconuts in a funfair expecting them to be knocked down. But we need to do something soon, and this plan is national, aiming to redress the imbalance of the economies of north and south."

Could it happen? Could we soon be flying in and out of one of the greatest ports in the world where fleets of modern aircraft, ships and trains power Britain's economy into a newly competitive age? Will we live in fine new homes connected to brand new transport, energy and communications spines and hubs? Or will we decide it's business as usual in little Britain and carry on building junk housing on what were once meadows and unsustainable supermarkets and shopping malls on the land that's left and between overcrowded roads and railways? Foster and his team have offered a big-spirited vision of Britain, but do we have eyes to see it?