The open-platform bus that allows passengers to hop on and off without waiting for the driver to release the doors could return to London’s streets, only this time it would be able to carry wheelchairs and prams.

The “son of Routemaster”, as the new design has been dubbed, strongly resembles the original, which is still one of the capital’s best-recognised symbols, despite being withdrawn in December 2005.

Capoco, one of the world’s leading bus design companies, which helped to develop the majority of London’s 8,000 buses, has produced detailed plans for a Routemaster replacement that could enter service within three years.

It would burn hydrogen rather than diesel, meaning the only emission would be water vapour.

The design has been welcomed by Boris Johnson, the Tory candidate for the London mayoralty, who has promised to phase out the bendy buses that replaced Routemasters on key routes.

He said: “This design could give us a beautiful successor to the Routemaster, with the freedom of being open to the street. We can think for ourselves and don’t need to be told when it is safe to get on and off.

“Bendy buses are miserable, inhuman and socialistic and should all be pensioned off to a Scandinavian airport.”

Ken Livingstone, the Mayor of London, promised in 2000 to save the Routemaster, which he said “only a ghastly, dehumanised moron would want to get rid of”. But he reversed his position four years later, saying that they were inaccessible to wheelchairs and larger prams.

The new bus would have four more seats than a Routemaster and standing room for 30 people, twice as many as its predecessor.

A hydrogen-powered generator would charge batteries, which in turn would drive electric motors on each rear wheel.

The absence of any mechanical link between the engine at the front and the wheels at the rear means the floor would be much lower than on a Routemaster and there would be no awkward step up from the platform to the lower deck. A set of double doors at the front, equipped with a sliding ramp, would allow level access from the pavement.

It would be made largely of aluminium, and three tonnes lighter than a modern, steel-framed doubledecker. It would cost about £150,000, a third more than a modern bus, but the gap would narrow over time with economies of scale.

Transport for London (TfL) said that the design was still likely to be too expensive because it would have to reintroduce conductors to monitor the open platforms.

But Alan Ponsford, Capoco’s founding director, who was commissioned to produce the design by Autocarmagazine, said that cameras could do the conductor’s job.

Travis Elborough, author of The Bus We Loved – London’s Affair with the Routemaster, said: “People feel trapped on modern buses, on which they are ferried to destinations chosen by someone else rather than being able to hop off in a jam.

“The open platform mirrored the liberty of London. Standing there with the wind in your hair, you felt that the city belonged to you.”

A TfL spokeswoman said that it had no plans to introduce any more bendy buses, but nor was it planning a new version of the Routemaster.

She said that the open platform had contributed to several deaths or serious injuries a year.

She admitted that bendy buses had doubled the pedestrian injury rate and almost tripled the cyclist injury rate of the average London bus. But she said that bendy buses only operated on the busiest routes and, when compared with modern double deckers on similar routes, they had a better safety record.

A 21-year-old man died in October when he fell under a bendy bus in Ilford, East London, and was dragged for more than a mile.

History of the Routemaster

1954 Prototype launched

1956 Entered service. It was designed to replace the trolleybus

1982 Replacement with modern-doubledeckers began

2005 Last Routemaster withdrawn from general service on December 9

2010 New RMXL?

— Sixteen Routemasters are still in service on two heritage routes in Central London – from the Albert Hall to Aldwych and from Trafalgar Square to the Tower of London

— About 2,800 London Routemasters were built. Less than half survive

Sources: Capoco, Autocar, Routemaster Association, Times archives

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