Johnson unveiled a life-size, red mock-up of the New Bus for London this morning, describing it as a vehicle in progress that wold combine "a sense of nostalgia" for the much-loved Route masters with cutting-edge design and technology.
It is hoped that the first working buses will be on the capital's
streets by the end of next year or early 2012, he said.
The bus, which has yet to be formally named, is being developed for Transport for London by Wright bus of Ballymena in partnership with designer Thomas Heather wick.
Posing for photographs at the Transport Museum depot in Acton, west London, on the mock-up's rear open platform – a direct throwback to the Route master – Johnson praised the environmental advantages of the New Bus, saying it would emit 40% less carbon dioxide than a regular diesel double Decker and 15% less than the current generation of hybrid technology buses, which make up part of London's current fleet.
Fuel consumption would fall in line with emissions.
The New Bus has long been politically controversial, with critics condemning it as a vanity project and damning its £10m development costs.
During the 2008 London mayoral election campaign, Johnson was dogged by questions about the cost of the scheme and had difficulties answering them.
However, he claimed vindication this morning, insisting that the bus was a groundbreaking innovation that would set new standards for urban bus travel and bring in orders from around the world.
The old Route masters were decommissioned under his predecessor, Ken Livingstone.
Important features of the New Bus will be two internal staircases and three sets of doors, facilitating the rapid loading and unloading of passengers, which are considered a big advantage of the articulated "bendy buses" Johnson has been phasing out since his election.
Johnson confirmed that the New Bus would also have a conductor on board in addition to the driver at least some of the time.
Peter Hendy, Transport for London commissioner, said that these staff would be trained and recruited for the task rather than being, for example, police community support officers, as Johnson once suggested they might be, though Hendy stressed that their role would include "doing some of the things people expect of a person in uniform".
This is expected to include assisting passengers on and off the rear open platform and ensuring they have swiped their Oyster cards.
Hendy and Johnson explained that the rear open platform could be kept open during journeys when a second staff member was present, enabling passengers to "hop on and hop off" between stops if they wished. However, when only a driver was present the rear platform would be closed off between stops with an automatic door, operated by the driver, and at other times the driver thought appropriate, such as at night.
The interior of the bus is also "inspired" by the Route master, with the seat fabrics acknowledging those of the past.
The evolving design will now be presented to transport stakeholder groups, such as disabled people, for fine-tuning before its completion and launch.
