The old cliche is that you have to wait ages for a bus…but not the New Bus for London  The final validation prototype was shown to the press this morning at the Millbrook proving ground in Bedfordshire. The development and homologation process is being finished off, ahead of the first production model reaching London for a couple of months of driver training and final shakedown tweaks from October. Even though the prototype was finished in dusty bare aluminium (and compared by Mayor Johnson with “those pictures we’ve all seen of the prototype Supermarine Spitfire”) it’s clearly going to be a very striking part of the capital’s urban fabric. But more important than the styling and glassy interior is that fact that the (as yet unnamed) bus is built around an aluminium spaceframe and powered by a range-extender electric drivetrain, showing public transport can be as advanced as the best the car industry can offer. The spaceframe was exposed showing the way that the aluminium extrusions are bolted together with cast aluminium brackets. This prototype was also fitted with multiple strain gauges to test the spaceframe’s integrity as the bus is hammered over Millbrook’s pavé.The diesel generator - a 4.5-litre Cummins unit - could be seen neatly slotted in under the rear staircase and the bus’s multiple ECUs (controlling the drivetrain, air suspension and electric braking system) were also on display. The view as you descend the rear staircase is really extraordinary - the main trouble may be exiting passengers gawping at the vista. It was a remarkable thing to experience a short trip today in the Electric Routemaster. It’s just three and half years since I sent an email to Alan Ponsford, one of the world’s leading bus designers, to commission a high-tech, greener, replacement for the classic open-platform Routemaster. Indeed, the speed at which London Mayor Boris Johnson, Transport for London and Wrightbus have brought the electric Routemaster to reality is extraordinary. Moreover, the whole development – and six production buses – has cost just £7.8m. The Capoco/Autocar proposal was published in late December 2007 and welcomed by then-candidate for London Mayor Boris Johnson. The drawings got a big airing in the national press, including in The Times and on the BBC. When Johnson became Mayor in May 2008, he announced a formal competition to design a new Routemaster. In December 2008, the Capoco/Autocar technical proposal came joint first with a styling project from Aston Martin and Fosters Architects. The contract to build the bus was awarded to Wrightbus as recently as December 2009. By January next year, the first of six examples - 40 per cent more economical than a conventional diesel bus and 15 per cent more economical than a conventional hybrid - will be taking fare-paying passengers in unparalleled smoothness and silence. Seeing it sliding down Oxford Street, under the Christmas lights, will really be quite satisfying.