The AEC Routemaster is a front-engined double-decker bus that was designed by London Transport and built by the Associated Equipment Company (AEC) and Park Royal Vehicles. The first prototype was completed in September 1954 and the last one was delivered in 1968. The layout of the vehicle was conventional for the time, with a half-cab, front-mounted engine and open rear platform, although the coach version was fitted with rear platform doors. Forward entrance vehicles with platform doors were also produced as was a unique front-entrance prototype with the engine mounted transversely at the rear.