AEC Routemaster

A double-decker bus is a bus that has two storeys or decks. Double-deckers are used primarily for commuter transport, but open-top models are used as sightseeing buses for tourists, and there are coach variants for long-distance travel. They appear in many places around the world, but are presently most commonly used as mass transport in cities of Britain as well as in Ireland, China, Hong Kong, Berlin and Singapore.

The earliest double-decker horse-drawn omnibus appeared in Paris in 1853 and were motorised in the 1900s. Double-decker buses were popularised in Great Britain at the start of the 20th century, with the best-known example being the red London bus, namely the AEC Routemaster. Double-deckers in urban transport were also in common use in other places, such as major cities of India, but were mostly phased out by the end of the 20th century. However, they remain common in Britain as well as Ireland and Hong Kong, while in Singapore and Dhaka they have been introduced and greatly expanded in the aftermath of British colonial rule.

The New Routemaster, originally referred to as the New Bus for London and colloquially as the Borismaster or Boris Bus, is a low-floor hybrid diesel–electric double-decker bus operated in London, England. Designed by Heatherwick Studio and manufactured by Wrightbus, it is notable for featuring a "hop-on hop-off" rear open platform similar to the original Routemaster bus design but updated to meet requirements for modern buses to be fully accessible. It first entered service in February 2012 with Arriva London on route 38.

The original AEC Routemaster was used as the standard London bus type, with a rear open platform and crewed by both a driver and conductor. After half a century, it was withdrawn from service at the end of 2005 (except for two heritage routes which operated until 2014 and 2019 respectively), in favour of a fully accessible one-man-operated modern fleet (including articulated buses), none of which featured a rear open platform. The withdrawal of the Routemaster became an issue during the 2008 London mayoral election with Boris Johnson elected mayor with a campaign pledge to introduce a new Routemaster. Following an open design competition in 2008, Wrightbus was awarded the contract to build the bus at the end of 2009, and the final design was announced in May 2010.