A double-decker bus is a bus that has two storeys or decks. Double-decker buses are used for mass transport in the United Kingdom, Europe, Asia and many former European possessions, the most iconic example being the red London bus, namely the AEC Routemaster. Early double-deckers put the driver in a separate cab. They were vastly used in Sri lanka transportatiion. Later these busses began to stay out of Sri lankan roads.