2001 sees the celebration of two significant milestones in British transport history; the 200th anniversary of the first motorised passenger carrier and the 150th anniversary of the first double-decker bus.

The distinguished West Country mining engineer, Richard Trevithick, made the first motorised passenger carrier at the early stages of the nineteenth century. It was powered by steam and ran between Camborne and Tuckingmill in Cornwall.
However, it was not until 1851 that, due to the popularity of the Great Exhibition, a roof and second storey were added to the single-storey horse-drawn carriages of the time.
A novel form of transport and a way to ease the congestion on the streets, the double-decker bus was born.

http://www.royalmail.com/default.htm