Buses play a major role in the public transport of the United Kingdom, as well as seeing extensive private use. While rail transport has increased over the past twenty years due to road congestion, the same does not apply to buses, which have generally been used less, apart from in London where their use has increased significantly. Bus transport is heavily subsidised, especially in London. In 2014/15, there were 5.2 billion bus journeys in the UK, 2.4 billion of which were in London.
The first omnibus service in the United Kingdom was started by John Greenwood between Pendleton and Manchester in 1824. Stagecoach services, sometimes over short distances, had existed for many years. Greenwood's innovation was to offer a service which did not require booking in advance, and which picked up and set down passengers en route. Greenwood did not use the term omnibus, which was first used in France in 1826.
In 1829 George Shillibeer started the first omnibus service in London. Over the next few decades, horse bus services developed in London, Manchester and other cities. They became bigger, and double deck buses were introduced in the 1850s. The growth of suburban railways, and later horse trams (from 1860) and electric trams (from 1885) changed the patterns of horse bus services, but horse buses continued to flourish. By 1900 there were 3,676 horse buses in London.
There were experiments with steam buses in the 1830s, but harsh legislation in 1861 virtually eliminated mechanically propelled road transport from Britain until the law was changed in 1896. From 1897 various experimental motor bus services were operated with petrol-driven vehicles, including a service in Edinburgh which ran from 1898 to 1901. In 1903 motor bus services were started in Eastbourne, and in the same year a motor bus service was started between Helston and The Lizard by the Great Western Railway .
Motor bus services grew quickly, and soon eclipsed the horse buses. Early operators were the tramway companies, e.g. the British Electric Traction Company, and the railway companies. In London, the horse bus companies, the London General Omnibus Company and Thomas Tilling, introduced motor buses in 1902 and 1904, and the National Steam Car Company started steam bus services in 1909. By the time of the First World War, BET had begun to emerge as a national force.