Road signs in the United Kingdom and in its associated Crown dependencies and overseas territories conform broadly to European design norms, though a number of signs are unique: direction signs omit European route numbers and road signs generally use the Imperial System of units (miles and yards), unlike the rest of Europe (km and m). Signs in Wales and parts of Scotland are bilingual.
A range of signs are used on British roads such as motorway signs, warning signs, and regulatory signs.
History
Modern British road signage can be traced to the development of the "ordinary" bicycle and the establishment of clubs to further the interests of its riders, notably the Cyclists' Touring Club (CTC), the National Cyclists' Union (NCU) and the Scottish Cyclists' Union (SCU). By the early 1880s, all three organisations were erecting their own cast-iron "danger boards". Importantly, these signs warned of hazards, rather than just stating distances or giving direction to places, acknowledging the fact that cyclists, like modern motorists, were unlikely to be familiar with the roads they were travelling along and were moving too fast to take avoiding action without prior warning. In addition, it was the cycling lobby that successfully pressured the government in 1888 into vesting ownership of and responsibility for roads with county councils in previously established highway districts that would be funded from taxation rather than tolls. The districts were active in the erection of semi-standardised directional signs and mileposts in the latter years of the 19th century.
The rise of motoring after 1896 saw the pattern repeated. The larger motoring clubs, notably The Automobile Association (AA) and the Royal Scottish Automobile Club (RSAC) erected their own, idiosyncratic warning boards and direction signs on a wide scale. Under the Motor Car Act 1903 four national signs were created which were to be set at least from the ground and from their reference point. These signs were distinguished based on their shape, rather than a symbol or writing on them. These included a white ring meaning speed limited (as marked on a small information plate below it); a white (sometimes red) diamond for a "motor notice" such as a weight restriction (given on a plate below); a red disc for a prohibition; and a red open triangle for a hazard or warning. The latter two could provide more detail by having an information plate below them, but often it was left to the motorist to guess what the sign was referring to, and it was common to have variations between different local areas for what was a prohibition or just a "notice". This format was to develop into the British road sign that was standard from 1934 until 1964. Before this time regulations for traffic signs were published under powers created by the Road Traffic Act 1930 and so national road signage specifications were only advisory.
Following a review of national signage in 1921, a limited number of warning and hazard information plates also used symbols, rather than only text. Such symbols had been developed in continental Europe as early as 1909, but before this had been dismissed by the UK which favoured the use of text. The symbols were simple silhouettes which were easy to recognise at a distance. Some were unusual, such as 'SCHOOL' (and later 'CHILDREN') was depicted by the 'flaming torch of knowledge'. The government made increasing efforts to standardise road signs in the Road Traffic Act 1930 (RTA) and regulations of 1933, being finally consolidated with the publication of the 1934 Road Traffic Acts and Regulations handbook. These saw the end of non-standard permanent signs being erected by motoring clubs, such as the black and yellow vitreous enamel AA signs (although this did not include temporary direction signs). While the RSAC had ceased erecting signs, the Royal Automobile Club (RAC) had begun to do so to RTA specifications (save for the inclusion of the RAC badge) and was very active in this respect in the late-1930s.