William Rees Jeffreys

William Rees Jeffreys (1 December 1871 – 18 August 1954) was a British cyclist and early campaigner for road improvements who became a key figure in the early 20th-century development of the UK highway system. As honorary secretary and later chairman of the Roads Improvement Association and the first secretary of the Road Board (which in 1919 became part of the Ministry of Transport), he was an early advocate of a ring road around London, and helped instigate the British road numbering system. In 1937 Jeffreys was described by former UK Prime Minister David Lloyd George as "the greatest authority on roads in the United Kingdom and one of the greatest in the whole world."

A charity he founded in 1950, the Rees Jeffreys Road Fund, continues to support UK transport-related projects.