The idea was adopted by then transport minister Ernest Marples, and led to a rash of urban motorways, underpasses, one-way streets, flyovers, and in more ambitious cases, such London Wall in London, strings of high-level walkways.
Buchanan also suggested a congestion charge in cities, an idea that has been take up by London mayor Ken Livingstone.
Buchanan was never a pure highways engineer. Instead, he set out to provide technical solutions for urban problems. As a civil servant, he also served as a town planning inspector, and in the 1960s he presided over a public inquiry into a vast modern complex at Piccadilly Circus, which he turned down in his report.
In the same year as Traffic for Towns was published, he left the civil service to became Britain's first professor of transport at Imperial College in London. A year later he set up his consultancy, Colin Buchanan and Partners, which was taken over by his son Malcolm on his retirement in 1983.
Buchanan was president of the Town Planning Institute in 1964 and of the Council for the Protection of Rural England from 1980 to 1985.