In 1969, the idea of using a park and ride system instead of relief roads to serve people travelling into Oxford was thought to be unworkable.

City engineer Tom Morris told a public meeting: "It seems nice in theory to tell people to park their cars and get on a bus, but it does not work in practice."

But by the early 1970s the mood had changed, with the realisation that the city centre was finding it difficult to cope with the increasing number of cars.

Park and ride became the key element in the balanced transport strategy adopted in 1973 by the city and county councils, which decided to improve conditions for cyclists, pedestrians and bus passengers, instead of concentrating solely on drivers.

Oxford pioneered the park and ride system which has since been adopted across the world.

The strategy followed much debate in the 1960s about how to solve the city's transport problem largely blamed on commuters parking in the centre.

Redbridge, off Abingdon Road, was built on the site of a former tip. On the day it opened, in December 1973, it attracted fewer than a dozen people. But within a week, 2,000 shoppers had used the 250-space car park.

Noel Newson, the county council's group manager for sustainable transport, said: "Over the years, the system has been a real success."