Yet car ownership in Beijing is still growing by about 200,000 a year. The only solution to this challenge is the continuous development of the city's public transport system along the lines already implemented by the authorities, but with one important addition - charging for traffic congestion. This will ration road space by price, so that the marginal cost of an additional trip by a car owner will be paramount in his/her mind.

The introduction of such a scheme in London in 2004 by Ken Livingstone, then mayor of London, reduced the number of vehicles entering the central part of the city by 70,000 a day. This has produced real benefits for the city, not only by cutting key traffic pollutants but also by improving public transport capacity and performance, and reducing road traffic casualties.

I have always argued that the geography of Beijing, with its five ring roads, would lend itself very easily to congestion charging. A congestion charge zone could be introduced within either the Second or Third Ring Road at the beginning and then extended outward depending on the success of the scheme and public demand for it.

As in London, to win public support, the funds raised from the congestion charges would have to be reinvested in public transport, and some exemptions or at least discounted rates need to be given to residents within the zones. This also would be consistent with the government's focus on people-centered and scientific methods of development.

The author is deputy chair of the Environment Committee, London Assembly.