In recent years, there have been two sets of traffic jams each morning at London’s Hyde Park Corner. One, on the circle of roads at the busy intersection, is made up of cars, buses and trucks. Meanwhile, on paths leading across the roads, scores of cyclists wait for the lights to change. When the traffic is stopped, they surge across and either down nearby Constitution Hill or into Hyde Park.

The junction is one of the places where a massive resurgence of cycling in London in recent years is most obvious. This has benefited from the desire of Transport for London (TfL), the London mayor’s transport authority, to promote both bicycle use and walking, the only urban transport modes that produce virtually no carbon emissions or pollution. The average number of daily journeys by bicycle in London increased 91 per cent over the eight years from March 2000.