If you want a problem solved, beware politicians bearing gimmicks. For more than seven years, Boris Johnson has made the bicycle the symbol of his mayoralty and an emblem of his political style: reassuringly traditional but green and modern. That is politics for you. But it has nothing to do with the pressing problems London faces in transport policy.

It is 12 years since the congestion charge was introduced in London — yet the centre of the city is often at a standstill, sometimes for reasons that defy common sense. I recently counted 15 buses on the Strand, which runs east from Trafalgar Square all the way to the Law Courts. Six of them were empty. The capital has more than 66,000 private hire drivers [IS THERE A SOURCE FOR THIS?], distinct from black cabs, summoned all over the city centre by iPhone apps or controllers in grubby offices. Do we need so many? And who truly believes the planned “cycle superhighway” along Victoria Embankment will do anything but slow the miserable snake of cars along the river to a near standstill? Not everyone cycles, Mr Johnson.

London’s often imbecilic transport arrangements are a serious problem for a global city that is the engine of the British economy and a magnet to commercial companies and creative geniuses who want to live and work in the country. That allure remains powerful. But we dare not take it for granted. A city that is impossible to move around rapidly loses its charm for men and women who can afford to live anywhere.