Light at the end of the tunnel of Britain's transport policy

In the road-traffic statistics published by the Department for Transport yesterday, an intriguing trend has emerged. For a long time it has been assumed that the number of vehicles on the roads will grow roughly in line with the economy as a whole.

In the road-traffic statistics published by the Department for Transport yesterday, an intriguing trend has emerged. For a long time it has been assumed that the number of vehicles on the roads will grow roughly in line with the economy as a whole.

That was what happened during the Eighties. And between 1990 and 1992, when the economy stalled, there was no growth in road traffic. But in the decade since then, in the careful words of the Government's statisticians, road-traffic growth has been partially "decoupled" from economic growth. While the economy grew by more than 25 per cent, road traffic was up by only 15 per cent.

This is a hopeful, if limited, sign. The growth in road traffic has to stop somewhere, but the difficulty has always been – as Ken Livingstone is discovering – how?

The statistics suggest that one of the arguments against congestion charging, that it will damage business, is off target. Eventually, businesses will adapt to the fact that road use has additional costs, whether they are paid for in the form of congestion charges or in the form of time waiting in traffic jams. When the economy grew in the Nineties, businesses used the roads more efficiently, so that traffic did not increase as much as expected.

That does not mean that Mr Livingstone's scheme for central London is a good idea – it will most likely simply shift congestion to just outside the boundary and throw up an inefficient bureaucracy of enforcement. It is also unfair and, with just one month to go, highly confusing.

But it does mean that there is some hope of eventually weaning our car-dependent economy off its addiction to roads. The other hopeful figures in Transport Trends are those for rail travel, which is up by 29 per cent since privatisation. The way the railways were sold off was botched, and we are yet to be convinced that Network Rail is the right structure, but passenger numbers are the ultimate test and they are moving in the right direction.

Once economic growth has been fully "decoupled" from road traffic growth, we have a chance of raising living standards without ever-increasing damage to the environment.