Leading Article: Right road, wrong reason

FOR ONCE, the Labour Party's irascible transport spokesman is right. The suggestion that motorists should be forced to buy 'motorway permits' for the right to high-speed trips between cities that they can now take for free has nothing to do with transport policy. Rather, as John Prescott observed with his characteristic venom yesterday, it is Treasury policy - dictated by the need to find ways to plug the gaping hole in public finances.

John MacGregor, the Secretary of State for Transport, is well aware that such permits would be unlikely to raise much more than pounds 500m a year (only a hundredth of this year's budget deficit). But those who do not have cars would cheer; and of those who do have cars, 18 per cent use motorways less than once a year and would therefore not care. Much of the money would be paid by hauliers and the employers of travelling salesmen, who would struggle at first then pay up quietly and simply pass the cost on to their customers.

That much is easy to read between the lines of Paying for Better Motorways, the discussion paper just issued by Mr MacGregor's department. It talks of introducing motorway permits of the kind already used in Switzerland and currently under consideration in Germany - and suggests that private motorists might pay between betwen pounds 25 and pounds 75 a year for a permit, with goods vehicles paying 10 times that. Such permits may be justified as a less unpopular way of balancing the public books than closing hospitals or making old people pay for prescriptions; but a strategic transport policy they are not.

Elsewhere in the Green Paper, however, the outlines of a more rational approach to road building in the next century can be discerned. Untolled roads are like unmetered water; if customers have to pay only a flat fee but are then allowed to use them freely without limit, the inevitable result is congestion and waste. The traffic jams on London's M25 are the travelling equivalent of the millions of gallons of water sprinkled on lawns each year by suburban householders who pay a flat water rate.

Since building and maintaining roads costs money, it makes more sense for users to pay according to where and how often they drive, so that decisions on car use - and ultimately the building of roads themselves - are made on the basis of how much each journey is worth to the person who makes it. Until now, it has been hard to put that principle into practice. The act of collecting the charges at motorway tollbooths makes the journey slower and more irritating, and further blights the environment by taking up still more acres of countryside.

New technology raises the prospect of changing all that, the Green Paper explains. In future, cars will be able to glide along the motorways while sensors detect where they are going and charge the driver - either by deducting from the equivalent of a telephone card inside the cabin, or by billing a driver's account at the end of the month.

There will be difficulties aplenty in making such a system work. One will be setting the price: too low, and there will be no incentive for private companies to build new roads; too high, and drivers will quietly switch to the nearest A-road. Another will be factoring in the environmental cost of motorways, which will appear neither on motorists' bills nor in road builders' accounts unless government intervenes. But the Government is right to hint broadly that this is the way forward. It is a pity, though, to put a convincing case for a new policy at risk by imposing a quite separate new tax as a step towards it.