Congestion is wonderful: it is a sign of wealth, and a progressive tax

'Britain has quite low car ownership compared with other countries of comparable income levels'

Traffic congestion is a good thing; congestion charges are unfair, benefiting the rich and hitting the poor.

Traffic congestion is a good thing; congestion charges are unfair, benefiting the rich and hitting the poor.

There are certain things good liberals are not allowed to say and those two propositions rank high among them. How could sitting in a traffic jam possibly be good? How could charging the sort of prosperous people who drive into central London or race up the M40 and using the money for better trains be bad? In fact, if you look at why congestion occurs and how congestion charges will work out in practice, the popular "sensible" views are actually profoundly hypocritical.

Start with congestion. Now of course it is no fun to sit in a jam. It would be absurd to pretend it was. But it is equally no fun to live in a country that doesn't have them, for road congestion is an inexorable and inevitable part of increasing prosperity. It is, as Ronald Reagan (among others) said of old age, "fine, when you consider the alternative". Thus Luxembourg, the richest country in Europe, has the highest car ownership in the world; Afghanistan about the lowest.

As people get richer they spend an increasing proportion of their income on travel, enjoying being able to move swiftly both within and between countries as one of the great freedoms of our age. And for most people, for most journeys, the car is the technology they use to experience that freedom. That is why there were more cars sold in Britain last year than ever before in our history, and incidentally, more built than in any year since the early 1970s.

But more cars cause more traffic congestion. Sensitive road building programmes will reduce it a bit but there are physical limits to that, especially in towns. Real cycle lanes, instead of lines painted on roads, might enable a few more people to cycle instead of drive. More reliable trains might take a few more off the roads too. But we would be kidding ourselves if we think that any other technology available at the moment will make a material difference to the number of cars on the road. At best we might slow down the growth a bit.

What do you say to people who fret about congestion? You ask them what they would rather have instead. Would they rather be poorer, so they could not afford to travel so much? Not many would vouch for that. Would they like the cities to be empty of cars for ordinary people with special lanes for the nomenklatura, like Communist Moscow? Surely not.

If they were really honest, they might admit they would rather live in a world where other people did not use their cars so that they could do so more easily. But usually they retreat to the argument that if only public transport was better they would not use their cars so often. It is a nice idea that ignores the fact that for most car journeys public transport is not a practical option: ever tried to do the weekly supermarket run on the bus?

So the car is also a great social leveller. Sure, some people like to display their worldly success by having a decent car, just as others do so by wearing designer clothes, living in expensive houses or buying titles from the government. But the practical effect on anyone's life from buying an expensive car rather than a cheap one is quite small. Both do the same job, and for 90 per cent of journeys do it in the same time.

Congestion, too, is a great leveller, for sitting in a jam we are all equal. Or rather we are not exactly equal because the time of people working long hours or earning high salaries is worth more. So congestion in practice is an extremely progressive tax: it bears most heavily on the rich.

That leads to proposition two. Congestion may be better than the alternative, but there still ought to be a case for trying to alleviate it. If this is to be done by thoughtful and environmentally sensitive road-planning then fine. Britain has, by the standards of most developed countries, under-spent on roads both in terms of quality and quantity. The result is that, though the UK has quite low car ownership compared with other countries of comparable income levels, it has rather worse road congestion and a fair degree of environmental blight. But would charges help?

Well, as far as Ken Livingstone's charge to enter central London is concerned, it would help the rich – but only a bit. Insofar as it reduced traffic it would make it easier for people who are prepared to pay to have clearer roads, at the cost of making things a bit less pleasant for those who don't want to pay, or can't. But at the proposed £5-a-day charge, most people would either stump up to what is just another tax, drive round the central zone (and so transfer the congestion elsewhere) or choose a restaurant, a shop or a job somewhere else. It would be just one more cost of running a business – and a life – in central London.

And the alternative of public transport? Well, there are powerful arguments in favour of improving London's transport system, but those arguments stand irrespective of congestion charges. The charges, if you deduct the cost of the Mayor's new offices and staff, will make hardly any net contribution to transport funding.

As for the other anti-congestion proposal now being touted – motorway tolls – that, too, would simply add a bit to the cost of getting around both for business and for leisure. There are plenty of arguments in favour of trying to improve alternatives to the car. One of the great innovations of the past five years has been the work of the "no-frills" airlines in cutting the costs of airfares, thereby making a flight from, say, London to Prestwick, a cost-effective alternative to driving. The Channel tunnel, though, unlike the cheap airlines, a commercial failure, has similarly expanded the market for travel to France and Belgium.

All this is at the margin, however. The key point is that last year people voted with their chequebooks to buy more cars than ever before. They bought them to use them. They bought them despite Britain having just about the most expensive petrol in the developed world. And they will go on buying them – as people in very developed country do – and causing more congestion as a result. Unless...

The one thing that would fix the problem, of course, would be a socking great recession. You want that?