Paul Barker: Mr Livingstone has reinvented the poll tax

With Mayor Livingstone's imminent introduction of the congestion charge, the nation's capital will be plunged into one of the most drastic experiments in top-down urban management since the road engineers of the 1950s and 1960s built the great ring of flyovers and multiple roundabouts at every approach to London. The physical evidence from that era is all around you if you enter or leave London by car, bus or coach: the Hammersmith flyover, the Westway urban motorway, the Euston Road underpass, the Aldgate roundabout, the Elephant and Castle figure-of-eight intersection. You could chant these names like a chart-topper song by Madness.

They are urban battle scars, marking places where viable neighbourhoods were destroyed. They are also a reminder that the conventional wisdom of the day is usually wrong. Those road engineers weren't evil men. They thought they had the best solution. Politicians merrily nodded the work through.

The conventional wisdom has now shifted 360 degrees. Drivers must be kept out, not helped to get in. London must be purified and made to fit into some ideal version of a city. The model appears to be something Tuscan or Umbrian: Siena or Urbino, say, on a quiet afternoon. This may turn out to be as inept a comparison with a sprawling, vigorous city like London as the road engineers' earlier comparisons with car-laden Los Angeles or New York. But on Monday 17 February, the great experiment begins. The computers will be switched on. To enter central London between 7 am and 6.30 pm on a weekday, you'll have to pay a daily charge of £5 or face a fine. Paradoxically, it comes as more new cars are being sold in Britain than ever before (2.56 million in 2002). A democratic dilemma.

This time the manipulation is electronic, not reinforced concrete. But will it work any better? As always with electronics, we'll get the answer very swiftly. Arguably, all you need to know is that the private contractor managing the scheme is Capita. This is the firm that last autumn brought us the débâcle over checking teachers' and social workers' criminal records. It oversaw the collapsed government scheme for individual learning accounts. It failed dismally to manage housing benefits in more than one London borough.

Capita has already succeeded in falling out with the Royal Mail over plans for drivers to pay the charge at post offices. This will pile on the pressure at call centres. It is also reported that, of the 40,000 residents within the zone who own cars, only three thousand have registered for their 90 per cent discount. (It's not enough simply to be on the electoral register.) This means they will unwittingly start to clock up fines from day one, till the first automated penalty demand arrives. Nor do most disabled drivers seem to know that they must register. (It's not enough to have an orange badge.) For a world-class recipe for chaos, you must stir in the vast number of cars which are unlicensed, untaxed, borrowed or stolen.

Fiscally, the best comparison is with the poll tax. For this, also, there were sound theoretical arguments. But they all crumbled immediately it was put into practice, and the lethargic citizenry woke up to what it meant. The comparison is precise because both the poll tax and the congestion charge are regressive policies, hitting the poor hardest. Insofar as the charge does hurry traffic up – likely to be a tiny and temporary gain, if it happens at all – the beneficiary will be the speeding business driver who'll seek to set the charge against tax.

Mr Livingstone has no other direct powers to raise money. He can levy a precept on the London boroughs (which they will contest), or he can try to woo more cash from the Treasury (which they will resist even more fiercely). Hence, behind the ecological flim-flam, his case for the so-called congestion charge. In reality, it's a simple flat rate tax on cars, and the funds will flow into the mayor's coffers. We'll wait years to see how much of it goes into better public transport, and not into the backwaters of administration. And we must factor in the Lottery Effect – if an institution gets money from some new source, that's the golden moment for the Treasury to scale down existing grants.

It's hardly surprising that no other city of London's size and complexity has tried to introduce such a charge. The only close comparison is Singapore. But the political regime in Singapore is Fabian Authoritarian. If you're told to jump, you jump. London is an anarchic city. That's its vigour and its appeal. A few small traffic jams never did anyone any harm. What is going to happen in rat-runs around the edge of the charge zone will make any recent jams pale into insignificance. And the city centre will become even more of a tourism theme-park than it is now: a place to wander around in, getting boozed up. Think Leicester Square, that grimy and even ominous experiment in pedestrianisation, but on a much larger scale.

Of course, it may run like clockwork – a much more reliable mechanism, you might think, than Capita's electronics. Or again, pigs may fly. Londoners will no doubt see Livingstone's car tax off, as they have many previous urban grand designs. I only hope it doesn't do too much damage to the fabric of the city's life in the meantime.

The author is a Senior Research Fellow at the Institute of Community Studies