Hello, Ken. Goodbye, Oxford Street

D-Day - Tubes and trains are overcrowded, suburbia is ignored, and commercial areas are in decline.

I looked with amazement at the headline on the London Labour Party's glossy election leaflet that plopped through my letter box. It said: "Ken or cuts." The People's Ken has never been short of chutzpah. If he's re-elected, the real message is more likely to be "Ken and cuts".

Any retrospective on Livingstone's mayoralty must begin with his manifesto for the 2000 election. In it, he said that "to solve the crisis of London's transport system" was his "single most important priority". The clearest public evidence of delivery is the buses flooding on to inner-London streets. But Livingstone also committed himself to freezing, or at least holding down, all fares. Transport for London, the integrated agency responsible for the city, now faces an immediate shortfall of £1bn on an annual turnover of £4.5bn. The TfL board is quietly panicking. Barring a sudden wild upsurge of government grants, many of those extra buses will go into cold storage, or fares will rise drastically (perhaps with charges scaled differentially for peak and off-peak travel). Or both.

This has all been put off until after the election. Whether the new mayor is Livingstone, Steve Norris or Simon Hughes, he will face an identical dilemma. Norris's plans to abolish the congestion charge and to put conductors back on buses make the sums worse: less revenue, more costs. But that may be just electoral fluff. Last time around, Livingstone also promised to "start to get conductors back on buses". That commitment vanished in the usual cloud of Livingstone PR: his press team is larger than Downing Street's.

The 2000 smorgasbord of promises included a vow to tackle overcrowded Tubes and the railways. Yet these have got worse. I hope you are not trying to read this article in the middle of that regular London off-peak phenomenon, four years on: an elbow-to-elbow mid-morning or mid-evening train.

Livingstone dribbled away time and money battling against the semi-privatisation of the Tube. It was always clear that, right or wrong, it was central government that had the legal powers.

"The trouble with Ken," an exasperated specialist remarks, "is that he doesn't know how to make anything work. He just knows how to spend." This brought down his Fares Fair scheme in the 1980s when he was leader of the Greater London Council. The outer-suburban borough of Bromley halted it with a legal challenge: it was paying for price cuts from which it got little benefit.

This time around, Livingstone again stands accused of being "the mayor for Zone One" (the inner-London fares area). The congestion charge - of which more in a minute - shows no sign of halting the inexorable 2 or 3 per cent annual rise in traffic. The policies of Transport for London show little interest in the suburbs, where traffic jams can be horrendous. The feeling seems to be that car drivers are just naughty boys and girls who should be punished, even though most people drive only when it is the rational way to get from A to B.

The congestion charge is always presented as the jewel in Livingstone's crown. He deserves credit for pushing it through: it did not produce anything like the predicted revenue, but it did cut back on car traffic in its small slice of inner London. The remaining traffic, especially taxis and buses, moves a bit faster.

The long-term impact is harder to judge. The economic effect is a serious worry. Is the economy of London infinitely malleable? A TfL study, carried out in-house, dismisses these anxieties. More convincingly, Professor Michael Bell of Imperial College London carried out an independent scrutiny of John Lewis's flagship store on Oxford Street. He concluded that the congestion charge had cut sales "by between 5 and 9 per cent, after allowing for other factors, in particular the closure of the Central Line". Bell argues that, with the charge, "the decline of Oxford Street will be hastened".

Livingstone claims to be concerned about the capital's economy. But this concern seems to focus on wishing to pepper the London skyline with more high-rise office blocks. Some spatial canards never go away. The mayor praises "the role that well-designed tall buildings can play in delivering a sustainable, compact city". This takes you back to the argument for the disastrous council-flat tower blocks of the 1960s. Given the space you need to put around them, and the internal demands of lifts and plumbing, no space is saved. It is chutzpah - in glass, steel and concrete.

Livingstone has been consulting publicly about extending the congestion charge westward to Earls Court. But there is no money for this: the post-election decision is expected to be "postponement", at best. This wider zone is not the only pipe dream. The International Olympic Committee, in admitting London to the 2012 Games shortlist, fretted about the city's transport system. A new Hackney-to-Chelsea Tube featured in that 2000 manifesto: it would be handy now for the Lea Valley Olympic site. But it is at least 25 years in the future. Four years on from the first mayoral election, the Liverpool Street-to-Paddington "Crossrail" scheme also remains in the pending tray. Even the ultra-modest East London Line extension into the edges of Hackney (inner London's only borough with no Tube station) has stalled. The so-called cross-river tramline from Camden Town to Waterloo is only a line on a map. No work has been done on it.

And so the story goes on. The idea was that the Greater London Authority (GLA) would be a tight-knit body, a far cry from the GLC. But Livingstone keeps trying to edge into territories that are not his direct responsibility, or where his impact can be marginal at best, at the expense of his real responsibilities. There is an Older People's Strategies Group; a London Health Commission; on education, he proliferates task forces, co-ordination committees and action zones. Even over affordable housing, there hangs a question mark. Unlike the GLC and the London County Council before it, the GLA cannot build houses. The Livingstone scheme is to use GLA "strategic targets", passed on to the boroughs, in order to force developers to build cheap or social housing on their own land. In the present housing boom, where developers can easily pass on any extra costs to other housebuyers, it may work. When there is a slowdown or a downturn, however, we will be back to the old snag in such strategies. People who have accumulated land will sit on it until policies change.

For my money, Livingstone's greatest and most enduring success - the real jewel - is one of the most modest. Trafalgar Square comes directly under the control of the mayor. Opening it up on the north side has turned a grim enclave into a delightful new space. The architect on the nine-month project was Spencer de Grey, of Foster & Partners. He told me he was walking around the reshaped square when he overheard a female visitor talking to a friend. She looked up at the handsome new stone stairs that lead up towards the National Gallery. "Have they always been there?" she wondered aloud.

"I couldn't have wished for greater praise," de Grey said.

It is a model of the way to reshape an old city which lives by its own dynamic.

Paul Barker is a senior research fellow with the Institute of Community Studies