As we approach the first anniversary of the introduction of the London congestion charge, the most solid sign of its success is to be seen with Labour's decision to re-admit Ken Livingstone, writes Chris Johns.

His adoption as the official Labour candidate in the upcoming mayoral election is another indication of how the controversy over congestion charging has subsided, with many die-hard critics now grudgingly accepting that it has worked pretty much as it was supposed to.

According to the polls, two-thirds of Londoners now think that congestion charging is a good idea. The mayor has embarked on a consultation process that could result in an extension of the charging zone westwards into Kensington and Chelsea.

Livingstone's fame has spread internationally. "We're going to have to do what Ken Livingstone did in the city of London," said Canada's environment minister, David Anderson, as recently as this week.

The statistics are impressive - even when we adjust for the fact that they come from the mayor's office. Every day, 50,000 fewer cars are entering central London, a fall of 16 per cent. Most car users have simply switched to buses, tubes and taxis, with little evidence of a significant fall in the absolute numbers of people entering the centre of the city. Retailers and other small businesses complained at first but no longer seem to be quite so concerned.

Accident rates are down by almost 20 per cent. Bus journey times have dramatically improved - using London buses is now a pleasure, something I haven't been able to say since I was a student here in the 1970s.

The introduction of compulsory pre-paid bus tickets has been very effective and has made a significant contribution to faster journey-times (Londoners cannot buy a ticket on the bus, thereby allowing the driver to drive). Like the congestion charge itself, pre-paid bus ticketing was widely forecast to be a disaster.

The success of Livingstone's bus strategy is the most surprising outcome of the congestion charge. It is not what he intended. His first aim was to invest heavily in the London underground, something that Tony Blair stopped him from doing. Tube use fell by 1 per cent last year, the only surprise being that the fall wasn't greater, so bad is the service.

By contrast, bus use rose and, in terms of the number of passenger journeys, is now higher than at any time over the past three decades. Just how sustainable this switch to buses is remains to be seen; serious money has to be spent on the underground.

Overall congestion rates are back to where they were 20 years ago. This doesn't just mean we can move around central London with much more freedom. Presumably, pollution levels are down, although hard statistics on this are hard to come by. If buses are cheap and cheerful, taxis are expensive but plentiful.

In one sense, the congestion charge has been too successful. Revenues have not been as strong as had been forecast. Another problem has been the performance of the company that won the contract for implementing the scheme.

Capita had its contract hastily revised last year, was persuaded to invest much more heavily in infrastructure, particularly in IT, and is now subject to stringent financial penalties if targets are not met. Some reports suggest that they are still failing and they could be gone by April. The company has expressed surprise at these suggestions.

Even the perennial problem of roadworks seems to be managed with a little more sanity, although I don't know whether Livingstone can claim credit for this. Over the past few weeks, as rush hour draws to a close, huge road maintenance vehicles start to appear in side roads around Piccadilly and Regent Street.

Resurfacing of these main arteries is taking place entirely at night. By the start of the morning rush hour, the dozens of JCBs and other assorted monsters have mysteriously disappeared and the roads, although not exactly smooth, are perfectly passable. For once, somebody seems to have thought things through.

One of the many ironies of Livingstone's transport strategy is just how good all of this is for business. The right-wing press still detests the mayor for his loony-left past and still attacks him at every opportunity. Michael Howard has pledged to scrap the congestion charge if London gets a Tory mayor.

Livingstone still provides the media with plenty of ammunition with some of his weird beliefs. But, pragmatically, it becomes increasingly difficult to have a go at someone who is doing so many things right. Here is a forecast: when Ireland is finally forced to scrap vehicle registration tax, it will be replaced by a congestion charge in each of the three main cities.