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February 13, 2006 10:48 am

Capita takes tried and tested route

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In a quiet side street, next to a car park and a brightly painted food van, is a controversial building.

Two floors of it are devoted to making drivers pay £8 a day for something they once used free of charge: central London’s roads.

Neither the company’s name, nor the words “congestion charge” appear anywhere and the location is kept secret. The charge has been the subject of howls of protest from the motoring lobby, city centre businesses, and elements of the press.

But three years after launch, it has been hailed in other quarters as one of the most successful public sector IT projects in the UK, and authorities in other areas, such as Greater Manchester and Bristol, are considering similar schemes.

No regular driver in the centre of town could deny that congestion was a problem. Traffic speeds were no faster than a century ago.

That meant that a steep congestion charge might be grudgingly accepted, but an incompetently administered one would never be.

So how did Capita, the company behind the scheme, manage to make the charge work? It is a combination of older, robust technologies, rather than cutting edge systems, and a few hard working people to sort out the problems the machines cannot handle.

“We made the right decision to go with some proven technology – number plate recognition – rather than listening to the sales people who were saying ‘We can deliver you the earth’,” says Malcolm Murray-Clark, director of congestion charging at Transport for London (TfL).

The core of the system is a network of infrared cameras pointed at roads and junctions across the charge zone, which covers 21 sq km of central London.

In the dark winter evenings, number plates are hidden by the glow of headlights. But in infrared they stand clearly enough for the vast majority to be automatically read by computer. These are then checked against a list of people who have paid and the unpaid ones receive a £100 penalty charge notice.

There are some smart algorithms which resolve the most obvious errors. For example, if the A of number plate ABCD 123 was partially covered by another car, the computers might register two plates: ABCD 123 and BCD 123.

If it detects both in the same location within 10 seconds of each other, it is almost certainly an error so the shorter reading can be deleted.

Records the computers cannot resolve are examined by a team of six, who sort through 24,000 a day, sometimes as many as 700 an hour.

On one of the anomalous plates, for example, it looks like the driver has crudely converted an F to an E with a piece of black tape in an unsubtle attempt to evade the charge.

The infrared picture can be cross-referenced with colour video of the same car. If the licensing record for the number plate (minus tape) matches the colour, make and model of the vehicle in the video, it is pretty clear whose car it is, and the owner will receive a penalty notice.

This system keeps the number of mistakes to a minimum. “Less than 1 per cent of penalty charge notices wind up with an appeal, and TfL wins about 70 per cent of appeals,” says Colin Cross, the business director responsible for the scheme at Capita.

For legal reasons, all the site’s records have to be stored on media that can only be written once and not altered. So at the heart of the server room are eight HP optical disk units. The same size and shape as washing machines, they certainly are not cutting-edge storage equipment but, like the cameras, they are reliable, which is more important.

Government estimates suggest congestion within the zone has fallen 30 per cent, and traffic during charging times is down 18 per cent.

But congestion remains a problem across London and much of the UK, and various high-tech schemes are being prepared to combat it. As a first step, the charge zone is due to be extended westwards in 2007, to cover the Chelsea, Kensington and Notting Hill areas.

With this second roll-out, comes a chance to build in more effective technologies. TfL and Capita are considering smarter cameras.

Currently, each camera has two expensive permanent fibre optic links, sending a live video stream to the London headquarters and the Docklands disaster recovery centre. The new cameras will process most of the images themselves so will not have to send as much data to headquarters and will only require a much cheaper, broadband cable.

At the time of the original contract, TfL looked at some more advanced technologies, such as a microwave tag system which powers Austria’s motorway tolls.

This was considered too risky for first London project but it is now being tried in Southwark and is likely to be implemented in 2009, when the current contract is up for renewal.

TfL is also looking at satellite based systems which use a secure receiver carried aboard a car to track where it has been and hence how much it should pay. However, the tall buildings and narrow streets of London mean that the current US-owned GPS satellite system is not effective.

It will have to wait for Galileo, the forthcoming European satellite positioning system, says Mr Murray-Clark. “GPS is very difficult in an urban environment. The new Galileo satellites will make it easier,” he says.

Eventually, a combination of cameras, microwave tags and satellites could be the basis of a complete, integrated road pricing scheme to cover the whole of Europe.

It would charge road users on the basis of how much they travel, the type of car they drive, the time of day, and perhaps even the number of passengers and traffic levels on the road at that time.

Some will resent it, others will view it as a necessary answer to the congestion problem. Either way, it will certainly be easier to accept if the charges are efficiently administered.

So why all the security? “It’s appropriate to any site where large amounts of sensitive customer data are stored,” says Mr Cross.

In any case, the London scheme is much less unpopular than at first feared.

At least the congestion charge is fair and effective – an impressive achievement in itself.

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