Inside London's Congestion Charging hub

Like it or loathe it, London's Congestion Charge has been a success. There has been none of the civil disobedience predicted by critics and no major faults allowing drivers to get away without paying.

silicon.com was given an exclusive tour of the Congestion Charge imaging hub, to find out how the groundbreaking system operates.

The aim of the scheme, which went live in February 2003, was to reduce traffic by 15 per cent and speed up journey times by 25 per cent by getting people to shift to public transport.

This would be done by charging drivers who travelled through the zone, policed by a network of cameras which would spot and fine drivers who didn't pay up.

Capita was awarded the deal to build and operate the scheme by Transport for London (TfL) - but only had 11 months to get the system up and running, a "phenomenally short time period" according to Colin Cross, Capita's congestion charging scheme business director.

Developing the system took the equivalent of 450 man years and brought together more than 30 suppliers. And it had to work from the first day.

Cross said: "The time scales were so tight and everyone was expecting this to fail. There were predictions that London would grind to a halt. But it worked from day one. There was no precedent for this - it was a true green field service delivery."

One key reason for success is that the requirements didn't change too much, Cross said. And another reason was the support of London's mayor Ken Livingstone: "One of the reasons the scheme has been successful is the mayor. It needed strong political will to get this going."

Since the scheme launched, according to figures from TfL, traffic has been reduced by 15 per cent and congestion by 30 per cent, while accident rates have dropped by five per cent.

Drivers (with some exceptions) have to pay £8 per day to drive through the zone during its hours of operation . That rises to £10 if you pay between 22:00 and midnight on the day of travel.

At the moment the web payment option is used by 28 per cent of drivers, Paypoint by 28 per cent, SMS by 23 per cent and the call centre by 14 per cent.

Any drivers who haven't paid by midnight are then liable for a £100 penalty charge notice - £50 if they pay in the first 14 days.

Cross said: "What's unique about our scheme is there are no physical barriers to entry. It's a camera enforced scheme. The cameras cover every entry and exit point in the zone - we have 203 camera locations covering every lane of every road."

The cameras are linked by fibre optic to the image processing centre. Black and white cameras are used to record the number plate images while a colour camera captures an image of the vehicle.

Images are sent back to the imaging hub and fed into the automatic number plate recognition system. Overnight a batch run checks the licence plates and strips out the details of vehicles that are exempt or which have paid the charge.

Around one millions images are collected per day, and boiled down to around 10,000 to 12,000 vehicles for which there is no record of payment. These then go on for manual check and then around 5,500 penalty notices are issued every day.

Only two per cent take the fine to an appeal - and fewer than half of them win.

Cross said: "We've seen growth in compliance with the scheme over the last two and a half years and we've seen the number of penalty notices drop. Customers are aware that if they drive into the zone they have to pay because they aren't going to get away with it."

Last year 3.5 million payments were made by SMS, with 170,000 drivers signed up to use it.

"It's the most used SMS channel for financial transactions in the UK," Cross said. "Almost everyone has a mobile phone so you have in your pocket a payment method. It's a very effective channel."

The scheme continues to evolve, with the western extension and with trials of digital cameras using roadside automatic number plate recognition.

Cross added: "We're currently working on the implementation of that extension and that will approximately double the size of the zone."