Central London Congestion Charging, England, United Kingdom


The introduction of the Central London Congestion Charging scheme has always been controversial, since it was first introduced in February 2003 to discourage traffic congestion in the city centre and push people towards public transport.

Several commentators have doubted its effectiveness but its keenest proponent, former London Mayor Ken Livingstone, promoted it as a success, as he did in an article in The Guardian newspaper in February 2007 where he commented: "Each day in 2006 there were almost 70,000 fewer vehicles entering the charging zone compared to the number that had been entering each day before charging began.

"The amount of traffic entering central London during charging hours has been cut by around 20%... It has contributed to the growth of cycling, with more people than ever before travelling by bike - there has been a 72% increase in the number of cyclists on the capital's major roads since 2000."

How the congestion charge scheme worked at first

The congestion charge was enforced within a definite road traffic boundary in the City of London. When initially introduced in February 2003, motorists were charged £5 a day to drive through London between the hours of 7am and 6.30pm. The charge is enforced by a network of cameras situated at entry and exit points to the charging zone and at key locations within the zone itself.

Cameras record images of traffic and send them to a central processor to have their number plates read and checked against the list of vehicles that have been paid for. Unless a pass had been purchased in advance or was bought before midnight on the day of travel, the vehicle's registered owner was forced to pay a fine. The charge could be paid via internet, a paypoint at a designated retail outlet, call centre or by mobile phone.

A novel second chance for drivers who forgot to pay by midnight of the day they travel into London was the Pay Next Day scheme. The charge was increased to £10 but the driver has until midnight of the next day to call the Transport for London call centre to pay and avoid a penalty charge notice.

Increased London congestion charges after initial introduction

In February 2007 the congestion charge was increased to £8 a day and the hours were reduced by half an hour to 6pm. The hours were reduced to stimulate the theatre, restaurant and bar trade in the city, which according to Ken Livingstone had not been affected by the earlier introduction of the congestion charge.

In May 2006, in a live TV debate, Livingstone supported a rise in the charge to £10 by 2008. An increase in charges was calculated according to the carbon dioxide emissions of the vehicle, with four wheel drives (4X4s) and larger sports utility vehicles expected to pay £25 a day.

In January 2011 the congestion charges were revised again. If one paid in advance or on the day of travel, then the charge was £10. If paid on the next day of travel, one would pay £12 and if one paid through the congestion charging auto-pay system then the charge was just £9. The discounts and exemptions remained unchanged.

Exemptions to the charges

There are several groups of users and vehicles which were exempt from the Central London Congestion Charging scheme. These included disabled drivers, licensed taxis, minicabs and public service vehicles, motorbikes, mopeds and scooters and emergency service vehicles.

Also, residents in the congestion charging zone paid only ten percent of the charge (£4 a week instead of £8 a day) and cars that are diverted into the zone are not be charged so long as they do not deviate from the diversion.

In addition to this, 'green' cars using alternative fuels (gas, electric, fuel cells and bi/dual fuel vehicles) are exempt from the charge. When the congestion charge becomes based on emissions, owners of larger polluting vehicles living in London receive no discount and would have to pay the full £25 a day, while the list of vehicles with exemption because of low emissions was extended.

Aims of the capital city's traffic scheme

The congestion charging scheme aimed to reduce traffic in central London by ten to 15% and time spent in delays by 20-30%. Prior to the introduction of the scheme, 40,000 vehicles an hour entered the congestion charging zone between 7am and 10am; between 7am and 6.30pm, approximately 250,000 vehicles made 400,000 movements in the zone.

Accordingly the scheme has had a positive impact, as each day in 2006 there were almost 70,000 fewer vehicles entering the charging zone compared to the number which had been entering each day before charging began. The amount of traffic entering central London during charging hours was cut by around 20%. Congestion charging also raises £130-150m a year in revenue (an estimated one third of this in fines), which is used to improve public transport in London.

Central London congestion charging zone

The original congestion charging zone was enclosed within a boundary formed by the Inner Ring Road which consists of: Marylebone Road, Euston Road, Pentonville Road, City Road, Great Eastern Street, Commercial Street, Tower Bridge Road, New Kent Road, Kennington Lane, Vauxhall Bridge Road, Grosvenor Place, Park Lane and Edgware Road. This gave the congestion charging zone an area of eight square miles (21 square kilometres) - 1.3% of the total area of Greater London. There were 203 entry and exit points to the charging zone.

Extension of the congestion charging zone

"In 2008 TfL introduced its new London Low Emission Zone (LLEZ) for lorries entering London. The LLEZ was introduced to reduce the emissions from polluting diesel engines contributing to the poor air quality in the Greater London area."

The western extension of the congestion charging zone was introduced on 19 February 2007, effectively doubling the original area, but it was withdrawn from the congestion zone from 4 January 2011.

The boundary of the enlarged zone started at the northern end of Vauxhall Bridge and (travelling in a clockwise direction) headed along the northern bank of the River Thames as Grosvenor Road, the Chelsea Embankment and Cheyne Walk.

From here, it headed north, along the eastern edges of the Kensington and Earl's Court one-way systems (classified as part of the A3220), encompassing Edith Grove, Redcliffe Gardens, Earl's Court Road, Pembroke Road, Warwick Gardens and part of the Addison Road, before continuing to the A40 Westway as the Holland Road and the West Cross Route.

The boundary then included parts of North Kensington, but the actual boundary was defined by the West London Line railway track, which runs between Latimer Road (inside the zone) and Wood Lane (outside the zone), until Scrubs Lane, before turning east, following the GWR line out of Paddington towards Ladbroke Grove.

Here, the boundary followed the Grand Union Canal and rejoined the existing zone at Edgware Road after skirting Paddington, by way of the Bishop's Bridge Road, Eastbourne Terrace, Praed Street and Sussex Gardens.

Transport for London (TfL) defined some free through routes, where drivers do not have to pay the charge. The main route was defined by the western boundary of the original zone Vauxhall Bridge Road, Grosvenor Place, Park Lane and Edgware Road, with some additions around Victoria. The Westway was the other exempt route.

Extensions to the north, east and south of the city centre were also considered but were not taken forward since their traffic problems were not considered as severe as the west, and in the east and south, public transport provision is not yet considered to be good enough to support congestion charging.

For the western extension significant increases in bus service capacity were introduced.

Effect of London's congestion charge zone extension

Preliminary results of traffic surveys showed that two weeks after the expansion traffic in the extended part of the zone decreased by 13%, which was well within the Transport for London (TfL) predictions of a ten to 15% reduction. This represents approximately 33,000 fewer vehicles entering the expanded area of the zone.

So far the predicted two percent increase in traffic in the original section of the charging zone has not come to pass. This was expected because with 78,000 households in the new part of the zone being eligible for a 90% discount on the daily charge it was thought some people would decide to drive instead of taking public transport. Presumably, parking charges in central London have acted as enough of a deterrent to using the car.

X-wave CCTV cameras being used to enforce charges

There are two types of analogue cameras within the central congestion charging zone: colour and monochrome. The former are used to give an image of the vehicle in the context of its surroundings while the latter are used solely to provide images for reading number plates. Both cameras operate via a chip, a charged couple device (CCD) and X-wave technology which enables the cameras to see far better in limited light conditions. Initial Electronic Security Systems (IESS) supplied the cameras in a deal worth £8m over five years, which also covered installation and maintenance.

There are 400 camera positions throughout the congestion charging zone, of which approx. 180 are on the inner ring road. Up to seven cameras are mounted at each position on eight metre poles to enable them to read number plates in bumper-to-bumper traffic. In addition to this, there are mobile patrols within the zone. TfL quotes a 90% success rate for accurately capturing each and every number plate, a figure that rises as the vehicle passes more camera positions.

Professional support service provider, Capita, secured the contract with TfL until 2009 to implement and manage the scheme, worth £280m over this period. Capita are responsible for processing payments and fines and employ subcontractors including Mastek, based in Mumbai, India, who are responsible for much of the IT infrastructure.

Automatic number plate recognition (ANPR) technology and involvement of Colt and BT

All images are then sent to the ANPR via a telecommunications system designed and supplied by Colt Telecommunications and BT RedCARE Vision. This system is based on dedicated DWDM (dense wave division multiplexing) technology which links the central data hub with each of the network cameras over analogue video circuits. By using this system, multiple wavelengths can be transmitted over a single optical fibre, allowing large amounts of data that are collected to be sent simultaneously to the image processing centre.

ANPR creates a data block for each recognised number plate, showing the time and date that the images were taken. These are then checked against a database to verify payment or eligibility for discounts and exemptions. Around one million images are collected each day, and distilled 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.

New cameras for western extension of the congestion charge zone

As part of the western extension enforcement infrastructure PIPS Technology was awarded a contract in August 2006 to supply ANPR cameras to Siemens, as part of an infrastructure installation contract awarded by TfL. The contract was worth more than $9m to PIPS for the proven Spike+ cameras.

Spike+ is an integrated ANPR camera and processor combining a dual lens camera (colour and infrared) with a compact processor unit capable of operating 24 hours a day in almost any weather conditions. The system is fully web-enabled and has a variety of data communications options including wireless. The Siemens system uses digital technology, not analogue.

Tag and Beacon technology: a cheaper alternative to ANPR

A much cheaper alternative to ANPR is 'Tag and Beacon' technology. Tag and Beacon involves cars having an electronic tag on the windscreen, which emits radio signals when it passes a roadside beacon, automatically paying the congestion charge. From February to August 2006 TfL tested this on a small part of the congestion charge system.

The six-month trial involved 500 buses, vans and council vehicles with tags. It also required the installation of 19 gantries in South London between Southwark Bridge and Tower Bridge. The gantries contained the beacons which detect the tags and also cameras to catch those who failed to pay. Results indicated the technology worked well and TfL hoped to introduce it across central London in 2009, when it renewed the contract for running the congestion charge.

Controversially the cost of running the ANPR system was thought to be many times more than that of a similar sized Tag and Beacon system. Gordon Taylor, Chairman of the West London Residents Association (WLRA) (who is highly critical of the congestion charge) commented that: "The cost of running the camera system (in London) is nearly 50 times that of the tag and beacon system in Singapore, which is dealing with more or less the same number of vehicles."

The ANPR camera system was expected to be out of date by 2009 and would have wasted, according to several politicians such as Hammersmith and Fulham MP Greg Hands and London Assembly Conservative member Angie Bray, more than £166m of London tax payer money. Tag and Beacon's introduction required a complete reinstallation (wiring) of the system.

Another moot fact is the Tag and Beacon system would significantly cut the number of fines levied for non-payment, as payments are carried out automatically - the majority of fines are levied on those who forget to pay. This would mean a reduction in the revenue stream.

Storing the data: PES and WORM drive

A Permanent Evidence Store repository (PES), provided by TOWER Technology, holds the number plate images collected from vehicles that have driven inside the Central London Congestion Charging zone during charging hours. All images that match the information held on the database are discarded. For those who have not paid the charge, images are sent to the Worm drive (Write Once Read Many).

Each image is encrypted and digitally signed at the first point of capture to prevent any modification to the original image. Images of number plates belonging to those who have not paid to register by midnight are then manually checked against DVLA databases for a penalty notice to be issued. The system stores vast amounts of data (up to several terabytes) comprised mainly of number plate images. Of course those who have paid the charge and not entered London for one reason or another are not reimbursed.

New contract for IBM and NCP Services

In October 2007 TfL announced it was awarding a new contract for the management of the Congestion Charge and the new Low Emission Zone schemes to IBM in a consortium partnership with NCP Services. The contract with Capita expired in 2009, when the IBM consortium took over the project. IBM handles the technology and NCP Services takes care of the enforcement of charges.

The contract is initially for five years with an option to extend for a further five years if amenable to both parties. IBM was the lowest bidder for the services and was also able to help TfL in the change over to a Tag and Beacon system (for automatic payments).

London Low Emission Zone scheme (LLEZ) targeting lorries

On 4 February 2008 TfL introduced its new London Low Emission Zone (LLEZ) for lorries entering London. The LLEZ was introduced to reduce the emissions from polluting diesel engines contributing to the poor air quality in the Greater London area.

"The amount of traffic entering central London during charging hours was cut by around 20%. Congestion charging also raises £130m-150m a year in revenue."

The scheme meant that diesel lorries of more than 12t capacity face a daily charge of £200 if they do not meet strict emissions standards. The LLEZ is the largest in the world, operating 24 hours a day, seven days a week, covering an area of 1,577 square kilometres.

The scheme, which has cost TfL around £49m, is implemented by cameras, which check number plates against the DVLA database. The DVLA database has full details of all vehicle emissions statuses and tells TfL which vehicles do not meet emission standards. This allows a fine of £1,000 to be levied to the vehicle's operator if they fail to pay the daily charge, although this is reduced to £500 if paid within two weeks.

The daily charge has been set to be more than just an inconvenience, more as a powerful incentive to upgrade fleets to meet the standards. Foreign lorries already meeting standards have to be registered with TfL or will face an automatic fine.

The scheme has been extended to cover buses, coaches, large vans and minibuses. Emissions standards were also been made more stringent from 3 January 2012. The vehicles must meet Euro IV emission standards.

Ken Livingstone, the former London Mayor, commented that thousands of Londoners suffer ill-health from pollution released by traffic fumes, which necessitated them to launch the London-wide Low Emission Zone. He added that it would improve Londoners' quality of life and clean up London's air, which is currently among the most polluted in Europe. He also added that the zone does not apply to cars or motorcycles, but instead targets the most polluting diesel-engined lorries, coaches and buses, with the positive effects of the zone being felt across the capital.

The information campaign (press, posters, road shows) publicizing the LLEZ and its effects have been ongoing since June 2007. The scheme has also been publicised in Europe for the benefit of foreign operators. The LLEZ does not include the M25 where there are warning signs that can allow a lorry to plan a new route to avoid them. There are detailed maps available, setting out exactly where the zones start and finish.