The introduction of the congestion charge was met with mixed reactions. Almost four years on, and with the western extension in site, the debate as to its success to date continues.
So how has all the money been spent? And do we really have a cleaner, greener London as a result?
According to a published report from Transport For London, congestion levels in the zone are on average 26% lower inside the zone than in 2002 before the scheme was introduced.
The national environmental transport body, Transport 2000, claim that during charging hours 65,000 fewer car movements per day are being made into or through the zone.
Michele Dix, director of congestion charging, has said that, "the key of the congestion charge is to reduce levels of traffic coming into central London which is something we continue to see.
The capital is the only major city in the world to achieve a shift from private car use to public transport, delivered through a combination of congestion charging and expansion of the bus service."
|More London buses, faster moving traffic|
All the money raised from congestion charging, by law, must be re-invested back into London's transport system. Last year, TfL claims £122 million was raised. The plan to put most investment (an estimated £84 million a year) into London's bus services was intended to take pressure off the tube.
Conservative councillor Phil Taylor challenge's TfL's assertion that congestion charging is generating substantial surpluses. He says: "TfL's own statement of accounts show that the cumulative surplus generated from the start of the scheme until the end of the last financial year was only £189.7 million.
"This amount has barely covered the original scheme's set up costs of £161.7 million. Pretty much all of the £677.4 million collected in the first three and a bit years of operation of the scheme has been spent on out of control set up and running costs."
Transport 2000 have estimated 29,000 additional bus passengers are entering the zone on 560 extra bus services in the morning peak period.
The increase in buses on the roads along with the cut of congestion has seen a positive effect on commuting by bus. TFL reports the excess waiting time for buses has been cut by 46% within the zone.
As well as providing more buses, the new greener hybrid fuelled buses have been introduced. There are currently six single decker hybrid buses operating on the 360 route from Elephant and Castle to Kensington.
The buses run on a combination of diesel and electricity, resulting in a 31% drop in carbon dioxide emissions, not to mention a two decibel drop in engine noise.
Plans for a double decker hybrid fleet is also on the cards, with Mayor of London Ken Livingstone revealing the first bus of its kind in the World on 2 November 2006.
The congestion charge has begun to focus on much more than congestion alone and environmental issues are high on the Mayor's agenda.
The latest figures from TFL show that so far there has been a 13% reduction in Nitrogen Oxide and 15% reduction in Particulate Matter vehicle emissions within the zone. Carbon emissions have been reported as being cut by 16%.
Transport 2000 have also reported that the congestion charge has led to an increase in alternative modes of greener transport, such as cycling, up by a third inside the zone.
Some of the charge's policies, however, have come under fire for not prioritising environmental factors enough. Liberal Democrat London Assembly Transport Spokesperson, Geoff Pope, has labeled the "one size fits all congestion charge" as "outdated and flawed".
The £8 charge for the majority of vehicles entering the zone has sparked initiatives from groups such as The Green Party for alternative pricing methods. These include a sliding scale charge depending on individual vehicle's size and emissions and how centrally travel takes place.
For drivers of small vehicles, the Green Party suggest the charge could be cut by up to 75%. Green Party member of the London Assembly and Deputy Mayor, Jenny Jones, accepts that, congestion charging on its own is not enough to curb London's congestion and environmental issues.
A TFL consultation on the introduction of a low emission zone, which would charge greater tolls to drivers causing heaviest pollution, has now begun.
As things are the Mayor's Air Quality Strategy already states his aim to accelerate the uptake of cleaner vehicles and TFL have proposed to raise a £25 million Climate Change fund for clean, green initiatives. Low emission buses are one of the first steps towards meeting these emission reduction targets.
Find out more about the Mayor's Air Quality Strategy in the links in the right-hand column of this page.
Putting money into the buses themselves is not where the buck stops in improving the entire transport system for the public. The investment into safety has increased from £18 million, in 2000, to £42 million.
As well as TFL's work with the police and London boroughs, the increase of new CCTV cameras has gone to assist continued safety on the streets.
Cameras, traffic calming and safety campaigns have led to an over all reduction of those killed or seriously injured by 40% in the last year alone and since the congestion charge was introduced TFL report that personal accidents have gone down between 40% and 70%.
Deputy Mayor and safety ambassador Jenny Jones has said, "What London has successfully shown is that road safety works, especially when you increase the budget and you are very determined to do what is necessary to stop death and injury on our roads."
On 19 February 2007 the congestion charge extended west to cover Chelsea, Kensington and Bayswater.
The extension has met with a degree of criticism. The FPB (Fighting For Private Business) reports that following a public consultation the substantial majority of respondents did not want the zone extended, but Mayor Livingstone considered the consultation "was not representative" and gave the extension the go-ahead.
Fears for small businesses are high on the list of concerns. The FPB conducted a survey of 500 small to medium-sized firms in London in November last year and found that 58% had seen profits drop since the congestion charge was introduced. Meanwhile, a third had thought of relocating, and two thirds reported a drop in footfall of clients and customers.
Where larger businesses are concerned, however, the Commission for Integrated Transport suggests that most managers report differently. They point out that potential benefits flowing from improved transport speeds and reliability should reduce the cost of operating in Central London. This would counter balance to some degree the charge itself.
Transport For London has reported no identifiable effect on businesses starting up or closing down within the zone compared to the rest of London.
It is hoped instead that the extension will benefit the new area by cutting congestion by 15 - 20%. TFL predict there will be 10 - 15% less traffic in the zone during charging times, resulting in journeys into the extended zone being sped up by an average of five minutes.
Do you agree with TfL's findings? Has the congestion charge worked for you? Email us at email@example.com