Transport for London's (TfL) decision to expand the congestion charge westwards was met with a great deal of opposition - but the extension goes live on 19 February.
Malcolm Murray-Clark said the charge keeps London moving
Here TfL's director of congestion charging Malcolm Murray-Clark tells BBC News why it went ahead with the scheme.
In 2003, TfL introduced congestion charging to the central, most clogged-up, part of the city.
Some said the public transport system would not cope, the economy would suffer or traffic would divert into unsuitable areas.
Four years on it's clear they were wrong.
The scheme has been a huge success and, on Monday 19 February, it will be extended west to cover parts of Westminster and Kensington & Chelsea - some of the most congested areas in the UK.
Traffic in the existing zone has been reduced by some 20% since charging began - preventing the gridlock that would most likely have been a regular feature for the capital.
This has brought many benefits to London, including more reliable journeys, a significant cut in carbon dioxide, and a reduction of up to 15% in the most harmful vehicle emissions within the zone.
Independent research demonstrates road safety has also improved, with up to 70 fewer personal road injuries per year as a direct result of congestion charging.
And more people than ever before are feeling safe enough to cycle on London's roads.
There has been a 72% increase in the number of cyclists on London's major roads since 2000, with around 450,000 cycle journeys a day.
But London still has significant congestion problems. Surveys indicate that of all areas adjacent to the zone, congestion is most intense in the west where there are severe delays throughout the working day.
The congestion charge will expand on 19 February
We estimate traffic levels in the western area will be reduced by 10 to 15% when the zone goes live, reducing congestion in the zone by at least 15%.
Additional buses and other planned public transport improvements have been implemented to meet the new demand from those switching from their cars.
New bus services have created an additional 4,800 passenger spaces, encouraging Londoners to make full use of public transport.
With businesses in the extension area employing around 170,000 people, it's clearly important the scheme works effectively. That's why we've focused on making it more convenient to use.
For example, in summer 2006 TfL introduced a "pay-next-day" facility, enabling people to pay the charge the day after they travel.
Companies with ten or more vehicles can register for fleet accounts which streamline administration and reduces the daily charge to £7.
We are also cutting charging hours so that from 19 February they finish at 6pm to benefit the evening economy.
Congestion charging keeps our city moving.
It has contributed hugely to London's position as the only major city in the world to have achieved a shift from private car use to public transport.