A new congestion charge system where people pay more to drive in at peak times is being considered by London Mayor Boris Johnson.
The "intelligent" system would be similar to one currently used in the Swedish capital Stockholm.
Motorists would pay more to come in at peak times, but at less busy periods would pay a reduced fee.
The mayor also wants to set up an automated system to make it easier for drivers to pay the charge.
Currently drivers entering the congestion charge zone between 0700 and 1800 weekdays pay the £8 flat rate on the day of travel, or £10 the day after they travelled.
A spokesperson for the Mayor of London said: "Since taking office the mayor has made it clear he believes the congestion charge makes a valuable contribution to reducing the number of cars in central London.
The mayor has asked TfL to make the changes that could introduce account payments as soon as possible
Mayor of London's spokesman
"But he has also made clear that he will consider ideas that could make the charge more effective and easier to pay for everyone affected by it.
"The mayor has asked TfL to make the changes that could introduce account payments as soon as possible but the earliest they could be introduced effectively is 2010."
The scheme would reduce charge at certain times of the day
The mayor announced proposals for the variable system and an easier way of paying the charges - which could include direct debits - in his election manifesto last year.
"That would get away from the crazy system where you suddenly get clobbered by these fines," the mayor told BBC London 94.9 in January.
Colin Stanbridge, Chief Executive of the London Chamber of Commerce and Industry (LCCI), said: "These changes, if implemented, would make the C-Charge fairer, flexible and more business friendly.
"Our latest research shows that 82% of retailers within the C-Charge zone think that flexible charging would be good for their business."
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