London Mayor Boris Johnson is considering introducing variable rates for the Congestion Charge zone, depending on what time a driver enters it.
Johnson believes that such a system could be used to ease rush hour traffic, with higher prices during these hours persuading people to travel at other times or by alternative means. A similar system has been successful in Stockholm, Sweden.
The mayor has also instructed Transport for London to set up an accounts billing system to make it easier for drivers to pay for entering the charging zone. This could include either direct debit payments or an electronic chip system that picks up a car's entry into the zone.
A TfL spokesman 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.
'His election manifesto committed to introducing account-based payments to reduce the number of drivers clobbered by fines for failing to pay on the day. And a variation of charges according to the time of day was an option given when consultation took place on removing the western extension.'
Currently drivers entering the congestion charge zone in London at any time between 7am and 6pm on weekdays pay an £8 flat rate on the day of travel, or £10 the day after travel.
The earliest any changes could be introduced is 2010.