The congestion charge has cut traffic jams by 40% on London's roads, the first full review of the scheme has found.
Average traffic speeds have risen to 11mph
Mayor Ken Livingstone predicted congestion would be cut by between 20% and 30%, which would have raised at least £130m towards London's public transport.
But the latest findings from Transport for London (TfL) show the £5 daily charge to drive into central London has reduced jams by nearly twice that amount.
Traffic speeds are up by one third, although the average speed is still only 11mph, meaning the average driver is spending 13% less time in his car.
Mr Livingstone said the results meant even the scheme's sceptics would have to recognise its benefits.
He added: "Fewer traffic jams and faster, more-reliable journey times into and within central London are good for business, tourism and Londoners."
The heart of the independent retail sector has been ripped out
David Blagden, fishmonger
But many businesses say they have been affected in some way by the charge, as fewer customers are prepared to drive in.
One of those who is suffering is David Blagden, who runs the fishmongers set up by his father in Marylebone, central London in 1954.
He said: "Since February 17 our turnover is down 20%, simply put it was £10,000 a week, now we are doing £8,000 a week.
"The heart of the independent retail sector has been ripped out."
And the AA Motoring Trust said it believed fewer roadworks and re-phased traffic lights had also had an impact on congestion.
A spokesman said: "If this had been done before congestion charging was brought in, there may have been reduced congestion, without introducing the scheme."
TfL compared the first three months of the charge to the same period last year to compile the figures.
The report also found 2,000 motorists have switched to the Tube at rush hour and 6,000 are taking the bus.
An average of 98,000 motorists and 12,000 fleet vehicles pay the charge every day.