Park-and-ride sites keep 500 motorists off roads every day
The number of people using the facilities at Ingliston and Hermiston has quadrupled since September, preventing more than 50,000 car trips since opening.
Around 170 motorists are parking at the Hermiston site every day during the week, with more than 300 more people using the Ingliston park-and-ride.
When the facilities opened in September, only around 100 people were using the park-and-rides on a regular basis.
However, operators have been left disappointed that weekend shoppers continue to shun the 2 million project, with as few as half-a-dozen motorists using the park-and-rides on Sundays.
Some buses are heading into the city with nobody on board at the weekends, apart from when large sporting events are held.
Opposition politicians said the Capital was still lagging far behind English towns such as York and Oxford, where park-and-rides have been in place for more than a decade.
But the council insisted it was making up for lost time and said the two park-and-rides were growing at a faster rate than had ever been achieved in another city.
Councillor Andrew Burns, the city's transport leader, said: "These figures are fantastic. In just six months Ingliston and Hermiston have become the fastest growing park-and-ride sites in the country.
"A recent survey, by Lothian Buses, showed that 79 per cent of those using the sites are making their way to work."
The Hermiston park-and-ride has space for 450 cars, while the more popular site at Ingliston can hold 575 vehicles.
The council has already said it will need to consider expanding the facilities as they continue to grow.
By mid-March, just over 50,000 cars had parked at the two sites, with a weekly average of more than 2500 users.
The busiest week came in February, when Scotland played England in the rugby Six Nations tournament at Murrayfield.
There were 242 people parking at Ingliston and 172 at Hermiston on the day of the game.
Iain Coupar, Lothian Buses' marketing director, said: "We are greatly encouraged by the success of the Ingliston and Hermiston park-and-ride sites.
"Their up-take in the first six months has been overwhelming. The sites have proved that there is a need and desire for bus-based park-and-ride facilities around Edinburgh."
A park-and-ride scheme based in Fife at Ferry Toll was used as the template for the council's project. It suffered a very slow start after opening in 2000, but has since expanded rapidly to cope with demand.
Gavin Booth, the chairman of Bus Users UK, said: "Normally, park-and-rides take a long time to build up. I can see Ingliston and Hermiston expanding in the near future, and anything that takes people out of cars and on to public transport is a good thing."
Councillor Allan Jackson, the Tory's transport spokesman, said: "These two park-and-rides are probably the fastest growing in the UK, but that's only because we are so far behind.
"We have been shouting for this for many years, but this council and its predecessors dragged their feet. I am delighted to see the park-and-rides are now working well and helping to relieve congestion in the city."