A £116m guided busway - the longest of its kind in the world - connecting Huntingdon, St Ives and Cambridge has opened to passengers two years later than initially planned.
The busway, which is expected to cater for nearly 3.5 million trips annually, will provide a "reliable, fast and frequent service" between the areas, according to council officials.
It will provide an alternative mode of transport for people wishing to bypass the congestion of the A14, officials said.
Ian Bates, cabinet member for growth and planning, said: "The busway will raise the bar for other public transport schemes in the future and is going to be an asset for Cambridgeshire communities to enjoy."
The new scheme will see bus services provided at least every 10 minutes, seven days a week, between St Ives and Cambridge.
Buses will take passengers to Huntingdon every 20 minutes, while an hourly evening service will operate until midnight.
However, pro-rail organisation Cast.Iron has attacked the new scheme, saying it "will not deliver noticeable transport benefits".
And Cambridge MP Julian Huppert said that government transport policy should be reviewed following a range of controversies during the construction of the busway.
Copyright © Press Association 2011