Controversial plans for a guided bus route between Cambridge and Huntingdon have been approved by the government.
Once built, it will be the longest in the world - providing 25km of guideway along the disused St Ives to Cambridge railway line, easing A14 congestion.
The ruling comes following a public inquiry with thousands objecting to the scheme. Campaigners wanted the old railway line reinstated.
There was also concern about the impact on areas such as the Fen Drayton lakes.
Bob Menzies, the County Council's Head of Guided Busway said: "Within ten years of opening we expect the busway to attract 20,000 passengers a day."
Cambridgeshire County Council is pushing for government funding, and hopes work could start next Winter.
Councillor John Reynolds said: "With tens of thousands of new homes being built in the area, we must do something to address growing traffic levels and provide improved transport services first."