Plans for a new metro system that could link Cambridge to St Neots and Huntingdon is expected to cost £4billion, according to a new report.
A strategic outline businesses case compiled by consultants Steer said the Cambridgeshire Autonomous Metro (CAM) could improve the transport system in the county "significantly" and there was a "compelling case" for the idea.
The report also said that up to 100,000 jobs and 60,000 new homes could result from the metro system, which would connect Huntingdon, Alconbury, St Ives and St Neots to Cambridge.
The Cambridgeshire and Peterborough Combined Authority, which commissioned the report, has said the scheme would include a 12km of 'twin bore' tunnelling under Cambridge and the two underground stations, one located in the city centre and one located at the existing Cambridge station.
The combined authority also said in the report that the scheme would extend to about 142km.
The CAM would operate on a 'turn up and go' service, according to the report, where users would arrive at terminals with the expectation of a 'service within minutes'.
A blend of funding sources from the Government and local contributions is expected to form the basis of a future funding strategy, though no complete package has yet been decided.
There is a precedent for schemes being funded in this way, including Crossrail and the Northern Line extension in London.
Mayor James Palmer said: "This is a hugely significant step forward in what will be a transformational project for Cambridgeshire and Peterborough and one of the most pioneering transport infrastructure projects seen in the UK.
"What is also hugely important is that this study shows we have a scheme that is deliverable and that every pound invested in the CAM will repay itself two to four-times over."
The report also stated that the vehicles would be able to travel at a maximum speed of 55mph.
Councillor Lewis Herbert, chairman of the Greater Cambridge Partnership, which is supporting the CAM project alongside the mayor, said: "This metro, combined with other transport schemes like better rail and the proposed Cambridge South station, will transform public transport, not just in Cambridge but right out across the whole of southern Cambridgeshire into our neighbouring counties."
If successful, construction could start as early as 2021.