Cambridge A10 £500m upgrade plans suggested
A congestion hot-spot could become a dual carriageway under new £500m proposals aimed at tackling jams.
The A10 north of Cambridge links the city with Ely and it can take the 18,000 vehicles that use it each day 45 minutes to travel the 16 miles (25km).
The Greater Cambridge Partnership commissioned a report into a major upgrade with options including dualling, and a new park and ride site.
Further discussions will be followed by a public consultation into the plans.
The A10 North Transport Study was commissioned by the partnership and carried out by Cambridgeshire County Council and consultants Mott McDonald.
Its report recommends a number of possible solutions including dualling all or part of the route, relocating Waterbeach railway station, building a new park and ride site and creating a segregated public transport route between Waterbeach and Cambridge with new cycling and walking facilities.
The current road was "blighted by significant levels of traffic", the mayor of Cambridgeshire and Peterborough, James Palmer said.
"It's hard to think of a road in Cambridgeshire and Peterborough that is more in need of investment than the A10," he added.
Without improvements, the route is likely to become more congested as thousands of new homes are planned on the former site of Waterbeach barracks - three miles north of Cambridge.
Lewis Herbert, leader of Cambridge City Council and vice chairman of the partnership, said a "modal shift on commutes into the city" was needed, as well as "an answer from government in 2018 on what extra A10 works they will fund".
While no preferred options for the upgrade have yet been put forward, the report will be discussed at various council and combined authority meetings later this month and in February.
A public consultation is expected to begin in the summer.