A shortened version of the original A14 upgrade has been approved by ministers.
Transport secretary Justine Greening said the improved section would run from Milton, north-east of Cambridge, to the road’s junctions with the A1.
This is slightly shorter than the original £1.2bn widening scheme from Ellington Fen Ditton, which was abandoned as a Government cost-cutting measure in 2010.
Upgrading the A14 has become a pressing issue in Cambridgeshire because it passes near to the planned 10,000 homes new town at Northstowe, and to the Alconbury enterprise zone, and handles a growing volume of lorry traffic on its full length from Felixstowe to the midlands.
Its lack of capacity was seen as holding back development in one of the UK’s most thriving areas.
Ms Greening said the upgraded section would speed traffic by removing existing access points and junctions.
The upgrade would be paid for from tolls, but that the Government has not decided what distance would be tolled or how this would be levied.
Works planned also include construction of a new road on each side of the A14 north of Cambridge to serve local traffic, widening of the Cambridge Northern Bypass between Milton and Girton and a bypass south of Huntingdon between Trinity Foot and the A1.
Ms Greening also gave the go-ahead for improvements to the Felixstowe to Nuneaton rail freight line and a new park and ride site at Alconbury.
She said: “The A14 is a crucial strategic route for the east of England, vital not only for international road traffic using the port of Felixstowe but everyone who relies on it daily.
“This is why my department has been working hard to generate innovative and imaginative solutions to tackling long term congestion.”
Local enterprise partnership interim chair Mark Reeve said: “The problem of delay and unreliability stemming from the current under capacity of the road is one of the biggest barriers to achieving our growth ambitions.”