The £507m contract will see Skanska design and build the A428 Black Cat to Caxton Gibbet improvements scheme.
The project replaces the only remaining section of single carriageway between Milton Keynes and Cambridge, tackling one of the region’s most notorious congestion hotspots.
It will see a new 10-mile dual carriageway built linking the A1 Black Cat roundabout in Bedfordshire to the A428 Caxton Gibbet roundabout in Cambridgeshire.
The new road will also be an important link between the M1 and the M11, connecting Milton Keynes, Cambridge, Bedford and St Neots.
Around 25,000 vehicles travel on the A428 between Cambridge Road and Caxton Gibbet every day.
With considerable local housing and job growth expected, this number is likely to increase to around 33,000 vehicles by 2040.
The project is being led by Skanska, working in close collaboration with design partner Mott McDonald and Highways England. Skanska won the work through the Highways England Regional Delivery Partnership (RDP) framework, for which it is a Delivery Integration Partner for the East of England and Midlands regions.
Lee Galloway, Highways England A428 Black Cat to Caxton Gibbet Improvements Interim Project Director, said: "The A428 Black Cat to Caxton Gibbet improvements scheme will transform one of the busiest road links in the East of England, helping to save drivers who live, work and travel in and around Bedfordshire and Cambridge an hour-and-a-half on their journeys every week.
"We’re extremely excited to be working alongside Skanska as we move through the design stages of this project and onto starting main construction."
Jonathan Willcock, Managing Director of Skanska’s Infrastructure business, added: "We’re delighted to have agreed this contract with Highways England which will deliver lasting benefits to the region. It builds on our long-standing and trusted relationship with Highways England, through which we have delivered many successful projects.
"We know the area well and will work closely with communities along the route to help keep the roads running during the works while providing training and job opportunities for local people – helping to deliver a lasting legacy."
Highways England submitted its application for a Development Consent Order to the government’s independent planning authority, the Planning Inspectorate, on 26 February 2021.
The Planning Inspectorate has 28 days to decide whether to accept the application for consideration.
The pre-examination period and examination period then follow with a decision expected in 2022.