The project will deliver a dual carriageway A46 bypass to the west of Newark (the A1 is the to the east), providing two lanes in each direction, between the Farndon and Winthorpe junctions.
Works will also include the construction of a new five-arm roundabout at Winthorpe and traffic lights at Farndon junction to improve traffic flows during peak hours.
A new bridge will be built over the A1 where the two roads cross, to the north of the town, and a flyover installed at Cattle Market.
Total project costs are estimated by National Highways at between £400m and £500m. Skanska’s contract is worth £345m.
The A46 Newark bypass connects the M1 and Leicester to the A1 and central Lincolnshire. It is used by 17,000 motor vehicles a day.
Skanska will begin design works in 2022. Subject to development consent being granted, construction work on site is planned to start in 2025 and the scheme is expected to open for traffic in 2028.