The contract notice puts the estimated value at between £58m and £72m.
The length of road to be upgraded is 3.8km. The works include grade separated junctions at the Fairthorne and Longfield Road Junctions at the south end of the scheme.
Contractors must submit expressions of interest by 29 August. Five firms will then be invited to bid in October.
The project is expected to take 30 months to complete, from the award of the contract.
For more details, see our Contract Leads section.
The Highways Agency has produced this fly-through of the scheme: