Lincolnshire County Council expects the total programme of works to last for up to six weeks, subject to suitable weather.
As part of the project, Green Man Road, between its A15 junction and the speed limit signs entering Navenby village, will be fully closed.
The diversion route for the 24/7 closure will be via the A15, B1202 Heath Lane, A607 Grantham Road and Green Man Road, and vice versa.
The road closure will be lifted on Wednesday, June 30 and Thursday, July 1 for the major Cereals arable farming event in Boothby Graffoe.
Green Man Road has also seen a major housing development spring up in the last couple of years alongside it as it enters Navenby.
Karen Cassar, Assistant Director – Highways, said: “Not only will we be widening Green Man Road, but we’ll also be taking the opportunity to fully rebuild it as part of this project.
“This will involve removing the current carriageway and replacing it with 8,000 tonnes of tarmac and other road materials, as well as adding an extra one metre to the carriageway for vehicles.
“Once complete, these improvements will make travelling around the area much safer and more comfortable for all road users.”
For up-to-date information about this and other roadworks, visit www.lincolnshire.gov.uk/roadworks.