The A151 at Pode Hole is set to be closed for around a month from July 26 to finish long-awaited repair works.
Temporary lights have been in place since last November with Anglian Water having been taking on works in the past few weeks.
But Lincolnshire County Council say the road needs to be closed between the Crown Hall Farm and Lake Ross Caravan Park.
A county council spokesman, said: “Road reconstruction works to the A151 Dozens Bank in Spalding, between the Crown Hall Farm and Lake Ross Caravan Park, will start on Monday July 26.
“The total programme of works is expected to last for four weeks, Monday to Friday, subject to suitable weather.
“As part of the project, a 24/7 road closure will be in place for the duration of the works.”
The diversion route will be via A151 to Bourne / A15 to Market Deeping roundabout / A1175 to Cowbit roundabout / A16 to the A16-A151 roundabout / A151 to West Pinchbeck, and vice versa.
Coun Richard Davies, executive member for highways, said: “The section of A151, between West Pinchbeck and Pode Hole is nearing the end of its serviceable life, so we’re taking the opportunity to completely rebuild Dozens Bank.
“This will involve removing the current carriageway and replacing it with 1,600 tonnes of tarmac and stone.
“We’ll be doing everything we can to keep disruption to a minimum, including maintaining access for residents.
“When finished, these improvements will make travelling the A151 much safer and more comfortable for all road users.”
