Motorists leaving and entering West Norfolk on the A17 are to face more than four weeks of major delays.
The Cross Keys Bridge, at Sutton Bridge is set to be resurfaced as part of a £100,000 project next month.
Throughout the scheme, work will be carried out 24 hours a day and one lane will remain open, controlled by temporary traffic lights.
A diversion via Wisbech will also be in place. Preparation work will take place for two days only during the week beginning Monday, September 2.
And from Monday, September 23, resurfacing work will take place for four weeks.
Karen Cassar, assistant director for highways at Lincolnshire County Council, said it was vital repairs were carried out to ensure the bridge remained safe for people to use.
“It is over 10 years since the surface of the bridge was last replaced and over that time it has worn down due to the high volumes of cars and HGVs using the route,” she said.
“We now need to put a new surface down to ensure the road can be used safely for years to come.
“The investment is around £100,000 and will ensure the bridge has the latest and best possible skid resistant specialist surface.”
Ms Cassar added: “In preparation for these works, we’ve spoken to local residents, businesses and bus services about the project – and they preferred to have the bridge open to two-way traffic under traffic lights, in addition to a diversion route.
“We realise there will be significant disruption and severe delays in the area while the work is carried out, and would advise people to use the diversion route.
“We’d like to reassure residents that will do all we can to reduce the disruption, and get the work completed as quickly as possible.” The bridge will remain operational for marine traffic.