The £100,000 resurfacing project of Cross Keys Bridge at Sutton Bridge will start on Monday and is due to last four weeks.
Delays are expected around the works with three way traffic lights to be installed on the bridge.
The alternative is a sign-posted 32-mile diversion along the A47 and A1101.
Karen Cassar, Lincolnshire County Council’s assistant director highways, said: “The bridge has suffered a lot of wear and tear since it was last resurfaced around 10 years ago and it’s vital we repair it.
“Unfortunately, this isn’t as straightforward as resurfacing a regular road – swing bridges require specialist techniques and materials.
“We expect the repairs to take around four weeks to complete, but this will depend on the weather.
“This is an important route for the county, and there will inevitably be some disruption, so we would ask motorists to be patient, to leave additional time for their journeys and use alternative routes where possible.”
The bridge will remain operational for marine traffic throughout the project.
