Roadworks expected to last nine weeks are due to get under way later his month on the A90 near Stonehaven.
A major maintenance programme at Cowie Bridge is scheduled to begin on Saturday, August 10.
The project will see £750,000 of improvements carried out and motorists are being warned to expect delays.
Following work completed earlier this year, the project will involve re-waterproofing of the whole bridge deck, carrying out concrete repairs, kerb upgrades, replacement of bridge expansion joints, upgrade the central reserve safety barrier as well as resurfacing of both carriageways on the bridge deck.
Major improvements had been scheduled to take place last year but due to the final stages of the construction of the AWPR, the work was postponed to minimise any inconvenience to road users.
The Cowie Bridge deck and southbound carriageway have been prone to potholes and other road defects in recent years, with some deterioration worsening during adverse weather conditions.
Although temporary repairs have been carried out to the surface, the investment from Transport Scotland will allow teams to complete a full surfacing repair.
A contraflow system will be in operation from Saturday, August 10, and will remain throughout the project.
Work will start on the northbound carriageway meaning two-way, single-lane traffic will be in operation on the southbound carriageway.
It will then switch around mid-September to the opposite side with traffic diverted via the northbound carriageway for the remainder of the project.
The average journey time through the roadworks is expected to increase by around 20 minutes at peak times during the day, but could be longer depending on traffic volumes.
Andy Thompson, BEAR Scotland’s North East representative, said: “This project of road improvements, worth over £750,000, will allow our teams to carry out full repairs to the bridge deck on the A90 at Cowie, creating a safer journey for motorists.
“We’ve planned these works to be carried out under a contraflow system to keep everyone safe during the project.
“Our teams will do all they can to carry out the work as quickly and safely as possible.
“We’re liaising with all relevant stakeholders to keep them fully informed of the project and will take all feedback on board.”
Drivers are being advised to plan journeys in advance.