Motorists on the A90 face a months-long lane closure after the flyover from St Madoes to Glencarse was damaged in a crash.
A one-lane traffic light system will be introduced on the flyover from Wednesday evening when it reopens.
The A90 southbound underneath will also be restricted to one lane.
Amey – who operate the road on behalf of Traffic Scotland – say this will continue until repairs are complete.
It comes after a digger being carried on the back of a truck smashed into the bridge on Tuesday afternoon.
The A90 was closed southbound for much of the afternoon following the incident, while the flyover has remained closed for most of the day on Tuesday.
One man has been reported to prosecutors following the collision.
Amey has not said when the repairs will be complete, however motorists have been told to expect a “similar timescale” to the 12-month project carried out after a bridge strike in October 2019.
Plans for a long-term solution to prevent future bridge strikes are also being looked into.
A90 repairs may take ‘a considerable amount of time to complete’
The announcement comes after engineers spent eight hours assessing the bridge, finding significant damage to one of the steel elements and the concrete deck slab above.
They also discovered that the bridge’s steel load bearing element has also been badly deformed and will need to be repaired
Operating company representative for the North East NMC, Tom Wallace, said: “Our engineers have carried out a detailed inspection of the structure and have identified extensive damage to critical parts of the overbridge.
“Road users and local communities should be assured that we will do everything we can to repair the bridge as quickly and safely as possible to allow it to be fully reopened.
“However, this is a complex operation and, as previous essential repair work on the bridge has shown, can often take a considerable amount of time to complete.
“Amey would like to thank all road users and the local community for their patience in advance.
“Motorists are encouraged to plan their journeys in advance by checking the Traffic Scotland website for up to date travel information.”
Councillor urges engineering form to work quickly on repairs
Councillor Angus Forbes has urged Amey to undertake the work quickly.
He said: “I am delighted that the bridge that links St Madoes to Glencarse will reopen today under traffic light control, no one wants to return to the same situation we had last time where these communities with so much in common were split for almost a year.
“However, the suggestion that the works will take the same length of time as the previous incident is concerning to me because that was a huge inconvenience for residents, not to mention local businesses that really suffered.
“I would urge Amey to expedite those repairs as quickly as they can.”
The councillor also plans to meet with Amey to discuss how future bridge strikes could be avoided.
He added: “One example might be a height sensor in advance of the bridge to warn any over-height vehicles to leave at the next junction and avoid the bridge.
“I am sure that would be a low-cost solution.”
Conversation