The £3.37 million project to upgrade Scott Bridge, on Newton Road in Great Barr, will begin on Monday and last 43 weeks.
The dual carriageway A4041, which connects the Black Country to Sutton Coldfield, will have lane closures for around four weeks at the beginning of the work while crossover points are installed.
One half of the bridge will then be closed for 10 weeks at a time while the structure is upgraded and the road will not be back fully open until around March 22.
Sandwell Council said warning signs would be installed on key routes in a bid to reduce traffic and keep disruption to a minimum during the contraflow system.
A compound for will also be created for staff working on the bridge, which takes Newton Road over the Tame Valley Canal.
The traffic calming measures are scheduled to start mid-May and the lane crossovers mid-August.
After the initial four-week closure, key changes include:
Single-lane closure in the direction of Scott Arms (eastbound) – for around 10 weeks from mid-June
Contraflow with westbound carriageway closed – for around 10 weeks from mid-August
Contraflow with eastbound carriageway closed – for around 10 weeks from late-October
Single-lane closure in the direction of Scott Arms (eastbound) – for around six weeks from January 2022
Lane closures in both directions to reinstate central reservation – for around three weeks from early-March 2022 until the project is completed
The bridge's deck and structure are due to be repaired and waterproofed, the road will be resurfaced and painted and the bridge parapets will be upgraded.
The need for the work was identified during routine bridge inspections and has not had major repairs on it until around 30 years ago.
The project is being carried out by R&C Williams Ltd. Letters detailing the works have been sent to local residents.
Sandwell Council’s deputy leader Councillor Maria Crompton, said: “This is a major piece of work to make vital repairs to the bridge and we apologise for any inconvenience it may cause to residents and drivers.”
Sandwell Council’s cabinet member for sustainable transport, Councillor Jackie Taylor, added: “We will be working closely with the contractor to monitor the work and keep any disruption to an absolute minimum.
“I am delighted that this major work is finally taking place. Our bridges need to be safe as well as our roads. I understand that there will be some frustration during this time.
“I would encourage you all to give yourselves extra time for travelling or consider different modes of transport for your journey.”
The work is being funded by £2.99m from the Department for Transport Bridges Challenge Fund and £371,000 from Sandwell Council.