The works are scheduled to begin on Monday 12 October and continue for approximately five weeks, until Friday 13 November.
The works will involve concrete testing and repairs to the bridge, as well as the installation of new steel ducts at the parapet.
To ensure the safety of road users and the workforce, a single-lane closure will be in place 24 hours a day for the entire duration of the works, with two-way temporary traffic lights in operation to maintain the flow of traffic through the site.
Richard Cook, BEAR Scotland’s North West Bridges Manager, said: “These maintenance and investigation works are essential to ensuring the structural integrity and long-term durability of the bridge, while also providing information that will support its future maintenance.
“Our aim is to complete the works as safely and efficiently as possible and we’d like to thank road users and the local community for their patience during this time.”
Real-time journey information is available from Traffic Scotland at www.traffic.gov.scot and on X @trafficscotland.