The bridge, which crosses the railway near Thornliebank station, is being demolished and reconstructed over a 14-month period, from Tuesday 2 April until June 2025.
During this time, vehicles are being diverted via Thornliebank Road, Rouken Glen Road, Fenwick Road, Kilmarnock Road and Nether Auldhouse Road (and vice versa).
First Bus is operating a diversion for the 57 and 57A services throughout the works, with full details available at firstbus.co.uk/greater-glasgow.
This £5.5m programme of work is being delivered by Network Rail and its contractor Story and is part of a wider £140m investment in the East Kilbride Enhancement project.
Engineers will create the required clearance height to allow the new overhead line equipment to run underneath the bridge so electric trains can run on the line, as well as installing a new and improved road surface.
Over the coming months until September, the first phase involves diverting a number of service utilities from the existing structure onto a temporary footbridge that is being installed towards the end of April.
Following completion of the utilities diversion, the road bridge will be demolished, from 27 to 30 September, and then the reconstruction work will begin.
Pedestrian and cyclist access will be maintained, and train services at the station will operate as normal – with the exception being the weekend of the bridge demolition.
Simon Humble, project manager, Network Rail, said: “Thornliebank Road bridge represents the largest civils structure on the East Kilbride Enhancement project and is a significant undertaking.
“Although the first phase is a labour intensive period of diverting a number of utilities from the bridge, including fibre optic, water and gas, it allows a substantial part of the work to be delivered during the day.
“When we start the construction phase later this year, this involves more complex engineering – some of which can only be done overnight when no trains are running, and we will update the community in advance of this.
“While we do appreciate the inconvenience of having to close the bridge, it is the only way we can deliver this part of the project and we would encourage everyone to add in some extra travel time.”
Shops and businesses on Thornliebank Main Street and in the surrounding area are open as usual during the works.
The new bridge has been designed in collaboration with East Renfrewshire Council’s active travel team to include enough space for a segregated cycle lane to be introduced in the future.