Repair work is set to begin on a stretch of road near Cairnryan - three years after it was affected by landslips due to winter storms.
Both sides of the A77 at Marchburn near the South Ayrshire and Dumfries and Galloway border were affected in 2014.
Traffic controls have been in place ever since despite some temporary repairs being carried out in 2015.
Now full reinstatement work is to start in November which is expected to be completed early next year.
The road will be shut completely between 20:00 on 3 November until 06:00 on 6 November to put support piles in place.
Scotland TranServ said it was currently in discussion with a number of utilities and other authorities in regard to the planning and management of the work.
It said that after the weekend closure the existing traffic lights would be reinstated to allow contractors to work safely.
"This is a large, complex project that we expect will take a number of months to complete," it added.
"Our contractors therefore forecast that the traffic lights will be lifted, and the road fully reinstated early in 2018."