Work to build a new retaining wall opposite Chapel Brow on the A628 at Tintwistle will start next Monday.
Contractors for Highways England will construct the wall in front of an existing dry stone wall, which has significant structural problems and has been regularly monitored to allow the A628 to remain open.
Temporary traffic lights will need to be put in place along Woodhead Road for around 100 metres while work to build the new wall is carried out as one lane will need to be closed to protect highways workers.
Highways England project manager Stephen Wales said: “The old wall has been in place for many years and is in need of urgent repairs. That’s why we need to build a new wall in front of it and fill in the gap with concrete to give it extra stability.
“We realise the A628 is already heavily congested, but it is essential that this work is carried out as quickly as possible. The temporary traffic lights, which will be staffed at all times, will be in place for the first three months of the work to ensure our contractors can carry it out safely. As soon as it is safe to do so, the traffic lights will be removed.
“Once the new retaining wall has been built, it will be clad with stone so it is in keeping with the local area.”