After the A46 in Gloucestershire was damaged in the summer floods of 2007, a survey found major work was needed on a 150m length of the road at Coopers Hill.
Now, 12 months after a further landslip which closed the road, work is due to commence. Soil nailing will begin in December, with all work complete by February. The County Council said progress had been delayed because the slip is next to a high pressure gas main.
Businesses along Hawthorns Road through Drybrook said they were suffering financially and have urged Gloucestershire Highways to speed up the work.
Councillor Vernon Smith, cabinet member for highways, said: "I know how difficult this road closure has been for local people and businesses. This is a huge job and with the added complication of a high pressure gas main, we have to make sure we get it right."
Diversions in place
Gloucestershire Highways said it had investigated the possibility of re-opening one lane with temporary traffic signals while the work is going on.
"Unfortunately, the ground conditions suggest that any loading on the road may impact on the high pressure gas main," said a spokesman. "Public safety has to be the priority, so for now the road must remain closed with the current diversions in place."
The council said it expected to spend about £150,000 on the repair project. The work will involve drilling a grid of reinforced steel bars into the slope and the bedrock below the road for about 100 square metres (1,076 sq ft).
Once this soil nailing is finished, the slope face will be protected with steel mesh to prevent future erosion.
The official diversion route is via the A4136 to Huntley then A40 towards Ross.
