State Highway 3, south of Mokau, is on track to be re-opened tomorrow afternoon following a major slip on Sunday.
The New Zealand Transport Agency said the road should be opened to one lane by 1pm.
"We have been working today with abseilers to remove the last of the loose rock," NZTA spokeswoman Karen Boyt.
"Our geotechnical engineers have now advised us that the cliff face has stabilised sufficiently to allow contractors safely on site to clear the rocks and debris, and reinstate concrete barriers."
The road would be under stop/go management after reopening and would initially have a speed limit of 30km/h.