The Kawarau Gorge Road between Cromwell and Arrowtown has reopened.
A rockfall left a large rock hanging over the road on Saturday, the Transport Agency worked to clear the area and the road reopened at 6pm on Sunday.
The agency's Central Otago manager, John Jarvis, is warning motorists to add extra time to their journey plans, as work is still required to clean up residual rocks in the area.
Mr Jarvis says motorists should take particular care to look out for rocks from any other falls.
There are a number of slips and washouts on other roads in the lower South Island.
State Highway 1 is closed between Clinton and Gore after a washout, and caution is needed on SH1 south of Waikouaiti after a slip. State Highway 85 at Dunback has been washed out, and although vehicles can still get through, extreme care is required.