Motorists travelling between Cromwell and Queenstown should expect a slightly longer journey from next week.
From Monday, NZ Transport Agency contractors will start inspecting and removing loose rock on the Nevis Bluff rock face.
Central Otago maintenance contract manager Mark Stewart said people would need to factor an up to 10 minute delay in their weekday journeys for about three weeks.
The work would run from 8am to 5pm from Monday, May 3 to Friday, May 21.
Temporary, lowered speed limits would be in place for the safety of both the contractors and motorists, he said.
"People stopped in their cars may be able to see abseilers inspecting and removing loose rock on the Nevis Bluff rock face," Mr Stewart said.
"We need to ensure the road below is clear when rocks are being dropped or loosened."
The work is being done by the Aspiring Highways team.
"The Nevis Bluff is a site that we regularly inspect, monitor and stabilise as part of our commitment to provide a safe, accessible highway network," Mr Stewart said.
Autumn and spring were the best times to do such work, as traffic volumes were at their lowest, he said.
Subject to weather conditions, the work is expected to be completed May 21.
