Contractors are using explosives to loosen rock on the Nevis Bluff above State Highway 6, between Cromwell and Queenstown.
The blasting work is part of the NZ Transport Agency's regular safety routine.
Blasting the Nevis Bluff, 120 metres above the highway, is no quick task. The work done by Fulton Hogan contractors took an hour to complete, holding up traffic for safety reasons.
The work is part an on-going safety and monitoring routine by NZTA which also involves abseil inspection and rock scaling to remove loose debris and unstable rock.
NZTA is advising motorists to allow an extra 10 minutes for travel between Cromwell and Queenstown.
The rock stabilisation work started over two weeks ago and continues until the end of the month.
