Work to repair the cracking in State Highway 5 near Tumunui south of Rotorua will start from Monday.
The repairs are expected to take approximately six weeks and will involve digging out the damaged section, constructing new embankments, and reinstating the road.
NZ Transport Agency contractors will be digging out and replacing a 12 metre wide, four metre deep, stretch of the highway which has been damaged by a natural process called tunnel erosion.
Tunnel erosion starts at depth and gradually migrates to the surface in this case causing cracks to appear in the road.
During construction the road will be one lane only and will have stop/go traffic control in place during the day and traffic lights at night.
To reduce strain on the road overweight vehicles (those with loads beyond standard legal limits) excluding 50MAX or HPMV will not be permitted to drive through the area from Monday August 15 for approximately six weeks.