Blasting work will start immediately to stabilise part of the slip face in Waioeka Gorge.
This could cause delays of up to 30 minutes for drivers using State Highway 2 between Bay of Plenty and Gisborne but the temporary road will remain open.
The New Zealand Transport Agency (NZTA) said a geological site inspection indicated the slip face was "relatively stable", despite a fractured area on the Opotiki side of the slope moving 60mm when measured on Monday.
Bay of Plenty state highways manager Brett Gliddon said work would commence immediately to stabilise this and other parts of the slope.
The work included minor blasting and excavation and is expected to take about four weeks.