Gisborne District Council is working to provide an alternative road route to allow motorists full access to the East Coast.
State Highway 35 remains closed between Tolaga Bay and Tokomaru Bay due to a large slip at Busby's Hill, just south of Tokomaru Bay.
A geo-technical engineer will be on site on Thursday to assess the unstableness of the hillside.
The district council says clearance of slips on several back country roads is a priority, so residents north of Tokomaru Bay can get to Gisborne.
The detour will add about an extra hour to their journey.