Waka Kotahi NZ Transport Agency will reopen State Highway 1 over the Brynderwyn Hills to all traffic in both directions from 6am on 1 May.
SH1 over Northland's Brynderwyns has been closed off and on for weeks after several huge Cyclone Gabrielle slips. These slips scuppered a brief opening just before the cyclone, after it had also been similarly shut due to previous slips for some time because of earlier bad weather.
Waka Kotahi's regional manager maintenance and operations Jacqui Hori-Hoult said crews have worked extremely hard over the last two weeks to reinstate access as usual for Northland road-users.
"We've made great progress over the two-week closure, which allowed us to complete major earthworks. We were able to advance our work across all three over slips where we reformed the hillside and removed loose material to make it safer.
"Excavators, in some cases being safely held in place by a winch, have been casting the dirt from the top down, with trucks then picking up the material and carrying it from site."
A substantial amount of material had been removed and drainage had also been installed to help to future proof stormwater resilience, she said.
"Over the next few days, we will continue to remove material, finalise drainage and complete concrete stabilisation over an under slip. Along with this work, we will complete pavement repairs on other sections of the road, hydroseeding (planting) over slip areas and general maintenance."
Once the road re-opened, crews would still be working on the highway, removing material from the southern slip sites.
"Traffic management along with a temporary speed limit will still be in place," Hori-Hoult said.
Waka Kotahi recognised it was a key connection to and from Northland for both people and freight, so it was "a massive feat" for it to be fully functional.
"While the road will be open, we'll be closely monitoring it along with the weather. We will not hesitate to close the road if it becomes unsafe."