State Highway 1 over the Brynderwyn Hills is set to reopen in just over a week's time - right on time for the Matariki long weekend.
The reopening of Northland's main connection to the rest of the country will end four months of disruption to travellers and businesses, with motorists forced to take detours on local roads since late February.
NZTA Waka Kotahi project director Mark Ware said the road would open to two-way traffic from 11.59pm on Wednesday, 26 June.
The highway closed initially after a series of major slips triggered by Cyclone Gabrielle in early 2023.
Temporary repairs were carried out to get the road open again last year, but major work was needed to ensure it did not fail completely during this winter's rains.
The highway was initially scheduled to reopen on 13 May, but that was delayed after another massive slip in April.
Ware acknowledged the disruption Northlanders had faced since February.
"We have really appreciated your patience, especially while we've worked to clear additional slips. Our crews have worked as fast as possible to reopen this critical link … We know that having this road open and more reliable will be a welcome relief to Northland communities and businesses ahead of the busy Matariki weekend."
Work had focussed on creating a shoulder space on the narrow and windy highway, stabilising the hillside, and moving an initial 180,000 cubic metres of soil, followed by a further 60,000 cubic metres as a result of the slips in late April.
Ware said he was grateful to the more than 900 people who had been involved with the project, and the contractors who had worked day and night, in all conditions, so the road could reopen as quickly as possible.
The work to stabilise slopes both above and below the road would not have been possible without a full closure, he said.
The additional space that had been created next to the existing road meant that if there was any fresh damage in future, crews could carry out repairs without lengthy closures.
Some work would continue for the next two-to-three months, including using the newly created shoulder to improve drainage and install anchors on the hillside below the road.
Fresh asphalt would be laid, but that job would wait until drier weather between October and December.
Ware said NZTA would continue to monitor and pay for repairs, if needed, to the two local detour routes - via Cove Road to the east, and Paparoa-Oakleigh Road to the west - until State Highway 1 reopened over the Brynderwyns.