State Highway 1 at the Brynderwyn Hills will be closed for nine weeks next year to allow for critical repair work.
The Transport Agency has confirmed road between Northland and Auckland will be shut from 26 February until 27 March, but opening for six days over the Easter period, before closing again from the 3 April to complete the work.
Regional relationships director Steve Mutton said NZTA initially proposed two closure windows; one earlier and one later, each with benefits and drawbacks for various groups.
"Ultimately, we have come up with a hybrid option that caters as much as we can to freight, tourism, and the community in general. This option also gives us more time to prepare for the closure and work with Northland Transport Alliance to make sure the local detour routes are ready."
He said the decision struck a balance between the need to keep Northland open over the busy Easter period while also allowing crews to get the work done when the weather was fine, completing it as quickly as possible.
Whangārei Mayor Vince Cocurullo said the repairs were needed before there were any major failures.
"It's good that the Brynderwyn work is being timed to avoid the busiest part of the season, and will make the route much more safe and secure. Our destinations have been hit hard by successive years of Covid and storms, and we needed this kind of commitment from [Waka Kotahi] to get back on track."
All the repairs were only a short to medium-term solution, adding no more than five to seven years of life to the route.
Automobile Association's Northland District Council chairperson Tracey Rissetto said an alternative route was needed urgently.
"A more resilient route is essential to Northland's economy and would have significant benefits for all of New Zealand allowing people and goods to get to where they need to be. Progress on an alternative route to the Brynderwyns has been placed on hold for the past six years. Recent weather events have shown the establishment of a new route must be expedited to make up for the time lost," she said.
Cocurullo, who is also the chairperson of the Northland Mayoral Forum, said during the SH1 closure there will still be four other routes into Northland, including the east route through Mangawhai and Waipu, and the west route going through Maungataroto, Ruawai and Dargaville.
"Both routes include local shops, museums and wonderful Northland coastlines, introducing new spots to stop and enjoy along the way," he said.
"Northland is still the best place on your summer holidays, even if it takes an extra 15-20 minutes to get there."