The proposed full closure was floated as being from Waitangi Day to Easter.
However, the country’s transport agency announced on Tuesday that the road will be closed from February 26 until March 27. SH1 will then reopen for six days over the Easter period before closing again on April 3.
NZTA said in a statement that in total, the closure is expected to be about nine weeks.
Northland Inc chief executive Paul Linton said the timing of the closure was a complex issue but restoration works are crucial to the region’s economy.
“Northland cannot afford another unplanned closure of the Brynderwyns as we experienced in early 2023,” Linton said.
AA Northland District Council chairwoman Tracey Rissetto said while inconvenient, the works will extend the life of the Brynderwyn Hills road which is an essential link for the region.
However, AA believed an alternative route between Northland and Auckland is needed urgently as the aging section of SH1 leaves Northland vulnerable to being cut off from the rest of the country.
Steve Mutton, NZTA’s director regional relationships, said feedback around timings of the closure from stakeholders and the community had helped inform their decision.
He said 200 people had attended one of two online webinars, and 2600 people provided feedback online. NZTA had also heard freight and tourism industry input.
“People have agreed with us that getting the road fixed for the medium term is critical and needs to be done as soon as possible,” Mutton said.
“Ultimately, we have come up with a hybrid option that caters as much as we can to freight, tourism, and the community in general.”
Mutton said the option provides NZTA with more time to prepare for the closure and to work with the Northland Transport Alliance to make sure the local detour routes are ready.
Previous closures wreaked havoc on local roads used as detours, including the route via Mangawhai and Waipū for motorists, and the routes heavy vehicles were directed to via SH12 and SH14.
Mutton said crews were already working to prepare SH12 and SH14.
Many trucks took the shorter Mangawhai route, resulting in truck and trailer units getting stuck and blocking the road between Langs Beach and Mangawhai. That resulted in Civil Defence issuing a ban.
NZTA and the Northland Transport Alliance were finalising the details of local detour routes and ensuring they are as high quality as possible, Mutton said.
A detour campaign will begin in February to remind people that although SH1 Brynderwyn Hills is closed, Northland is still open via a number of alternative routes, NZTA said.