The usual detours will be in place: Paparoa-Oakleigh Rd, Cove Rd route via Mangawhai and Waipu, and SH12 / SH14.

Northland Chamber of Commerce chief executive Leah McKerrow said NZTA had previously consulted with the chamber on the timing of the two closures.

McKerrow said she understood the work "had to happen" when there was less chance of rain, but businesses also needed to have "the least disruption".

"We were very clear we didn't want them to do it too close to Christmas," she said.

"It's frustrating that ... it has to happen again, particularly for our tourism and hospitality trades.

"It feels like they've only just repaired it.

"Let's hope if they get a fine weekend, they can do it as quickly as possible."

NZTA said the resurfacing works were "the final stage" of the SH1 Brynderwyn Hills recovery project.

The work involved applying a full-width asphalt surface, reinstating lane markings and passing lanes, and returning the route to 80km/h.

NZTA Northland system manager Steve Matene said the dates and approach had been "carefully considered" to balance the impact on the community while ensuring road crews could do an efficient, quality job.

Paving in spring meant the team could take advantage of drier warmer conditions, and condensing the work into two, four-day weekends avoided extending the disruption over multiple months, he said.

Matene said he appreciated the road was "a crucial connection for Northland" and road crews would be working 24/7 during the closures.

"If we'd chosen to use stop/go traffic management, the works would have taken 12 to 14 weeks.

"Compare that to a full closure, which allows work to be completed in six to eight days."

The Brynderwyns were fully closed for four months last year following damage from severe weather events in early 2023, resulting in severe underslips and overslips.

The closures cost the region's economy hundreds of millions of dollars.

In April and July smaller slips caused delays as the highway was down to one lane.

During the upcoming closures the detour routes are:

National Road Carriers Northland transport specialist Paula Rogers said truckies were aware of the detours.

"NZTA has communicated to us about it, and we appreciate it's going to be done in a timely manner.

"As long as we can get that early communication to the sector then they can make plans.

"We would rather they do it this way, [two long weekends] than closing it for a couple of weeks."

Northland Inc chief executive Paul Linton said the works were "an important step" in keeping Northland connected.

"Every visitor, every truck, and every trip contributes to Northland's economic pulse.

"With these improvements in place ahead of summer, we're ready to welcome guests, support local industries, and show that Northland is well and truly open for business."

The Brynderwyn Hills closures are part of NZTA's summer maintenance plan which will see "significant upgrades" to Northland's transport network.

NZTA contractors will be renewing 204 lane kms of state highway this 2025-26 season, which runs from September to May.

It's the second year of the largest-ever investment in state highway maintenance for the region, NZTA's Jacqui Hori-Hoult said.

The roadworks include 25 lane kms of major road rebuilds, eight lane kms of asphalt resurfacing and 171 lane kms of chipsealing.

Key locations include:

Most of the work would be undertaken at night or outside peak travel periods to reduce the impact on road users, Hori-Hoult said.