SH2 Remutaka Hill underslip site Photo: NZTA Waka Kotahi
Remutaka Hill road, which links Wairarapa and Wellington, will close at night for about up to two months for urgent work to repair a major slip.
New Zealand Transport Agency (NZTA) said the underslip on the Wairarapa side of the hill that happened earlier this month required urgent repairs and may mean up to nine weeks of night closures, starting in October.
NZTA regional manager Mark Owen said the slip was severe.
"We need to stabilise the slip and build a retaining wall to protect the road. This will need a substantial construction effort," he said.
Photo: NZTA Waka Kotahi
Drivers should anticipate travel delays with 24/7 stop go signs in place while repairs were underway.
About 7000 vehicles cross the State Highway 2 road linking Wellington and Wairarapa daily, said Owen.
"The Remutaka Hill is a critical transport link, which we can't afford to have compromised.
"It is essential we fix this underslip before the end of the year and the summer holidays, and before KiwiRail carries out work on the Wairarapa railway line, which will see bus replacement services using the Remutaka Hill route."
The night closures will begin on 7 October with the road closed between 9pm and 4am, Sunday to Thursday, it would remain open to one lane on Friday and Saturday nights.
Escorted crossings could be booked on NZTA's website, but there would only be one crossing in each direction at midnight.
"This is fewer than we do during our normal planned maintenance closures. However, we need to keep the site shutdowns to an absolute minimum so we can finish the work as quickly as possible."