Watch: Major Mt. Messenger milestone reached with tunnel breakthrough

Tunnel crews on the Mount Messenger Bypass (Te Ara o Te Ata) have broken through the top section of the 235-metre tunnel, marking a key milestone for the project. New Zealand Transport Agency Waka Kotahi describes it as a visible sign of progress toward a safer and more reliable route.

NZTA’s Regional Infrastructure Delivery Manager, Rob Partridge, said the achievement comes after months of work on the southern section and follows recent disruptions on the existing route, where an underslip caused delays for more than three months.

He called the breakthrough “a proud moment” and a major step toward replacing the steep, narrow and winding stretch over Mt Messenger with a new two-lane highway.

The bypass is being delivered by the Mount Messenger Alliance, which includes Downer, HEB Construction, Tonkin & Taylor and WSP in partnership with mana whenua Ngāti Tama.

The project is split into southern and northern sections. Since southern works began in 2022, crews have completed more than 300,000 cubic metres of earthworks and brought the southernmost kilometre up to road level.

With the 6.5-metre-high upper part of the tunnel now open end-to-end, crews will begin excavating the 2.5-metre lower section, with full tunnel excavation targeted for late February 2026.

Work is also advancing on a 125-metre bridge for the new route, supported by a 110-metre temporary staging bridge while foundations are built.

The full project includes a second, smaller bridge and a comprehensive environmental programme across 3,650 hectares, alongside the tunnel and approximately 6 kilometres of new highway between Uruti and Ahititi.

Completion of the northern section remains dependent on ongoing legal matters relating to the final parcel of land required. Earlier this year, the High Court rejected an appeal by landowners and confirmed key Environment Court decisions, while a separate High Court ruling set aside the “killing” component of a Department of Conservation wildlife authority linked to construction activities.

“We’re excited to continue the momentum and deliver a safer, more resilient and reliable SH3 for Taranaki and beyond,” said Mr Partridge.