New Zealand’s Mt Messenger Tunnel reaches completion of upper section

New Zealand’s Te Ara o Te Ata – Mt Messenger Bypass project reached a major milestone this week as crews successfully broke through the 235-metre tunnel, one of the key components of the future State Highway 3 route in North Taranaki. The breakthrough, achieved by a 110-tonne roadheader known as Hinetūparimaunga, symbolises years of planning and perseverance. The tunnel forms part of the 6km bypass designed to replace the existing steep and winding route over Mt Messenger, significantly improving safety and travel reliability.

The Mt Messenger tunnel is the first permanently lined shotcrete road tunnel in New Zealand, marking a shift in local tunnelling practice. The sprayed concrete lining applied during construction will serve as the permanent structure, requiring precise material control and workmanship. The project was celebrated with a traditional karakia led by Ngāti Tama, the local Māori iwi partnering in the project. The ceremony highlighted the iwi’s role in shaping the bypass, following an agreement that included environmental stewardship and land exchange provisions to preserve local heritage and ecosystems.

Excavation of the tunnel’s lower 2.5m section is now underway, with full completion expected by February 2026. Construction of a 125-metre bridge, supported by a temporary staging structure, is also progressing. Once finished, the bypass will deliver a safer and more efficient route linking Taranaki to the wider North Island, reducing travel times and improving resilience against weather disruptions.