TRANSPORT

2nd Terrace Tunnel

NZ Transport Agency Waka Kotahi · Wellington

A new ~0.5km southbound tunnel duplicating the existing Terrace Tunnel; the existing tunnel (opened 1978) is retrofitted to carry 2 lanes northbound with fire and life-safety upgrades. Not separately costed: see the combined $3.8B package entry for the disclosed figure.

Mixed signals Data: Medium

Delivery Confidence Score, 0 to 100, higher is better: a ranking of how strong this project's delivery signals are, not a probability. It blends eight factors, including the election risk and policy alignment shown below.

Breakdown▾

Data current as at 13 Jun 2026, when the pipeline was last checked against its source.

Key facts

Region: Wellington
Part of: Wellington Transport Package (SH1 Improvements)
Sector: Transport
Status: Planning
Estimated value: Value TBC
Indicative completion: TBC
Funding status: Part Funded
Lead organisation: NZ Transport Agency Waka Kotahi
Election risk: Medium

Election risk assessment

One of three components of the $3.8B SH1 Wellington Improvements package (see 'Wellington Transport Package'); Labour and the Greens have said they would reinstate a mass-transit-focused programme instead of the roading-led replacement for LGWM.

Government priority alignment

MEDIUM: Part of the roads-focused replacement for the cancelled, PT-heavy LGWM; aligns with the current transport policy statement, though scope remains contested.

Chronology

2024NZTA Board endorses the preferred option (Oct): a duplicate Terrace Tunnel
2025Investment case endorsed (Aug); community engagement on the design runs Nov-Dec
2026Early geotechnical and hydrogeological investigations complete; fast-track consent application lodged (Aug 2026)

Source

SH1 Wellington Improvements (NZTA) ↗

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