Project introduction

In order to ensure the tunnel continues to operate effectively the NZ Transport Agency completed an extensive upgrade programme in 2012. The work included upgrading the fire fighting, lighting, ventilation and drainage systems, new tunnel control buildings and earthquake safety improvements.

  • Estimated project dates

    Dec 2010–Mar 2012
  • Estimated project cost

  • Project type

    Road maintenance
  • Project status


Project updates

Project information
Project posters, (PDF)
Terrace Tunnel lights up
Media release,
Terrace Tunnel Upgrade entering new phase
Media release,
Terrace Tunnel systems set for upgrade
Media release,


The Terrace Tunnel upgrade is now complete and the regular refurbishment closures have come to an end. The tunnel will now close monthly for scheduled maintenance closures.


The upgraded tunnel delivers a wide range of benefits including improving:

  • Fire fighting and emergency response systems
  • Ventilation
  • Drainage
  • Earthquake safety


Work on the $50 million upgrade began in December 2010-the first major upgrade since the tunnel opened in 1978. The upgrade has included a new deluge system, jet fans, lining, lighting and a new traffic management system outside the tunnel which includes over-height detection. All of this work will greatly improve the tunnel's safety.

Thank you to everyone who's been affected by the Terrace Tunnel closures-from the motorists who've had to go around it to the residents living on the diversion route over the past 15 months. We know that at times the work has caused some inconvenience, and we thank everyone for their patience and understanding while we carried out this extensive upgrade.


The Terrace Tunnel opened in 1978, becoming the second highway tunnel in Wellington.  It is 460 metres long and has three lanes (two north-bound and one southbound).  It is now recognised as the gateway to Wellington with its connection between the State Highway 1 (SH1) motorway and the Inner City Bypass.  In peak traffic more than 1000 cars per hour travel through the tunnel.

For the time, the tunnel systems and components that were installed were appropriate. However, modern equipment, which meets current practise, will improve the operation, environment and safety in the Terrace Tunnel.

Project partners

The Wellington Tunnels Alliance is pleased to be working in close collaboration with Wellington City Council, Greater Wellington Regional Council and the New Zealand Fire Service on the Terrace Tunnel upgrade project.

Terrace Tunnel southern portal prior to upgrade.