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.
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.