Letting more light into the Terrace Tunnel


Light levels in the Terrace Tunnel are going up again. New High Pressure Sodium (HPS) lights were switched on last night, as part of the NZ Transport Agency's $50 million tunnel upgrade. They will operate during the day, along with the new fluorescent lights that were turned on in September.

NZTA Wellington State Highway Manager Rod James says that while the HPS lights will noticeably improve light levels during the day, there is still more to come.

"The new tunnel lighting has been designed to help drivers' eyes quickly adjust to the change in lighting conditions as they enter and exit the tunnel.  Once they are fully operational, the lights will be linked to external light sensors that will automatically brighten or dim the lights based on outside conditions. We are still testing the lights, so for now they will be on a single fixed setting."

Mr James says while lighting is a highly visible element of the upgrade, there is also a lot of other work being done.

"The new lights and jet fans will be obvious to people as they drive through the tunnel.  New coloured wall panels will be installed shortly as a visual feature, and lane control signs will be put in place in the near future.

"What might not be so obvious are some of the other features that are going in: a new overhead fire suppression ('deluge') system, drainage to manage excess water if the system has to be used, a new system in the ceiling to electronically monitor vehicle heights to stop trucks or big loads that might hit the tunnel's new equipment, and new cameras to link in with the NZTA's traffic operations centre to monitor road conditions," he says.

The NZTA has worked closely with Wellington City Council, Greater Wellington Regional Council and the NZ Fire Service regarding the design and construction of the Terrace Tunnel's improvements.

The Terrace Tunnel and Mount Victoria Tunnel upgrades are part of the Wellington Northern Corridor Road of National Significance, aimed at improving safety, supporting economic growth, and easing congestion.