The New Zealand Transport Agency (NZTA) Board has approved the next phase of the SH1 Wellington Improvements programme as part of the Roads of National Significance (RoNS) initiative.
The SH1 Wellington Improvements project aims to reduce congestion and stimulate economic growth in Wellington.
The upgrades under the project include constructing a second Mt. Victoria Tunnel, a duplicate Terrace Tunnel, and significant upgrades to the Basin Reserve.
These new additions are expected to cut travel times, improve traffic flow, and enhance reliability for both commuters and freight across Wellington.
New Zealand Transport Minister Simeon Brown highlighted that SH1 faces heavy congestion during peak hours, with anticipated population growth set to further strain the network.
Without these improvements, travel times on SH1 between Ngauranga and Wellington Airport are expected to rise by up to 50% over the next decade.
Brown said: “After consideration of all options by the NZTA Board, I’m confident that the chosen option will significantly reduce congestion and provide more efficient and reliable access as we continue to rebuild the economy.
“The RoNS projects previously built by National are some of New Zealand’s most successful State Highway corridors, reducing congestion and improving safety.
“Moving at pace to build a new generation of RoNS signals our Government’s focus on prioritising investments that deliver real value to commuters and businesses.”
The project’s core components include a new 0.7km Mt. Victoria Tunnel running parallel to the existing tunnel. It also involves grade separation at the Basin Reserve by extending the Arras Tunnel and redirecting SH1 westbound traffic to the northern side, and a 0.5km duplicate Terrace Tunnel.
Commuters on the number one bus from Island Bay to the Railway Station are expected to save nine minutes during morning peak times, while the number two bus from Miramar to the CBD could see an 11-minute reduction.
According to traffic modelling, the new tunnels and upgrades are projected to reduce southbound traffic volumes across the Harbour Quays by 30%. This reduction is expected to ease congestion along easing congestion along key routes throughout Wellington.
SH1 Wellington Improvements will proceed as a single-corridor project, with phased delivery. An investment case is set for presentation to the NZTA Board in mid-2025.
