Government looking into possibility of 'long tunnel' for SH1 Wellington congestion fix

A "long tunnel" is being considered as an alternative approach to fix the heavily congested State Highway 1 in Wellington.

The alternative approach is twin two-lane long tunnels, four kilometres in length, from north of the Terrace Tunnel to Wellington Road - which could cut travel times by up to 15 minutes, the Government said.

State Highway 1 (SH1) connects the hospital and airport with Wellington's city centre and the wider region. 

However, at peak times, the highway is heavily congested and improving SH1 has consistently been part of Wellington's transport strategies. The strategy has typically included four projects: a duplicate Terrace Tunnel, improvements through Te Aro, grade separation at the Basin Reserve and duplicating the Mt Victoria Tunnel.

Now, the Government wants a new option to be considered.

Transport Minister Simeon Brown announced on Monday morning, the Government has asked NZ Transport Agency (NZTA) to consider and provide advice on a "long tunnel" option from north of the Terrace Tunnel to Wellington Road. 

"Boosting economic growth and productivity is a key part of the Government's plan to rebuild the economy. The Long Tunnel option aligns strongly with priorities in the Government Policy Statement on Land Transport (GPS), including a reduction in travel times, greater resilience for the SH1 corridor, and improved safety for road users, pedestrians, and cyclists," Brown said.

He said the option has the potential to deliver up to 15 minutes of travel time savings between the region and Wellington airport, compared to around two to three minutes for the current parallel or diagonal tunnel proposals at Mt Victoria and the Basin.

Brown added the option could be built with less disruption to the city centre and less impact on public and private properties required for other options.

"I look forward to receiving advice from NZTA on the technical feasibility, cost, and funding and financing options for this proposal as NZTA works on delivering the Government's priority of a second Mt Victoria Tunnel in Wellington," he said.

The existing tunnels would be repurposed to provide vital functions in the local transport network to connect the city centre with the highway and outer suburbs.