It has asked the NZ Transport Agency Waka Kotahi to investigate the cost and feasibility of a pair of two-lane tunnels, which would aim to reduce congestion on State Highway 1 through Wellington.

Transport minister Simeon Brown said the Long Tunnel option had the potential to deliver up to 15-minute 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 Reserve.

He said the proposal aligned with the Government Policy Statement on Land Transport, including a reduction in travel times, greater resilience for the SH1 corridor, and improved safety for road users, pedestrians, and cyclists.