Project introduction

Te Aranui o Te Rangihaeata – Transmission Gully motorway forms part of SH1. It provides important regional resilience and a safe, modern, reliable route to and from Wellington. The motorway has been open to the public since March 2022 however, some construction related works are yet to be completed.

  • Estimated project cost

    $1.25 billion
  • Project type

    Infrastructure upgrade
  • Project status

    Construction

About Te Aranui o Te Rangihaeata – Transmission Gully

Transmission Gully is part of State Highway 1, and provides important regional resilience and a safe, modern, reliable route to and from Te Upoko o te Ika a Maui – Wellington.

It is one of the largest transport infrastructure projects in New Zealand and was the first motorway to be constructed on behalf of the Government under a Public Private Partnership (PPP) contract. The Government’s PPP contract is with Wellington Gateway Partnership.

Public Private Partnership

Wellington Northern Corridor

  • Benefits
    • 27 kilometre-long motorway with central median barriers, two lanes in each direction and additional crawler lanes on the steeper sections.

    • Better resilience to landslides, floods and damage to the motorway from a major storm or earthquake, plus quicker reinstatement than State Highway 59 (old SH1) in the event of a major earthquake.

    • Improved average peak travel times (estimated at around 10 minutes per vehicle for Kāpiti to/from Wellington, 15 minutes Kāpiti to/from the Hutt Valley and five to seven minutes quicker from Porirua to/from the Hutt Valley).

    • Improved access from State Highway 1 to Porirua and the Hutt Valley, with shorter and more efficient freight movements to and from Seaview/Gracefield, Wingate and the Wairarapa.

    • Important arterial connections for residential and light commercial areas in eastern Porirua to the State Highway network through two new link roads.

    • An alternative strategic link for the Wellington region, which has improved regional road network security.

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