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Is the project on track to be completed on schedule?

The Transmission Gully motorway project remains on schedule for completion in 2020.

What effects has Wellington's unusually wet summer had on construction work?

The construction project timeline has contingency for wet weather. While there has been more wet weather over this summer than anticipated, overall there has been minor impact on the construction progress to date.

What is the Transmission Gully project?

The Transmission Gully project is a project to build a 27 kilometre four-lane (a minimum of two in each direction) motorway from Mackays Crossing to Linden (through Transmission Gully). There will be interchanges connecting the route to State Highway 58 and Kenepuru with a connection to Porirua CBD. In addition, there will be two link roads from the eastern Porirua suburbs of Whitby and Waitangirua to the route. The Porirua City Council is the Road Controlling Authority responsible for these link roads. The project entails extensive protection or relocation of utilities including the complete removal of transmission towers by Transpower from the northern section.

Why build the Transmission Gully motorway?

The Transmission Gully project will provide:

  • A safer road and a four-lane route with central median barrier and additional crawler lanes on the steeper sections.
  • Reduced likelihood of landslides, floods and damage to the motorway from a major storm or earthquake.
  • Quicker reinstatement than the existing State Highway 1 in the event of a major earthquake.
  • Peak period travel time savings estimated at around 10 minutes per vehicle for Kāpiti to/from Wellington, 15 minutes Kāpiti to/from the Hutt Valley, five to seven minutes Porirua to/from the Hutt Valley.
  • Easier 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.

How will the Wellington region benefit?

The Transmission Gully route will:

  • Provide an alternative strategic link for the Wellington region, which will improve regional road network security.
  • Assist in remedying the safety concerns and projected capacity problems on the existing State Highway 1 by providing a safe and reliable route between Mackays Crossing and Linden in an environmentally responsive manner.
  • Assist in enabling wider economic development by providing a cost-optimised route that better provides for the through-movement of freight and people.
  • Assist in the integration of New Zealand's land transport system by enabling the existing State Highway 1 route to be developed into a safe multi-functional alternative to the Transmission Gully motorway.

What has been the background to the Transmission Gully project?

View the chronological timeline of the Transmission Gully project before the Public Private Partnership was signed.

When will the Transmission Gully motorway be open for traffic?

The Transmission Gully motorway is scheduled to be open for traffic in 2020.

What is the final contract price arrived at for the Transmission Gully project?

The net present contract price for the Transmission Gully project is $850 million (2014 net present value) - which is $25 million less than if the project was procured through conventional means.

Will the Transmission Gully motorway be tolled?

The potential for tolling the Transmission Gully motorway to offset some of the cost of the project has previously been signalled. However this is being treated as separate to the PPP project and no decision has yet been made in this regard.