Transmission Gully

Porirua is the centre of one of New Zealand’s largest transport projects in more than a century – Transmission Gully.

This $1.25 billion public-private partnership project involves the construction of a 27 kilometre four-lane highway that will run from Mackays Crossing to Linden through a newly developed Transmission Gully. The project is well underway and is set to be open for traffic in 2021. 

For Porirua the Transmission Gully project is huge!  Within Porirua it involves three interchanges and two new link roads that will connect Mackays Crossing, State Highway 58 (Haywards Hill), eastern Porirua, and Kenepuru. 

Kenepuru Interchange

The Kenepuru Interchange will form an important connection between Transmission Gully and Kenepuru Drive in Porirua and will open when Transmission Gully opens in 2021.

As a part of the interchange there is a new link road that bridges the existing SH1, the North Island main trunk railway and Porirua Stream, connecting the interchange on Transmission Gully with a new roundabout on Kenepuru Drive.

Read more about the Kenepuru Interchange.

Porirua City’s link roads

If you’re out and about Porirua you’ll have noticed a lot of road works – particularly around Waitangirua and Whitby. This is due to the construction of the new Porirua City link roads – the Waitangirua Link Road and the Whitby Link Road. 

The link roads – part of Porirua City’s local roading network – are the biggest investment we have ever made. 

Once finished these link roads will provide improved access from Wellington, Hutt Valley, and Kapiti Coast to Porirua. 

We expect that the improved access will lead to residential and business growth – which is great news for Porirua’s economy.   

Details of the link roads

The 1.45 kilometre Whitby Link Road will connect to the existing roundabout at the intersection of Navigation and James Cook Drives. An estimated 3,200 vehicles will travel this road each day.

The 2.04 kilometre Waitangirua Link Road will intersect with Warspite Avenue and Niagara Street (near Waitangirua Mall) and be controlled by traffic signals. An estimated 4,900 vehicles will travel this road each day.

Some interesting facts to date:

  • 1.3 million cubic metres of earth moved
  • 11 culverts completed 
  • 3 structures completed
  • 4 main interchanges underway
  • 1572 linear metres of gas pipe relocations completed 
  • 2.9 kilometres of stream diversions completed 
  • 550+ contractors and permanent staff involved in the project
  • 27 kilometres to cover
  • 150 visits a week to the Transmission Gully mobile visitor centre in Cobham Court