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.

Routes in this feature class represent how Transmission Gully motorway:

• 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.
  

In this feature class, by using Network Analysis tool shortest travelled distance between picked destinations is generated, in purpose to demonstrate how Transmission Gully motorway connecting Wellington better. This information then being shared to public by being embedded into an iFrame in NZTA website.