Te Aranui o Te Rangihaeata – the Transmission Gully motorway connects with the existing State Highway 1 (via the Johnsonville–Porirua motorway) at Kenepuru.
When travelling north, motorists should use the left lanes to continue on SH1 via the Transmission Gully motorway, or the right lanes to continue on State Highway 59.
Northbound motorists travelling to Porirua City Plimmerton should use SH59 and the off-ramp at Mungavin Avenue. Those travelling to Waitangirua/Whitby, SH58 or Kāpiti should use the Transmission Gully motorway.
The Transmission Gully motorway merges with SH59 just south of the Kenepuru Interchange. The merging lanes here resemble the configuration at the bottom of Ngauranga where State Highway 1 and 2 come together.
