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Project overview

Project introduction

The Causeway Upgrade is a 4.8km long project on Auckland’s Northwestern Motorway (SH16) between Great North Road Interchange and Te Atatu Interchange, and is a key component in completing the Western Ring Route.

  • Estimated project cost

    $100+ million
  • Project type

    Road improvements, Road maintenance
  • Project status


Project updates

Causeway News - September 2015
Project updates, (PDF)
Causeway News - August 2015
Project updates, (PDF)
Causeway News - July 2015
Newsletters, (PDF)
Causeway News - June 2015
Newsletters, (PDF)


The Causeway Upgrade Project involves raising a section of the Northwestern Motorway to prevent flooding and widening it to provide additional capacity. The cycleway alongside the motorway is being raised, widened and upgraded, too.   This project is a key part of the Western Ring Route which once complete, will provide an alternative to SH1, central Auckland and the Auckland Harbour Bridge.  


  • Improved travel time reliability with the addition of more lanes

  • Less flooding on the causeway as the road and cycleway are raised

  • Dedicated bus shoulder lanes for more direct bus trips

  • Improved pedestrian and cyclist access

  • Stormwater treatment installation

Major SH closures and detours

Rosebank Road on-ramp weekend closure and Rosebank Road on-ramp diversion starting from Friday 2 October to approximately four weeks.  Find out more

Patiki Road cycleway detour

From midday on Tuesday 8 September we will detour part of the cycleway so that the existing Patiki Road cycle and pedestrian overbridge can be deconstructed.  Find more information

What is the Causeway Upgrade Project?

The Causeway Upgrade Project is raising the motorway 1.5 metres to prevent flooding and widening it to provide additional capacity and bus shoulder lanes in both directions. The cycleway alongside the motorway is being raised, widened and upgraded, too.   The work is being completed in stages so that disruption to the community, our environment and to traffic is kept to an absolute minimum.

A key consideration of the project is the Motu Manawa – Pollen Island Marine Reserve which runs alongside the project.  The project team works hard to ensures the construction work has as little impact as possible on the marine reserve.

The project links with the Waterview Connection Project to connect the Northwestern Motorway (SH16) with the Southwestern Motorway (SH20).  It is one of four under construction on SH16 and connects with the St Lukes to Great North Road and Te Atatu Interchange Upgrade projects.

How are we raising and widening SH16?

The graphics below show how State Highway 16 between Great North Road and the Whau River Bridge near Te Atatu is being raised and widened.

The Causeway Alliance

The Causeway Alliance is made up of AECOM, Coffey, Fulton Hogan, Leighton Contractors, Jacobs and the NZ Transport Agency, bringing together specialist skills in a range of safety, engineering, design, construction, environmental protection, management, commercial and support disciplines.

The Causeway Upgrade project will be finished along with other projects – being delivered by different project teams for the Transport Agency – at St Lukes, Lincoln Road and the Te Atatu Interchange by the time the Waterview tunnels open in 2017.