Ring Road – Wairere Drive extension is a $45 million Hamilton City Council (HCC) project, 75% funded through Waka Kotahi (NZ Transport Agency) subsidies.

The Ring Road – Wairere Drive extension project will provide the final connection of the Hamilton Ring Road between Cambridge Road and Cobham Drive. It includes a full grade separated interchange, with Cobham Drive raised to allow Wairere Drive to pass underneath. Shared walking and cycling paths are provided, connecting to the Hamilton Gardens, Te Awa cycleway, and surrounding parks and reserves. The interchange provides connections for all transport modes to the new Waikato River Bridge and Peacocke development. BBO has been involved from the preliminary design phase through to monitoring of construction, keeping the many key stakeholders' interests at the core of what we do.

The challenge

The BBO design team has had to overcome many challenges, including the constrained site wedged between a gully and a residential suburb, and bisected by SH1 which carries over 25,000 vehicles per day. The project includes innovative raised intersections to improve safety - the first at a major arterial interchange in New Zealand. 

Other challenges met have included contamination from the city’s historic World War 1 munitions factory and asbestos dump sites, and the incorporation of Hamilton City’s future strategic water and wastewater pipelines. The project has also seen significant service relocations including overhead power lines over the Waikato River. The BBO team has worked with Hamilton City Council, Waka Kotahi, and the Contractor to provide good value solutions.

Construction progress can be viewed on Hamilton City Council's YouTube page.


The outcome

The existing stream was relocated to allow the interchange to be constructed. The new stream has been landscaped as a feature with rock and water features, and walking tracks weaving along the banks. Much focus has been placed on water quality and rejuvenation of wildlife, with birds and fish already settling into their new habitat.

When complete the project will support growth within Hamilton by opening up access to the Peacocke Growth Cell and will provide both attractive and safe movement of all transport modes.



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Traffic on the future on and off ramps to enable construction of the new Cobham Drive Overbridge.

WRR 370

Looking north towards the construction of the Cobham Drive bridge substructure.

WRR 422

Looking north east over the pocket park construction and adjacent stream diversion.

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3D Visualization looking south through the completed interchange.


3D Visualization of the completed interchange looking south towards the new Waikato River Bridge and Peacockes development. SH1/ Cobham drive is in in the Foreground.


3D Visualization of the completed interchange looking south towards the new Waikato River Bridge and Peacockes development.


3D Visualization of the completed interchange looking south towards Peacocke Development.