While “minor” finishing touches, including surfacing and line marking, would continue through the summer sealing season, the main work had now officially been completed, NZTA said.
NZTA acting regional manager of infrastructure delivery, Darryl Coalter, said the intersection had been the scene of many serious crashes.
“A roundabout was chosen for its proven safety benefits and network resilience. It was also designed with a fourth ‘stub’ to futureproof the connection seamlessly to the planned Cambridge to Piarere expressway.”
The agency estimates that more than 20,000 vehicles use the intersection daily.
NZTA first announced plans of a roundabout at the site in 2021.
Downer was awarded the construction contract in late 2023. Earthworks started in early 2024.
To make way for two pedestrian underpasses, the ground level needed to be raised 4.5 metres, which meant moving 100,000sq m of structural fill.
Downer project manager Craig Lingard said at its peak, up to 7000 tonnes of fill was delivered daily via roughly 130 truck trips.
Lingard said more than 400 people were inducted to the site and over 110,000 hours of work were logged.
The team worked with local mana whenua throughout the project.
At the centre of the roundabout is a 12-metre-high sculpture called Manu Rangimaarie (bird of peace), designed by the late Fred Graham, which celebrates the connection between hapū and iwi to the land and river.