Central Motorway Junction and Grafton Gully
Connecting Auckland’s motorway network
Providing a direct motorway link between the Port of Auckland and the Southern Motorway, this project kicked-off the Transport Agency’s large-scale Central Motorway Junction (CMJ) improvements. Significantly, the project was the first major road construction alliance in New Zealand, and its success opened the door to this now-popular delivery mechanism.
the project was the first major road construction alliance in New Zealand, and its success opened the door to this now-popular delivery mechanism
Undertaken on one of New Zealand’s busiest sections of motorway used by over 200,000 vehicles per day, we tackled a significant work scope: major earthworks, over 2km of new motorway with two or three lanes in each direction; four over-bridge structures connecting local roads above the motorway; large concrete retaining walls; and several new ramps connecting the motorway to local roads.
We delivered the project as part of the Freeflow alliance alongside Beca, the New Zealand Transport Agency, and Higgins Contractors. The alliance’s strong performance led to the award of a major variation to the contract, CMJ Stage 1, which involved widening the existing section of the Southern Motorway between Grafton Road and Gilles Ave.
The first of the Transport Agency’s two-stage CMJ enhancement, CMJ Stage 1 provided an additional lane in each direction on the Southern Motorway. This required cutting several metres out of basalt rock faces, seismic strengthening of existing viaduct structures, widening over-bridges, installation of new retaining walls, and fitting new barriers and lighting – all in a live motorway environment.