Each segment weighs between 70t and 90t and is being raised into place by a lifting gantry that sits across the top of the viaduct.

Construction of the northbound lanes has started at the southern end of the viaduct. The gantry will work its way northwards and the job is due for completion early next year.

NZTA and its partners - Leighton Contractors, Fulton Hogan, VSL, URS, BECA, Tonkin & Taylor and Boffa Miskell -  are constructing the new viaduct and removing the old one in stages while the busiest section of the Auckland motorway network remains open.