Transmission Gully Motorway
Client/s: Wellington Gateway Partnership (WGP)
Location: Porirua, NZ
Services: CMT & Geotechnical
Construction Sciences Unit:
The Transmission Gully motorway project was delivered by Wellington Gateway Partnership (WGP) in partnership with the New Zealand Government. Transmission Gully is the first motorway in New Zealand to be constructed on behalf of the New Zealand Government under a Public Private Partnership (PPP) contract. A key part of the Wellington Northern Corridor, the project is one of the most significant single pieces of new road construction in the lower North Island.
Built to demanding specifications, the design and construction of the Transmission Gully motorway reflects the need for another route between Wellington and the lower and central North Island that will be safer and more reliable for motorists and better able to resist and recover from earthquakes and storms. The $1.25 billion project is highly complex, with difficult and steep terrain requiring large-scale earthworks during construction of the project. The 27 kilometre four-lane motorway required twenty-five new structures equating to a total length of more than a kilometre width. The largest of these, the Cannons Creek Bridge, stretched 230 metres in length and sit 60 metres above the valley floor.
Construction Sciences established a laboratory in Wellington, New Zealand to conduct all earthworks testing for the Transmission Gully (TG) project and have now moved into pavements testing as well. The motorway was completed and opened to the public late 2021. The Construction Sciences NZ Team delivered a high level of service to the TG project, and developed professional relationships with other NZ construction companies in order to develop on-going business opportunities and presence in New Zealand.