This case study is presented as an illustration of certain past project practices, in this case before the publication of the National Alliance Contracting Policy and Guidelines, and in a jurisdiction outside the ambit of this policy and guidelines.
This case study includes views and commentary from Owner and NOP perspectives without any attempt to ensure consistency. By including any case study in the Guidance Note, the Commonwealth Department of Infrastructure and Regional Development does not assert the success or otherwise of the case study project, or that every aspect of the project was exemplary. The matters presented here were selected to provide a good practice example of the issues dealt with in the Guidance Note.
The Manukau Harbour Crossing Project
Auckland, New Zealand
With the vital target of opening ahead of the Rugby World Cup 2011, New Zealand Transport Agency (NZTA) issued an RFP on 20th March 2007 instigating the Manukau Harbour Crossing Project (MHX). This project duplicated the existing Manukau Harbour Bridge and upgraded the adjoining motorway sections and its interchanges. The works form a critical link in Auckland's Western Ring Route - identified as one of seven Roads of National Significance.
The new $230 million duplicate bridge, together with the existing bridge completed in 1983, now provides 10 lanes of traffic directly over the Manukau Harbour - four lanes of general traffic in each direction, plus two bus shoulder lanes. Some 80,000 motorists use the route daily, with travel time reductions of up to 20 minutes in each direction between the airport and the city during peak times. The resulting efficiencies and access to the airport are expected to provide a strong boost to the economy, both regionally and nationally.
The key challenges for the MHX project were:
• Geotechnical - piles founded on weak sandstone and with 60m depth of very soft soils in the Hopua Crater
• Traffic management - maintaining existing traffic flows while constructing additional bridges and traffic lanes, and revising interchange layouts
• Environmental and community - environmental concerns arising from working on the harbour, and in particular the Onehunga foreshore
• Consenting (ie regulatory and planning approvals) risk - impact on designation and resource consents and therefore on start and completion dates. There was significant resistance from the Onehunga community (The Onehunga Enhancement Society, 'TOES') around the encroachment of the Gloucester Park interchange into the harbour.
The Project was delivered by an alliance comprising NZTA21, Fletcher Construction, Beca Infrastructure and Higgins Contractors.
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21 NZTA was formed in 2008 from two entities, Land Transport New Zealand and Transit New Zealand. Transit New Zealand had initiated the project.