Background: A new harbour crossing is needed for Auckland

Managing Auckland’s cross-harbour traffic flows is one of the major issues facing the region in coming years. The number of vehicles crossing the Harbour Bridge each day rose by over 30 percent in the last 20 years, and similar growth is expected over the coming 20 years. 

This increase is too much for the existing bridge to cope with. Within the next two decades the bridge will reach the limits of what it can carry in terms of weight and volume, and structural fatigue issues on the outer “clip-ons” will likely give rise to unsustainable maintenance costs. Though the central structure of the bridge can remain operational for some time yet, there will come a point in the not too distant future where – as with the clip-ons – the maintenance costs can no longer be justified.

Previously, a tunnel was preferred

Recognising that the existing bridge is an inadequate solution to Auckland’s long-term transport needs, the Government has been researching new harbour crossing options for some time. 

A 2007/2008 NZTA report identified the preferred option as a combination of the existing bridge and at least two new tunnels.  The tunnel option would include up to six general traffic lanes, as well as two rail tracks, and would take the role of SH1.  The existing bridge would remain operational, but could be modified by retiring some of the outer lanes from use and/or adding pedestrian and cycle facilities. The estimated cost of the new tunnels is $3.7-$4.1 billion, while the maintenance costs for the existing bridge are $3.5-$4 million per annum.

But now the new bridge is an equal option

Since then, however, greater consideration has been given to a stand-alone bridge option.  In March 2010, the Government included a new Waitemata Harbour crossing in the list of projects in its National Infrastructure Plan, and stipulated that the new crossing could come in the form of a bridge or tunnels. 

At the same time, NZTA commissioned a further study into bridge and tunnel options.

Our goal is to ensure that a stand-alone bridge – in particular the broader, transformational benefits that it offers – is given adequate consideration in the lead-up to a decision on the harbour crossing.  We are aiming to build public and political support for the new bridge, and for an early construction time-frame.