NZTA Board Paper On Next Bridge


An NZTA board paper on the next Auckland harbour crossing emphasises that another road bridge is the cost-effective solution but does not make any recommendation.

“The significant issue becomes one of amenity, Aucklanders’long-term vision for the waterfront and whether or not Auckland wants a new iconic bridge or is prepared to contribute towards tunnels as the more expensive solution,” says the board paper.

The paper, obtained under the Official Information Act, says putting rail aside, the options therefore distil down to:

  1. Replacing the outer spans on the existing bridge without building an additional crossing; . The first option has limitations because of the loss of crossing capacity during construction and the inability to provide for growth.
  2. Removing the old bridge and building a larger iconic bridge slightly further to the east (ie ANZAC Bridge proposal);. The second option is higher cost and has lower resilience.
  3. Building a new bridge slightly to the east of the current bridge but retaining the existing bridge; The iconic bridge could be built in this option.
  4. Retaining the existing bridge and building two tunnels in the corridor for which route protection is underway;  There is a large difference in cost between a new bridge ($3.9B) and new tunnels ($5.2B).

The B/C ratios are 0.6.and 0.4 respectively. “Therefore, the necessary cross harbour capacity and functionality can be provided most cost effectively through the provision of a road bridge.”

But it adds:

“These BCRs should be viewed in the context of the wider need for a new crossing and the potential funding opportunities and the work completed to date has further confirmed the viability of funding the infrastructure through a range of funding mechanisms. The present value cost difference of a bridge $410 million less than a tunnel.

There are, however, other important factors in the analysis that are more difficult to quantify at this point that have potential to partially close the gap between bridge and tunnel. These include issues such as visual, noise and air quality impacts for residents in the vicinity of a bridge, functionality for marine industry and marine recreational users of Westhaven and Wynyard and the fact that the Waitemata Harbour is part of the Department of Conservation–administered Hauraki Gulf Marine Park. These factors impact in particular on the ability to consent the crossing with minimal risk to the design approach that NZTA would wish to take for a given form of crossing.

While a large number of mitigation costs have been included in both options, the outcome and requirements imposed from a consenting process are riskier for a bridge compared to a tunnel. These risks are likely to have a greater impact under scenarios where the NZTA would like to advance the crossing in the medium as opposed to the long term.

The funding options that are available for this project indicate that either form of crossing could be successfully funded. In particular, there is sufficient capacity, especially given the level of toll revenues possible, to reflect any preference that the region may have to advance the more expensive tunnel option.

There is no single funding source that can adequately fund an additional crossing. Any decision on the timing and method of crossing will ultimately be a government decision. Therefore recommendations on the form of crossing need to be informed by the Government’s view of the funding options.

The NLTF could meet a proportion of the costs with the remainder funded by debt. There are a number of viable options for servicing the debt and these need to be discussed with Government, Minister and Auckland Council as regional contributions and alternative funding mechanisms such as tolling are likely to be required.

Funding an AWHC is likely to have an opportunity cost in terms of affordability for other projects which will impact on the land use aspirations in the Auckland Plan.

The trade off of an additional bridge versus visual amenity was included in the NZTA study and there is little evidence to support the selection of the more expensive tunnel option in this regard. However as visual amenity is subjective it is important to consider input from Auckland Council in terms of their plans for the CBD and Waterfront.

In relation to the tunnels, the paper notes that 2 Notices of Requirement were lodged to protect the bored tunne) route in December 2009. Both Councils have since issued the NZTA section 92 further information requests and the NZTA confirmed that responses would be provided by late 2010.

“The outcome of the NZTA, Minister’s consideration and consultation with the Government and the Auckland Council will guide us in relation to what we do with the NoR currently served. Responses to the section 92 requests will need to be delayed to after April 2011.

“However, the responses cannot be extended indefinitely and the timeframe is already well beyond the norm for providing the level of information requested.

“In order to avoid adverse publicity, the NZTA will need to have confirmed that the Government is either pursuing the tunnel designation or withdrawing the tunnel option and pursuing a bridge alternative, prior to public notification of the current NoR. NZTA will need Auckland Council’s assistance in delaying public notification beyond April 2011.”

On the issue of  whether the crossing can be funded and what are the funding options:

The AWHC will represent one of New Zealand’s largest ever infrastructure projects with the defined bridge option (in Net Present Value (NPV) terms) costing $1.16 billion NPV and the defined tunnel option costing $1.57 billion NPV. The National Land Transport Fund (NLTF) meets 100% of the cost of almost all state highway projects via a Pay-as-You-Go (PAYGO) method of financing – the costs of infrastructure projects are usually met from the revenues collected in the same year as construction. The NLTF presently invests around $1.5 billion per year in state highway construction, maintenance and renewal.

On this basis, the cost of either option could not be met from the NLTF using PAYGO alone without a significant increase in NLTF revenue, probably coupled with a reprioritisation of funds.

However, there is considerable scope for the NLTF to meet a proportion of the cost of the crossing, with the remainder funded via debt. There are a number of viable options that exist for servicing and repayment of that debt, including tolls, or potentially covering the cost from future NLTF revenues.

Overall, debt markets for both public and private debt are expected to remain constrained in the short to medium term (to at least 2013/14). The appetite for government borrowing for many projects is also presently constrained due to the need to debt-finance some operating expenditure. Longer term forecasts point to both the availability of debt, and government constraints on borrowing improving over time.

There are also a number of alternative funding mechanisms available to provide either up-front funding, or service either public or private borrowing. These include tax increment finance (TIF) measures and rates funding.

Overall, no technical or financial reason is apparent as to why funding could not be available for the crossing. It is, however, unlikely that a single source of funds would meet the costs, and decisions on availability of funds would also depend on the overall fiscal and economic situation at the time funds were sought, along with other transport and non-transport priorities.

On the question: does Auckland need another crossing? It says: Auckland has been identified by the Government as being the economic powerhouse of New Zealand, and the AWHC has been included in the National Infrastructure Plan. The Auckland Harbour Bridge (AHB) represents a critical enabler of urban mobility for people and freight in the Auckland region. At present, the bridge handles 168,000 vehicles per day, making it critical to the economic wellbeing of Auckland and New Zealand.

  • There is a compelling need to consider additional capacity on State Highway 1 (SH1) between the Auckland central business district (CBD) and the North Shore as: The route already has a level of service (LOS) during peak times of E/F – the most congested measure;
  • Population and travel demand growth is forecast to increase by around 22% (40,000 vehicles per day) to 2041 which will significantly impact on the ability of the route to provide economic benefits to commuters and freight; and
  • The resilience of the network is an ongoing concern in terms of:
  • Managing the future loads on the current AHB and associated maintenance needs;
  • Providing an ability to manage and recover from significant network disruption; and
  • Adequately balancing the needs of both CBD-bound commuters, public transport (PT) and port-bound freight, with north-south traffic that does not originate or terminate in the CBD.

The present value of economic benefits over a 30 year analysis period NPV of additional capacity are around:

  • $300 million in travel time savings;
  • $80 million in decongestion benefits
  • $9 million in travel time reliability benefits.

In addition, present value benefits from agglomeration are around $250 million, and the modelling demonstrates movement in land-use to key growth nodes such as Takapuna, while continuing to grow other nodes such as the CBD.

The critical aspect of these benefits is that they are derived from an increase in capacity and connectivity over a reasonably small stretch of the network. Additional capacity or network optimisation in the CBD (including ability to take additional traffic from the Northern Busway, Central Motorway Junction (CMJ) and North Shore connections would widen and deepen the economic benefits derived from additional capacity.

The economic appraisals of major transport infrastructure schemes such as the AWHC cannot be deemed to fairly reflect their merits (or otherwise) unless explicit modelling of different subsequent economic activity and different subsequent transport investment decisions is undertaken. If the AWHC were considered as part of a particularly broad strategy of infrastructure investment then perhaps even modelling of population and demography would be required to capture the full spectrum of benefits.

Rail cannot be carried on the existing bridge because of the lack of strength and the steep gradient. Rail should be provided for separately and in a tunnel because it does not need to be built until post 2040 and bridge gradients are generally too steep;

It says the existing bridge should be retained as an alternative crossing of the harbour providing an arterial link between the North Shore and the CBD and to provide network resilience;

The ANZAC proposal - a bridge alignment between Esmonde Road and Wynyard Point  was considered during the option generation stage of the project. However, in determining feasible options to include in the long list for assessment, this proposal was not taken forward due to a number of significant issues.

  1. A bridge structure on such an alignment would significantly impact on the planned and future development aspirations of the Wynyard Quarter
  2. Early conclusions from the Network Plan workstream indicate that there is capacity in the Northern Busway till at least 2041 and that any rail service would come on-line after this date. Moreover, the cost of establishing a rail network on the North Shore is significant and it is unlikely a business case could be established to support lead investment in cross harbour rail at this time. The ANZAC Bridge proposal assumes rail on a new bridge on opening which does not correlate with the conclusions that came from both the Network Plan and AWHC shortlisting exercise.
  3. The ANZAC Bridge proposal requires removal of the existing Harbour Bridge. This is counter to the NZTA’s objectives of providing network resilience. In addition removal of a valuable asset with will be able to provide an important transport function indefinitely to provide a similar transport function on a new structure unnecessarily does not offer good value for money. In addition, the existing bridge, in itself, is an iconic and important structure and as such there would be significant local and national resistance for its unnecessary removal. The ANZAC Group’s rationale for removal is that this would enable realisation of substantial land values at St Mary’s Bay to contribute to the project. The NZTA’s analysis suggests that whilst this could be achieved, regional and Maori and local stakeholder interests would likely limit what could be realised in terms of value from the land
  4. A structure to Wynyard Point would then require substantial “Cut and Cover” works through Wynyard Quarter to link with the State Highway at Victoria Park. The cost of this work coupled with property requirements and appropriate mitigation would not offer value for money over other more direct bridge alignment options.

On the issue of whether the existing bridge could be strengthened the paper says:

Investigations to date have concluded that replacing the “Clip-Ons’ (extension bridges) on the existing Harbour Bridge is very complex and would involve closing lanes for a very long period. This complexity is due to the fact that the supports for the extension bridges are tied together through the main bridge piers to balance the load. As such, it is highly likely that both extension bridges would need to be taken off at the same time. This would have serious implications for the Auckland economy, as the capacity of the existing Harbour Bridge would potentially be reduced by up to 4 lanes for a period of 1-2 years. Furthermore, replacing the extension bridges would be a very expensive exercise, costing hundreds of millions of dollars.

Therefore, replacing the extension bridges is considered unacceptable and the existing Harbour Bridge will be managed to avoid any future need for replacement.

In short, whilst technically possible to replace the existing box girder extension structures, it is considered highly impractical for the following reasons:

  • The ability to safely deconstruct the extension bridges is constrained by the ‘self- balancing’ function of the two extension bridges. The supports for the “Clip-ons” are tied together through the main bridge piers to balance the load. For instance the ability to deconstruct one and still safely operate the other may not be possible. This would also impact on the network operations and functionality during construction
  • It is expected that replacement of the clip-ons would take up to 2 years, and certainly more than 1 year. Without an alternative crossing the capacity would need to be managed to meet demand and maintain operations.

The issue of carrying freight over the bridge gets some attention.

The Port is an important hub for transporting freight to and from New Zealand. The Auckland Harbour Bridge (AHB) plays a key role linking the Port and northern parts of Auckland and beyond. It caters for the transportation of a large proportion of exports out of and imports into New Zealand. This makes the AHB crossing a frequently used route by heavy road vehicles carrying freight.

The total gross weight of road freight imported and exported through the Port in 2010 was 6.3 million tonnes. The Port facilitates 37% of total goods passing through New Zealand seaports by value, and 14% by gross weight3.

It is interesting to note that the value per tonne of goods imported and exported via the Port is 2.73 times the value of goods through seaports throughout all of New Zealand. This statistic indicates that higher value products in New Zealand are generally brought into and out of the country via road freight to and from the Port. This suggests that using national labour productivity figures for the Auckland road freight industry may underestimate Auckland road freight GDP.

There are, on average, a total of 4,000 freight trips daily across the AHB as a means of transporting goods between Auckland city centre and areas to the north. There are likely to be increasing restrictions on heavy vehicles using the bridge as a mean of transporting freight due to the aging nature of the bridge itself. Already heavy vehicles are limited to using only the middle lanes of the bridge rather than the outside (clip-on lanes). If restrictions on heavy vehicles crossing the AHB were increased, heavy vehicles would have to use the Western Ring Route (WRR) to get from the Port to the North Shore (Constellation Drive).

The impact of restrictions on trucks crossing the AHB are estimated as up to $63 million in PV terms over the next 30 years. Crucially, however, this figure does not take into account the likely increase in congestion on the WRR, or the downstream impacts on the businesses that rely on the road freight industry.

It is thus concluded that although the figures above are relatively low, they are likely to be markedly higher in total. There is significant scope for an examination of the broader impacts of restrictions through increased congestion on the WRR, and through impacts on other industries relying on the road freight industry.

The recommendations before the board were that it:

a. agrees that no decision will be made regarding the recommendation of crossing option to the Government until after consultation with the Government, Minister, key partners and stakeholders has taken place;

b. agrees that a decision on route protection and in the long-term the timing and construction of an AWHC, are a Government decision informed by NZTA and Auckland Council;

c. agrees that the process of recommending a preferred crossing option to the Government needs to be integrated with Auckland Council’s process for preparing its first Auckland Plan;

d. agrees that the Chairman and CEO consult with Minister, Government, Auckland Council, Auckland Transport, MoT/Treasury, KiwiRail and Iwi about the form, timing and funding of an AWHC and its integration with the Auckland Plan before the end of January 2011;e. agrees that the NZTA should prepare a paper before the end of January 2011 for the Minister to brief Cabinet and also to brief Mayor Brown and the Auckland Transport Committee Chair on the report findings;

f. agrees that a CEO Forum Group be formed to replace the original political reference group which was disestablished prior to the recent local authority election;

g. agrees that subject to agreement on timing with the Minister and Mayor Brown information about the crossing options should be shared with the wider community in February or March 2011;

h. agrees that the Auckland Council assistance should be sought in deferring the Tunnel Notice of Requirement process until a choice of option is made, with the community, NZTA and Government;

i. agrees that a report for the Minister and NZTA Board on the outcome of the engagement with Auckland Council and other key partners is required for consideration by April 2011; and

j. agrees to keep this Board paper in committee due to the emerging Board policy regarding the key macro scope items relating to the AWHC Project. The paper is to remain in committee until the completion of the consultation with the Government, Minister, Auckland Council and Auckland Transport.





  1. George D says:

    Solution? First, we need to define the “problem”. I’m very much of the opinion that this is a solution in need of a problem.

  2. Patrick Davis says:

    The BCR’s of 0.6 and 0.4. These look like to me road bridge v road tunnel. It appears that the NZTA has conveniently left out the benefits garnered from rail in their calculations.

  3. Luke says:

    no independent analysis by NZTA of when the bridge is actually required it seems, just spouting Joyces wish-washy stuff about ‘economic growth’ with no proper work to back it up.
    By NZTA’s own reckoning I thought Vic Park and Waterview Connection are supposed to be a big help to congestion on the North Shore. So therefore using current traffic congestion is just wrong.

  4. Patrick R says:

    The people are way out in front of Joyce and others all staring in the rear view mirror:

    Note that Joyce, getting the last word, refers to that ridiculously over priced fantasy scheme clearly cooked up for this very purpose: to make North Shore Rail look too expensive.


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