With a new Government, we are able to have a rethink of some of the Transport priorities for Auckland. One of these is the Additional Waitemata Harbour Crossing project.
This project has gone very quiet as of late, since the Auckland Transport Alignment Project clearly demonstrated it was nowhere near the high priority that NZTA had previously suggested, deferring it by around 20 years well into the third decade.
The ATAP Supporting Information rubbished NZTA’s previous justification for the project’s urgency, highlighting that there is no engineering reason for it to be required:
Although the bridge has been strengthened in the past decade, it has limited ability to cater for ongoing growth in heavy vehicle traffic. Consequently, some level of heavy vehicle management will be needed in the future. Initial work indicates that the economic impacts of this heavy vehicle management on its own are likely to be relatively minor compared to the construction cost of a new crossing.
The NZCID, now Infrastructure New Zealand, commented that the motorway tunnel would provide extremely low value for money in their Transport Solutions for a Growing City Report (page 31):
“The proposed Additional Waitemata Harbour Crossing performs the worst economically, delivering a BCR of 0.4.”
“… The proposed Additional Waitemata Harbour Crossing is throttled at both its northern and southern termination points, constraining its potential. It cannot connect new businesses and communities and it cannot lift the opportunities for the region, as its predecessor, the Auckland Harbour Bridge has done. Consequently, it cannot deliver economic and social benefits consistent with its high cost and these limitations are highlighted by conventional cost benefit analysis which shows a return of 40 cents for every dollar invested.” – Page 63
The business case would likely be even poorer if Smarter Pricing were assumed.
Furthermore, the North Shore Rapid Transit Strategic Case showed that most cross-harbour demand was for the City Centre and Fringe. We also learnt that the Busway was reaching capacity much faster than anticipated by earlier modelling with capacity likely to be reached in the mid to late 2020s.
…by 2026, the joint AT/ NZTA Northern Corridor Improvements (NCI) project is anticipated to have completed the missing section of the busway, constructed a new Rosedale Busway station and provided and additional platform to Constellation Station, therefore improving these deficiencies. Capacity problems are somewhat reduced by 2026 due to implementation of bus infrastructure improvements in the City Centre, however, Albany Station experiences capacity problems. However, by 2026, a significant improvement in city centre bus infrastructure has been assumed. These interventions, while still conceptual in nature and subject to funding commitments, these upgrades are still constrained by signals at intersections. As such even in 2026, soon after implementation the city centre infrastructure is likely to only just provide sufficient capacity to meet demands.
…by 2026, increased patronage on the busway and busway stations is likely to manifest in over capacity conditions and poor operational performance at Albany Station due to large volumes of commencing services in the AM peak which use up a lot of station capacity. Sunnynook Station which has the shortest platforms of all the busway stations will also be experiencing over capacity conditions affecting dwell times. Akoranga Station is also starting to experience congestion by this time
The forecasted cross-harbour trips are also focused heavily on the City Centre and Fringe with very little trips past Penrose. As City Centre parking and street capacity becomes ever more scarce along with the introduction of Smarter Pricing increasing cross-harbour roading capacity doesn’t seem to make more sense at all.
From what I can understand the aim is still a shared road/PT crossing. I think this is a mistake there is also no reason the road/rail components need to be combined for two main reasons:
- The road alignment is not likely to be the best alignment for rail. The tunnel is likely to be very deep at its city end, making a Wynyard Quarter station difficult and also making it hard to link in with the light-rail network proposed between Wynyard, Queen Street, Dominion Road and onto the Airport.
- We will need rail a long time before we need a new road crossing as the busway reaches capacity and as the cross-harbour demand is forecasted to be focused mainly on the City Centre this is a job for spacially efficient rapid transit.
These reasons mean we should reassess building a transit-only crossing first, and also look again at some previous assumptions made around the best alignment for a public transport crossing.
ATAP estimated a tunnelled light rail line connecting from Wynyard Quarter to at least Takapuna at $1,868 million with an extension to Grand Drive Orewa at another $868 million. So that’s $2.7 billion for light rail from Orewa to the City, compared to $3.7 billion for the road tunnels alone. With the new Government committing to Light Rail Wynyard Quarter to the Airport one of the major issues is solved as the North Shore Light Rail can now connect directly into this system.
We should also reconsider making this particular crossing a bridge. As well as being significantly cheaper than tunnelling likely reducing the cost to Takapuna to around $1b, it could allow walking and cycling from the start. A road crossing which could include heavy rail or driverless metro could then be built as a second (or Third) stage when it is needed in the distant future.