Within the Auckland Transport Alignment Process Interim Report is the news that the six lane highway across the harbour as currently planned, the Additional Harbour Crossing, just doesn’t work, and is now at least mortally wounded, if not actually dead.
Clearly a total re-think of ways to serve the growing movement demand between the city and the north east is required. In January the Waterview connection and the supersizing of the North Western will open, and later a new interchange between SH 18 and SH 1 will complete the next road connections between the upper harbour and the wider city.
Additionally the SkyPath, SeaPath, and improvements to ferry services will also be added to the mix for the inner harbour, for the Active modes.
The great missing piece in the movement jigsaw for this part of the city [as elsewhere] is a Rapid Transit connection across the harbour and through the Shore. The case for the next major connection across the harbour utilising the high capacity, smaller foot print, and traffic reduction outcomes of Rapid Transit is now all but made.
Here I want to explore the options for an actually successful harbour crossing, particularly in light of recent announcements about the Mangere/Airport RTN, but also because of the need for a viable near term system that fits into the longer term needs of our growing city. I can’t emphasise this enough; for a system to actually get funded and built it surely must fit both those criteria, and that is not easy.
What follows is an exploration of possibilities done with a fairly broad brush; a high altitude view, with a lot of scope for variation in detail.
In 2012 I wrote a couple of speculative posts proposing the Shore Line as an extension of our current rail network. Here and here. I was interested in looking beyond the CRL to examine future improvements to the Shore and through Mangere to the Airport. In particular in offering an Albany to Airport one seat ride through an east-west CRL II type project, like this:
While there is some elegance to these proposals [and some problems] it is clear that I started from an unexpressed assumption that all future rail systems would be extensions of the current network. This is no longer my view primarily because our current network has very firm structural upper limits for train movements, that means at some point it becomes limiting to try to add ever more arms to this body. Adding an additional high demand area like the North Shore will bring those limits forward, especially to hard to expand pinch points like Newmarket Station and Junction. Remembering too that freight movements are growing on parts of the network too. This isn’t to criticise our re-born urban rail system, it will remain the vital core of Auckland’s RTN, growing quickly post CRL to 50m trips pa. and beyond. But rather to recognise that it needs to be free to serve these core roles, supported by other existing and enhanced networks, and some new ones.
I also suspect that the required crosstown tunnel would be prohibitively expensive, especially when combined with a cross harbour one. Together these costs could be sufficiently high to kill the plan.
Instead, adding a new and complimentary network, making connections by transfer at interchange stations, adds resilience as well as more capacity, in that problems on one network won’t affect the other. This also allows us to tailor the next network to our current demands and utilise all the latest technology and thinking without needing to accommodate it to the physical parameters of the existing system [freedom from the ‘happenstance of yore’].
On the assumption that the current Busway can be relatively easily converted to Light Rail, the obvious opportunity is leverage off AT’s Light Rail plans for a Queen St-Dominion Rd system through Mangere to the Airport so that this:
becomes this, an idea we have explored in the past:
So the return of the highly desirable one-seat ride from Albany to the Airport, on a high catchment spine; the A-Train, but this time via Light Rail, on a combination of higher speed grade separate paths, and high access street running. The advantages and disadvantages of these conditions have been debated at length on previous posts, what I want to examine here are future network possibilities of such a system, because networks are always greater than their parts. However it is worth a visit to this analysis of the recent addition of Light Rail to Paris’ Transit mix on this very issue; degrees of separation, I guess you could call it. Basically it concludes that while it is always better to strive for as much separate running as possible, this needs to be balanced against both capital cost and quality of access. And especially the quantity and quality of the transfer nodes with other major Transit Networks.
It takes just a few seconds looking at the RATP map to see why the Paris trams are so useful. In Paris’s hub-and-spoke transit network, they are the rim of the wheel, connecting the ends of Metro and RER lines in far-flung parts of the region. All nine lines offer at least two stations that connect to other modes of transit. Some offer many more:
|No. of transfers||No. of total stations||Pct. of stations with transfers|
So returning to Auckland and the proposed A Line we can see that while it would be a great complement to our existing fast growing Rail Network, and likely further RTN extensions including AMETI, and the North-Western, it still only connects with it at the four stations indicated with blue dots above. However the possibilities for leveraging off this system to create a second route with a rich abundance of connectedness:
The western section carries along the grade separate SH20 alignment to a new station at Owairaka, then continues to Mt Albert Station, Unitec, and to the future RTN station at Pt Chev on the North-Western line, on-street [The RTN connections are why I prefer this possible extension over one to the metro-centre of New Lynn]. The southern to Puhinui Station and the Manukau City Interchange Station down Lambie Dr, again mostly on its own alignment.
Which of course can be extended to include AMETI:
The simplest idea would be to run these as two overlapping lines A and B, giving the Airport and Mangere great connectivity west, south, north, and east. Direct to the City Centre and great connectivity with every branch of the RTN, including of course the Onehunga line. Or say three lines all converging on the Airport. Such a system is also highly stageable, and you all can haggle over your favourite technology for each part….
The key principle though must be future proofing for upgrades. I think it is vital, for example, that the harbour crossing, if it is to be Light Rail, is built so it can take Light Metro for the time in the future that the demand from the Shore is high enough to justify a tunnel from Wynyard to Aotea Station and the option of implementing a fully driverless system as then it would be 100% grade separate. I’m sure some would like to start straight off with such a system, but I think it is clear that designing systems that can grow with the city is the only viable way forward.
Without trying to put a date on it, below is a pretty good integrated RTN future to aim for:
Rail running at 5min frequencies on the outer lines so a train every 2.5 mins in the CRL and other places [Red and Green]
LRT also at varying frequencies depending on place, perhaps even two routes from Wynyard to the city
More Ferries, Rapid Bus on Gt North Rd and the NW and across the Upper Harbour, although especially from Pt Chev to the city could be LRT too.
When or whether parts of this are Buses or Light Rail, are not so much my focus but rather getting the coverage optimised, and the routes protected.
No doubt it will change but here’s a potential version. Discuss: