Auckland Airport Public Transport access is a geometric problem with a two sided solution. There are two immediate sets of catchments, East and North, plus a city-wide overlay then a region-wide one. The Airport is a natural terminus (excuse the pun), because short of looping around there are no destinations beyond the airport. It is a natural end of the line. We addressed this geometry in the Congestion Free Network with the network pattern shown below:
One line east to the catchments of Manukau, Botany, and Howick, and another north to Mangere, the Isthmus, and the City Centre. These lines also intersect with all four current Metro rail services, shown below in their post CRL 2-line pattern. All trains will get you to the planes; via an upgraded connection at Puhinui on the eastern/southern lines, or the CRL stations and Onehunga via Light Rail. This, plus the catchments these two new routes serve directly, vastly increases the accessibility of the airport precinct to the wider city.
We advocate for this pattern because, done well, it will provide the greatest number of people with the highest quality of access to this important destination as part of a whole network, while also offering a high quality access to many other destinations. This is network thinking, not just single route or special journey focus. This pattern enables, at reasonable cost to the city, a full grid of high frequency high quality routes, that serves every kind of rider, to every kind of destination, as well as possible within the constraints of our city’s geometry.
In our current plan we have these as two separate routes, and indeed two different kinds of vehicle, however they could be run as a single service with the same mode, either straight away or in the future. That is partly a operational decision, and partly an investment one. We concluded that the demand and the constraints of the northern route justified Light Rail, but the eastern could be Rapid Bus at least to begin with. This is certainly a decision that is contestable. Regardless, we also don’t see any particular need to through route the service at the Airport. Terminating at the Terminus is logical. Transferring between very frequent, legible, and direct services is at the heart of this network idea.
And it is an idea that is key to all of the world’s great urban transit networks. Each line on Transport for London’s system, for example, is discrete (I know there are a few exceptions to this). The trains stay on their respective lines and the passengers make up each individual journey by transferring between separate services. This network has been built up over more than a century and a half and is made up off all sorts of varying train types and technologies, yet this is irrelevant to the success of the system, because interoperability is achieved though passengers changing routes, not the vehicles. The soon to open Elizabeth Line (Crossrail) trains, for example, cannot and will not run on any Tube line. Clarity, line legibility, and directness of individual services make for the most effective whole network.
Users being individual and all having separate motivations and desires are the best point in a transit system to place flexibility, and perhaps surprisingly that flexibility flourishes best on a fixed and entirely predictable network; one where users can be certain about each route in order to switch between them at will. Or perhaps that is only a surprising idea in a culture dominated by car transport: a system founded on the completely opposite idea where the network is the point of flexibility and vehicle the point of fixity.
The quality of the connection matters enormously in a transfer based network. Firstly the frequency of the lines that make up the network need to be high, at least at 10 minute intervals, ideally better. And the physical ease, safety, and legibility of the transfer points also all need to be very high. So in this case a brand new Puhinui Interchange will be required, one that facilitates switching swiftly and easily between the main rail service and the new east-west one.
Below is a detail from our recently released Regional Rapid Rail proposal (this is a schematic not a map, please don’t fuss about the background) highlighting the potential of this currently very humble point on the Auckland rail network. The Puhinui transfer means that every southern and eastern line train can have an airplane symbol next to it, but it also makes every intercity train from the south is also a; train to the planes. Furthermore, because with the now funded additional track on the Auckland network, new intercity and express services will be possible, reducing journey times from Britomart to Puhinui Station to as short as 16 minutes (non-stop as envisaged on intercity services). From Puhinui Station to the Airport should take about 6 minutes, so allowing a little time for the connection, rail to the airport on this route should routinely take around 30 mins from the city centre. And very very frequent, with a train at most every 5 minutes, and an express (inter-city) at least every 15 (7.5 mins at the peaks).
This is the power offered by connected rapid transit networks: Direct separate routes + high frequency = fast, yet varied journeys, in an affordable network.