Southern Airport Line just makes sense

Before the Planning Committee started yesterday I was having a discussion with Orakei Ward Councillor Desley Simpson over what project should be next given the Government will be funding their contribution to the City Rail Link in their upcoming Budget. I stated that the Manukau to Airport via Puhinui Busway should be next off the rank given congestion issues to, from and within the Airport complex (this includes the industrial complex along State Highway 20A). My reasoning was that this Busway is easy and cheap to build (in comparison to other projects) and utilises existing transit lines very well such as the Southern and Eastern Lines (that also connect to the Western Line and the Northern Busway). This is remembering we are not just focusing on passengers at terminals but more so the workers.

In mentioning this I was asked to look at a more comprehensive package. So introducing the Southern Airport Line.

The Southern Airport Line

The Southern Airport Line takes its name from its two predecessors: the Botany Line and the current Bus Improvements (Airport – Manukau – Botany) so stated in the Auckland Transport Alignment Project (ATAP).

The Southern Airport Line would start as the bus connection from Manukau to the Airport via Puhinui Station (and be possibly funded from the proposed ATEED Levy (the wrongly called Bed Tax)) before being fully upgraded to Light Rail (forming part of a Light Rail network to the airport from both the City Centre via Dominion Road and of course Botany and Manukau in the South.) Now I will get to the ATEED Levy to help pay for stage one of the Southern Airport Line in a moment.

So again what we looking at here as the next project off the rank now that the City Rail Link is a go is the Southern Airport Line. The Southern Airport Line starts as a bus connection from Manukau to the Airport via Puhinui Station. Then in time the bus connection is then upgraded to a fully fledged light rail line no doubt in time to connect up with the Airport LRT Line to the City Centre via Dominion Road and a LRT line from Manukau Panmure via Botany. This in turn would give the South-East, the South-West, and the lower Isthmus a fully integrated Light Rail Transit system that connects to the heavy rail system and major bus hubs like Manukau Bus/Rail Station.

To me and Desley Simpson the Southern Airport Line starting as a bus connection then going to full Light Rail just makes sense especially as the next project off the rank post City Rail Link. The Southern Airport Line fulfils three key aspects lacking in transit to the Airport complex:

1. Connecting Southern Auckland and Howick workers to the Airport whether via Puhinui Station if coming up on the rail line or via Manukau Bus Station if using local South Auckland busses or the bus from Botany
2. Connections to the City Centre, Northern Busway or the Western Line via Puhinui and Britomart Stations on the Southern or Eastern Lines
3. Tourist connections from the Airport to Puhinui Station to then either go north or south on the rail line or to Manukau Bus Station to link up with Inter City busses

Getting the Southern Airport Line off the ground would be a good quick win as the City continues to prepare for the Light Rail Line from the North (at least 10 years). With help of Central Government there is no reason to get the Southern Airport Line running by 2020.

ATEED Tax to fund it?

From the Airport to Botany via Puhinui and Manukau is $319m according to the ATAP document. Now I am going to assume given little development west of Manukau it would be $30 million for Puhinui Interchange (Manukau Bus Station is around ~$27m) and $100m for the busway from Puhinui to the Airport (Puhinui to Manukau would be 24/7 bus lanes). So $130m total. The ATEED Levy is meant to raise $28m/year and is designed to fund tourist and economic infrastructure in benefit of the City. Given the Southern Airport Line is a Capital Expenditure Project (CAPEX) it is funded by debt and repaid through the life of the asset. $28/m year on a very quick tourist and economic win that The Southern Airport Line is would repay that CAPEX in just 5 years. Given the busway is alongside SH20B NZTA could or rather should chip in as well lessening the cost on the ATEED levy.  Councillor Simpson believes The Southern Airport Line would be a good project for the ATEED levy as a possible example.

I would call this a very smart investment of the levy to pay for a crucial piece of infrastructure post City Rail Link.

Station to become major interchange

Those who travel the Southern and Manukau Lines in Auckland wouldn’t think much of Puhinui Station. Puhinui current sits in between the larger Papatoetoe, Homai and Manukau Stations all which serve as interchanges in some form. While Puhinui Station serves as a transfer point between the Southern and Manukau Lines its role could be a whole lot bigger within the next decade.

Let’s take a look at Puhinui Station and the surrounds:

Puhinui sits prime on major transport routes to both Manukau City Centre and the Airport complex. There is also sufficient enough land belonging to Kiwi Rail to build a proper interchange at Puhinui Station with four platforms and an extra track free for freight trains to bypass the station. This is made possible with four mains and a loop running through the interchange site. Technically the Fourth Main (the Third Main on the left hand side would be kept clear for freight) would service Platform Three with an extra loop servicing Platform Four as demand allows but none the less we will need four Mains between Wiri and Otahuhu to get best use out of Puhinui Interchange.

The Four Platforms

This is how I have allocated the platforms at Puhinui:

As I noted earlier I have kept the Third Main on the airport side clear of any platforms to allow freight trains to run through the Interchange area unimpeded. The existing two Mains plus the Fourth Main take up Platforms 1-3 to service commuter, airport and inter-city patronage with an extra loop on the Manukau side forming Platform Four if demand ever warranted another platform (such as an inter city train heading south and keeping the other Mains clear given the extra loading time that might be needed).

The yellow is the interchange area while the grey is the bus line to and from the Airport remembering the interchange will need to be able to service Light Rail when the time comes to turn the Southern Airport Line from a bus-way to  Light Rail Transit line.

How Puhinui Interchange will look in a wider context. The white lines are the two existing Mains with the black the Third and Fourth Mains in utilisation. You can see where the new platform along with a loop track goes keeping the Third Main entirely clear for freight trains. The Third Main also allows for the electric passenger trains to enter and leave the Wiri depot without impeding on the other three Mains.

This is how Puhinui Interchange would interact with Manukau Station and the Southern Airport Line from Manukau to the Airport. You will also notice that I have added the Manukau South Link back in there allowing services from Pukekohe and Papakura to Manukau directly without a transfer at Puhinui Station. With Puhinui Station set to be a major interchange handling commuter, inter-city and airport traffic, re-directing Manukau passengers away from Puhinui Station through a direct connection to Manukau from the South would ease loading pressures at Puhinui.

So the economics of the Manukau South Link do make a comeback with the Puhinui Interchange and the Southern Airport Line.