Airport (Heavy) Rail Via Otahuhu + Botany Line: Our Airport Lines. A Redux

Heavy and light rail give integrated solution


With Mayor Len Brown defying Auckland Transport in stating a decision whether to go heavy or light rail to the Airport has both not been made yet and will be made by the Governing Body of Auckland Council not AT themselves you know Len has been listening more to the community than AT ever has (see: Airport rail link not yet decided – Brown). Social media feedback including at Transport Blog (see: Light Rail Preferred to Airport) is heavily in favour of heavy rail to the Airport whether it be via Otahuhu or from Puhinui/Manukau.

The community favouring heavy rail to the Airport would be in line with a 2012 report showing that (if the loop could not be done) via Otahuhu or Puhinui returned the best benefits for the costs involved as seen below:


But first the comparisons between heavy rail and light rail to the Airport.


The apparent costs:

Travel time airport to Aotea Station: 39.25(LRT) v 42.30(HR)
Travel time airport to Britomart Station: 42.36(LRT) v 40.30(HR)
People in station catchments 2046: 96,471(LRT) v 62,700(HR)
Jobs in station catchments: 83,197(LRT) v 74,492(HR)

Cost: $1.2b – $1.3b(LRT) v $2.6b – $3.0b(HR)
Benefit-cost ratio(BCR): 1.11-1.72(LRT) v 0.37-0.64(HR)


This assumed that the Onehunga Line would be used and extended to the Airport as the heavy rail line package as seen below:



Light-Heavy-rail-to-Aiport-Routes-and-stats-1024x528 Source; Transport Blog
Light Heavy rail to Aiport Routes and stats. -Source; Transport Blog


For light rail the cost does not take into account the tracks needing to be placed down Dominion Road to connect up with the Airport section from Onehunga. So add another $1 billion to the LRT cost to get a more reflective cost for light rail given we have none yet in Auckland while we already have heavy rail.


Cost comparisons:

Rail costs to the Airport Source:
Rail costs to the Airport


Light-Heavy-rail-to-Aiport-BCR Source: Transport Blog
Source: Transport Blog


Again for heavy rail it assumes the expensive track duplication and level crossing removing on the Onehunga Branch Line. It does not assume that more EMU trains would already be in the mix owing to the City Rail Link and hopefully the Pukekohe section of the Southern Line already being electrified. With LRT again it takes into assumption that the Dominion Road section has already been built when it is not even sitting in the budget documents yet, so add that $1b on for a more reflective cost.


As for travel times

Light-Heavy-rail-to-Aiport-Travel-Times Source: Transport Blog
Source: Transport Blog


Taking times from Aotea Station is disingenuous given that Britomart will continue to be the major exchange/interchange for heavy rail, light rail, busses and ferries. So if I am factoring in the North Shore travelling to the Airport Britomart Station would be your starting and finishing point for any Airport Rail run patterns.


Heavy Rail to the Airport via Otahuhu

As I said in my Transport Authorities Shortsighted With Auckland Transport Again – Airport Line post:

We the advocates have probably not helped our case for heavy rail to the Airport either by focusing on the wrong section of the Airport Line (the most expensive part rather than the quick win). In a 2012 report (I will post the main highlights below) it indicated that the full heavy rail loop from Onehunga to the Airport and back to Manukau was the most viable, economical and costly option of the seven options available. The Otahuhu to the Airport option was next in terms of viability, economics and costs with Light Rail and Bus-Only being the worst options (hello irony). However, the rail loop was broken down into two distinct parts. It stated that the Airport to Manukau Line (if the loop was to be done rather than from Otahuhu) should be done first on economics/benefits to cost ratio with Onehunga done later if at all. If Manukau was not going to work (it technically would not if we pursued the Botany Line) then Otahuhu was always going to be the fall back option as Otahuhu allows connections to the South, the Isthmus, the North Shore via Britomart and the Busway, West Auckland via the Western Line and even north-west Auckland by the eventual North West Busway). Howick and Botany were looked after by the Botany Line to Manukau and the Airport.



The option via Otahuhu given its benefits to costs, and the prohibitive costs upgrading the redundant Onehunga Line need to be investigated. This investigation would also go alongside urban renewal in the Mangere area and a business case for the Botany Line to Airport section also touted by Auckland Transport that I will go into further down.

With heavy rail to the Airport via Otahuhu:

  • Run heavy rail from the North Island Main Trunk Line between Otahuhu and Middlemore Stations,
  • The heavy rail line heads south-west through Mangere and Mangere East, before joining the State Highway 20/20A interchange
  • It then follows SH20A through to the Airport complex.

The picture below shows an approximate route of this third option (Airport Rail via Otahuhu)

Close up of the LRT and heavy rail via Onehunga route vs the via Mangere to Otahuhu route
Close up of the LRT and heavy rail via Onehunga route vs the via Mangere to Otahuhu route


As a comparison the following picture runs a comparison of the three options (also indicating where new infrastructure would need to be built)

Airport Line Comparison  Red = LRT proposal by Auckland Transport Black  = Heavy Rail Route proposal Black dash = Via Mangere route to Airport instead of Onehunga Yellow = LRT to Manukau as part of Botany Line or Heavy Rail to Manukau
Airport Line Comparison
Red = LRT proposal by Auckland Transport
Black = Heavy Rail Route proposal
Black dash = Via Mangere route to Airport instead of Onehunga
Yellow = LRT to Manukau as part of Botany Line or Heavy Rail to Manukau


As we can see the level of new infrastructure is large with LRT and equally large extending heavy rail from Onehunga. This is because the main cost comes in a duplication of the Mangere Bridge as well other terrain issues such as the downhill grade from Dominion Road to Onehunga.

Figure 1 shows that heavy rail from Otahuhu to SH20/20A interchange will run “over” 60 houses of which 48 belong to Housing New Zealand. While I fully understand invoking the Public Works Act in this area will disrupt residents an opportunity presents itself through urban renewal in the proposed corridor.

That is with the Proposed Auckland Unitary Plan due to go live later this year the opportunity to form a Mangere Redevelopment Company similar to the current Tamaki Redevelopment Program and kick-start urban renewal in the Mangere/Mangere East area presents itself.

We know through an MBIE report that South Auckland is the fastest growing area in Auckland in terms of population and employment. We also know South Auckland has a high level of socio-economic deprivation and Mangere is not immune from it.

Figure 3 Presentation to the Auckland Development Committee, Dec. 2015

Figure 3 Presentation to the Auckland Development Committee, Dec. 2015
Figure 3 Presentation to the Auckland Development Committee, Dec. 2015


The benefits and costs:

  • An extension of existing infrastructure (heavy rail) to a major employment and destination area – the airport that would allow:
    • A 35-39 minute trip between Britomart and the Airport via Otahuhu compared to realistically up to an hour for LRT via Dominion Road (or up to an hour with the Airport Bus as current)
    • LRT has at most 300 passenger capacity per unit of rolling stock compared to an Electric train 6 car set having a capacity of 750 passengers (375 for a 3-car set)
    • As the airport train passes through Otahuhu Station transfers can be made to allow passengers to head to Manukau Station (approx. 25 minutes) or Papakura in the south (approx. 35mins). LRT via Dominion Road and Heavy Rail via Onehunga do not allow connections to South Auckland thus leaving out a large population catchment.
    • Also as Otahuhu Station contains the soon to be built Otahuhu Bus Interchange the airport trains that pass through would allow passengers to transfer to buses at the interchange widening the catchment of those who could use the Airport Line.
    • Utilisation of already in operation Electric Trains rather than needing to design and build an entire new set of rolling stock as you would for LRT
  • Cost savings:
    • Airport Rail via Otahuhu utilises existing infrastructure including trains that would be extended through to the Airport. No need for design and construction of entirely new infrastructure needed with LRT
    • No costly duplication of the Mangere Bridge as you would need for LRT and heavy rail from Onehunga (so $520m saved)
    • No engineering difficulties faced with LRT down SH20 from Dominion Road to Onehunga and with heavy rail duplication on the Onehunga Line
    • Time savings as heavy rail is fully grade separated from roads and road traffic whereas LRT shares the road space along the Dominion Road corridor slowing it down
  • Urban Renewal:
    • As the Airport Line and its subsequent stations from Otahuhu to the Airport run through Mangere the value in residential property uplifts in response to be close to a high quality rapid transit line. This value uplift especially if the Unitary Plan zoning allows it triggers the demand for investment into housing stock and most often intensification. Given that Housing New Zealand owns most of the land in the Airport Line area the opportunity for urban renewal and intensification on what is poorly utilised land is an opportunity HNZ and the Government should not ignore
    • Mangere is surrounded by four large employment centres as pictured below. The urban renewal prospects to maximise land use as well as those centres connected one way or the other via the Airport Line (at least for part of the journey) would go some steps in the Government’s agenda lifting people out of hardship


The suggestive run pattern using heavy rail via Otahuhu:

Airport via Otahuhu Running route. Two trains per hour in each direction (clockwise and counter clockwise) giving a total of 4 trains an hour to and from the Airport and Britomart
Airport via Otahuhu Running route.
Three trains per hour in each direction (clockwise and counter-clockwise) giving a total of 6 trains an hour to and from the Airport and Britomart

Note: The train would not stop at Mt Eden so the Western Line will need to transfer at Newmarket or Aotea Station to reach the Airport Line.

The indicative run pattern is three trains an hour going clockwise with another three going anti clockwise giving six trains an hour (every 10 minutes) at the Airport, Otahuhu Interchange (which includes the soon to open bus station component) and Britomart where ferry and bus passengers (especially from the North Shore) can interchange to and from the Airport Line. As pointed above heavy rail via Otahuhu also allows someone like me to catch a standard Southern Line train from Papakura and transfer at Otahuhu to continue to the airport meaning I get to miss the parking lots that are State Highways 1, 20 and 20B.

To widen the catchment of the via Otahuhu option local busses would run in the area linking up with the heavy rail system:

Airport Line with Sky Train and buses Black = Heavy Rail Connection Blue = Buses Yellow = Sky Train or Heavy Rail
Airport Line with Sky Train and buses
Black = Heavy Rail Connection
Blue = Buses
Yellow = Sky Train or Heavy Rail


Remembering that busses link up with:

  • Papatoetoe Station
  • Otahuhu Interchange
  • Manukau Interchange
  • What would be a Mangere Interchange at Bader Drive where Mangere Town Centre is located
  • Onehunga Station where LRT from Dominion Road would possible terminate in the long run.


The important being that Britomart to the Airport via Otahuhu is 35 minutes fully grade separated from any roads that light rail would suffer from. Papakura to Otahuhu is about 22 minutes and the Otahuhu to Airport leg should be 15 minutes giving a combined time of 37 minutes without me having to be stuck on the State Highway network.

So as you can see heavy rail via Otahuhu is pretty universal with its connections and run efficiency.


Botany Line

Auckland Transport seem willing to investigate light rail from Botany to the Airport via Manukau. The suggestive route pattern would be:

Light-Heavy-rail-to-Aiport-link-to-east Source: Transport Blog
Source: Transport Blog


Interesting proposal from Auckland Transport although it differs slightly to the Botany Line proposal I had:

None-the-less the Botany to Airport via Manukau LRT Line is definitely worth investigation to see if it can be brought online the same time the Airport Line via Otahuhu is so that we have a fully integrated transport package to the airport that includes (for once) redundancy capacity of either mode fails for some reason. One thing I will mention is that if Auckland Transport are serious about a Botany Line to the Airport they might as well forget the busway from Panmure to Botany and just whole hog the entire line as Light Rail. Dig one and construct once the right time.


As I see it the best option that factors in community feedback and involvement while maximising benefits to costs would be the combined and integrated package of heavy rail from Otahuhu to the Airport alongside the Botany Line from Botany to the Airport via Manukau. The universal connection of the Otahuhu option for heavy rail that utilises the three main lines (Southern, Western and Eastern) alongside the Botany Line connecting the east to Manukau, the Eastern Line (and later Southern Line) and the Airport are winners to me in the integrated transport and urban development department.

Now for Council and Central Government to get their acts together to deliver a universal connected integrated transport (and urban renewal) package to and from the Airport. No more follies and no more half arsing that New Zealand is famous for please.


EMU savings