The Southern Rapid Transit project opening Southern Auckland and even the Isthmus
With the high potential of the City Centre to Mangere – Queen Street to Onehunga via Dominion Road section of Light Rail stalling (see: City Centre to Mangere Light Rail (City Centre to Onehunga section) Dead in the Water. Project Stalls) it does not mean Light Rail dies in Auckland. There are still two areas primed for Light Rail that could have it delivered with one of the areas delivered for the fraction of the cost of City Centre to Mangere –
Queen Street to Onehunga via Dominion Road. The two areas primed for Light Rail are: Airport to Botany, and City Centre to Mangere – Onehunga to Airport. I have not included North West Light Rail as that needs to make its way down Queen Street which even if NW LRT was lined up still faces the same complications as CC2M at that end as well.
Light Rail for $2.5 billion?
Could Light Rail be delivered for around $2.5 billion and more to the point could that $2.5b deliver us 20km worth of light rail? Using price of $75m/per kilometre (I’ll get to why that price and not a higher unit price) I will attempt to break down delivering two Lines (that I have called The Southern Rapid Transit Concept) for the $2.5b price.
First of all where is that 20km of LRT going? It is all in Southern Auckland given the issues with City Centre to Mangere over on the Isthmus. The 20km of initial Light Rail is actually parts of the two wider Lines that would be built later on. In other words the 20km of LRT consists of:
- City Centre to Mangere – Onehunga to Airport section
- Airport to Botany – Airport to Manukau section
The graphic below illustrates the two sections (purple for CC2M and red for A2B):

The Black is Airport to Botany – Manukau to Botany section of A2B and the price tag to deliver that at $75m/per km is $675m.
Both sections of Light Rail (Airport to Onehunga and Manukau) are around 9.5km long. Yes I know that gives us 19km but given the Airport end of City Centre to Mangere is unconfirmed yet due to the Northern Runway being built I have given myself an extra kilometre for contingency – hence 20km.
At $75m/km for 20km the price tag comes in at $1.5 billion leaving me $500m to work with. Assuming the depot on State Highway 20B comes in at $150m (based on the Wiri Depot for our heavy rail passenger trains, some inflation post 2013 and the requirement this Light Rail depot will be a heavy depot with a foundry attached for heavy maintenance of the LRT rolling stock)) this means I have $350m for stations, sections of LRT that might end up more expensive (elevated or utilities needing wholescale relocation) and part cost of the new Old Mangere Bridge NZTA is building for pedestrians (that would and should be a transit mall anyhow).
Rolling stock would come in at $300m (basing the amount of units initially needed and again using the EMU’s on our heavy rail lines as a comparison) and I have added a 10% contingency ($200m) in case of unexpected issues (if we blow the contingency then something is wrong with project management in New Zealand as a whole) giving a total price of $2.5b all up. If you want to take Light Rail all the way to Botany that was another $675m giving a price tag (not including extra rolling stock) $3.175b – still cheaper than City Centre to Mangere at $4 billion and with a larger catchment to boot.

$75m/km for Light Rail?
An associate of mine gave me the price tag of Light Rail coming in at $75m – $200m per kilometre depending on several factors:
- At grade (surface) or elevated
- Reallocation of road space (an issue with Dominion Road but not Airport to Botany given the large grass medians for most of the route)
- Surrounding land use (building a transit line where there is blank land, large grass medians/berms or low density single use zoning (residential) would be cheaper than one through a higher density area more common on the Isthmus
- Utility relocation (major issue down in the City Centre given the Transpower cable on Fanshawe Street)
Airport to Botany (entire line) was theorised in at $75m/km due to large parcels of blank land and the fact Manukau is blessed with large grass medians meaning road reallocation is minimal. Looking at Mangere the wide suburban roads with wide berms are prime for some “upgrades” as well (narrowing to make them more pedestrian friendly) and are not freight routes any more (they were the old State Highway 20 until the motorways were built).
As noted above and if NZTA have their wits about them the new pedestrian bridge to replace the Old Mangere Bridge should incorporate Light Rail under the Build Once, First Time – Every Time mantra keeping costs down from needing to build another bridge for LRT later on (NZTA however, are not doing this and we could end up with another bridge needed).
This leaves State Highway 20A that could drive costs up depending where the Light Rail route goes and if it needed to be elevated for sustained sections of that part of the route.
Completion Dates:
In short for the above Southern Rapid Transit Concept? 2028 for Airport to Manukau and Airport to Onehunga with 2030 getting us to Botany (four years after the Eastern Busway reaches the Metropolitan Centre). The start date would be 2021 one year after Stage 1 of Airport to Botany (as a bus service between Airport and Manukau) is operational.

Summary of costs
Project cost of the Southern Rapid Transit Concept: $2.5b
- $1.5b for the tracks
- $150m for a heavy maintainence depot
- $350m for stations and possible elevating of tracks in certain sections
- $300m for rolling stock
- $200m contingency (not including for rolling stock)
- Extra $675m for extension from Manukau to Botany
Completion dates: 2028 with Botany at 2030

Final note: Costs to extend light rail become cheaper as the placement of the heavy depot and initial rolling stock have already been done. Your main costs in LRT extensions are the tracks, extra rolling stock and every so often a light depot for train storage and light maintenance. Such light depots would be placed in Onehunga and Wynyard Quarter.
Even if the Airport the Manukau section isn’t built initially, it make perfect sense to build the maintenance depot in the area off SH20B and the cost of the short extension from the airport wouldn’t add very much overall to the cost, especially given it would be used when the line runs to Puhinui any way.