Auckland Transport Accord Demonstrates Need for Third Main NOW

Increased trains on Southern Line raises congestion fears


If you live near the Southern (rail) Line like I do you might have noticed an increased amount of both passenger and freight trains plying the two tracks Sunday-Saturday. When I use to work for Transdev (then Veolia) back in 2010-2011 the Port of Tauranga Metro Port freight train services were about 12 (so six each way) a day Monday to Friday and the odd few on the weekend. Passenger Trains (then the diesels) were half hourly in the off-peak and weekends (then including the Eastern Line as well). Fast forward to 2016 and we are looking at 18 Metro Ports a day with that increasing to 24 Monday to Friday and at least six on a Saturday and Sunday depending on what ships are at Tauranga. Passenger trains are stepping up to at least 15 minute frequencies all day, seven days a week outside a peak from next year.


Well while a good one to have given the demand driving increased freight and passenger service the problem of congestion occurs which threaten the viability of the Southern Line. Congestion mean delays and further knock on consequences when things go wrong. Given the Southern Line forms a critical passenger and freight spine in Southern Auckland and linking to the Waikato and the Isthmus extra capacity will need to be built to handle the ever-increasing loads.


Enter the third (and later fourth) main from Westfield Junction to Papakura designed to specifically handle the freight trains keeping them off the same track or tracks the passenger trains would use. The third main gives that extra capacity as well as redundancy capacity on a critical piece of infrastructure if we are to keep on top of congestion on the road network.

The Auckland Transport Alignment Program realises this and has set out through until 2042 when the third and fourth mains are likely to be built. The catch is unlike roads which seemed to be fast tracked under this provincial-thinking Government the roll out of the Third Main is over a thirty year period rather than going all out now. That being rather than sinking money into the Roads of National Significance and the East-West Link which will only make congestion worse (induced demand) that same resource sunk into those ponzi schemes could be sunk into rail now with the third main through to Papakura completed by 2023 (the same time the City Rail Link opens) and the fourth main by 2035.

Remember one Metro Port train with 50 wagons can take between 50-100 trucks off the roads while a single EMU-3 car set can take 288 cars off the road as well. Trucks and cars removed that allow space for those who need to get around such as trades and emergency services.


atap-major-transport-projects-by-decade-map Source:


The Third Main is also going to be needed when we get the Manukau South Rail Link built allowing direct services from Pukekohe and Papakura to Manukau City Centre, and if we do decide to build the Airport Line from Otahuhu which is having a third rail platform being put in.

As for a third main from Papakura to Pukekohe? At least it has been acknowledged as needed in the third decade. Probably the right time but we should build it first before the decade two project of a Pukekohe expressway first.




EMU savings


2 thoughts on “Auckland Transport Accord Demonstrates Need for Third Main NOW

  1. Where possible they should build the 4th now since the cost differences between adding a 3rd vs 3rd+4th are for the most part minimal to do at the same time compared to doing them separately later (and minimise the costs associated with disruption – hard to construct a line when in a confined space with very busy active lines in the future. Quite different to building multiple motorway lanes which cost a lot to build and maintain – an extra rail line beside others would have minimal maintenance costs by comparison). Sure where a bridge or whatever is needed that would be costly to do for a 4th then that piece can be left as just a 3rd for now.

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