Light rail the winner in latest Auckland Transport turnaround

One of the reasons touted for Auckland’s City Rail Link was future rail expansion to the airport but that has now gone out the window.

Auckland Transport’s (AT) board has dumped heavy rail in favour of buses or light rail (trams) for a 40-minute trip to the airport from the CBD, at the same time three Auckland councillors have asked the Auditor-General to investigate the costs and operation of the rail link. 

In a just-released confidential report used to justify dumping heavy rail, AT says light rail will cost a mere $1.2-1.3 billion compared to heavy rail at $2.6-3 billion. There is little detail on buses and no mention of how much they will cost in the report heavily focused on rail.

The council’s transport arm and tge NZ Transport Agency (NZTA) say heavy rail represents low value for money.

AT’s website on the benefits of the city rail loop shows the airport link as one of the reasons it is needed. Although it has been abandoned by AT after a u-turn by NZTA, which was committed to the plan until recently, it could be a decade before routes for buses or light rail are decided.

Auckland Airport wants the route question settled as soon as possible, although AT says the difference between buses and light rail will not have any effect on the airport’s development issues.

Heavy rail would have included tunnelling and an underground station at the airport and AT says its abandonment of heavy rail has removed the problem of the airport company having to hold land for two routes across its precinct while a decision was made on heavy or light rail.

The heavy rail route would have extended the Onehunga branch line by 10.5km with new stations at Mangere Bridge, Mangere Town Centre and then the airport.

Key risks cited were the “low-cost” extension might not have been acceptable to regulators, ground conditions at the airport are a significant cost for tunnelling and the station required beneath the new airport terminal needed building at the same time as the terminal.

The light rail route will extend the proposed Dominion Rd light rail corridor by 14.8km along SH20/ 20A via Onehunga toward the airport with six new stops/stations.

This assumes light rail is already in place but AT is still at the investigation stage and there is no agreement with NZTA or the government over funding.  

The key risks for light rail were cited as shared running with vehicles through village centres meaning there may be unreliable running times. A big part of the alignment falls within the KiwiRail designation to Avondale to Southdown. The ability to accommodate a single track for heavy rail in this sector may limit space for light rail and potentially increase earthwork and structure costs in steep sections. 

If light rail goes ahead, 33 metre long trams will be initially introduced in 2026 and then coupled to form 66 metre two-car trains by 2046. Since plans for light rail were mooted by AT, potential passengers have been sceptical about travel times, although AT says 1200 passengers per hour could be moved in each direction increasing to 2500 by 2046.

AT says the public transport user benefits for the light rail option amount to $1.6 billion and the heavy rail $1.4 billion. This excludes any wider economic benefits. The total estimated capital cost for the light rail option amounts to $1.1 billion and the heavy rail is estimated as $2.3 billion.

In the economic review of the opportunity costs between heavy and light rail, AT’s report says if the savings made between heavy rail’s $2.6 billion cost and light rail’s $1.2 billion are correct, light rail could hypothetically be extended to connect Botany, Manukau and the airport.

If this happened, which is probably unlikely, AT says accessibility to the airport increases significantly, with 21,628 people living within 800 metres of the line extension, which improves access to east Auckland and public transport options for airport employees living in the south.

AT has requested further analysis on reassessing a high capacity bus system taking into account future technologies, such as driverless vehicles. The council's transport arm now wants management to protect a light rail route to the airport “with urgency.” It has also asked for reports considering the costs of light rail compared to buses, route protections and business cases.

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