The Avondale-Southdown rail corridor is a rather strange aspect of Auckland’s transport system (or possible transport system) in that it has been designated for rail purposes for over 60 years, but has never really got anywhere close to being constructed. It first shows up in the 1946 transport plan for Auckland:
In more recent times the line has been proposed as part of the wider upgrade to Auckland’s rail system that is the preferred option for getting rail to the airport. Last year when the ARC was putting together the background analysis of what major projects should be included in the Regional Land Transport Strategy, the Avondale-Southdown rail line scored quite well in terms of its anticipated patronage. This is shown below: In the final version of the Regional Land Transport Strategy, the railway line is anticipated to be constructed in the 2031-2040 stage of the strategy, although the dates on these later projects are incredibly variable. So while it’s not going to happen any time particularly soon, there will most probably be a day when we eventually construct this line. But, as it doesn’t really go from the CBD to the suburbs like normal railway lines – instead cutting directly across the Auckland isthmus – how could it be made into a line that is useful for passenger rail services? Well I have a couple of service patterns that I could having this line could enable, both of which would be pretty damn useful for Auckland.
The first is shown in the map below, and is effectively a Henderson to Manukau City service, via Auckland Airport. This service pattern is most interesting in that it doesn’t go anywhere near Auckland’s CBD, but as it does pass through Henderson, New Lynn, Onehunga, the Airport and Manukau City Centre I reckon it could be pretty popular: There would be a pretty complicated junction at Onehunga to enable a variety of service patterns, including of course an Airport to CBD train operating via Onehunga and the Southern Line. In terms of this particular line, I think that it’s likely there would be three stations along it (in addition to Onehunga) – most probably near Stoddard Road/Richardson Road intersection, near Dominion Road (a Mt Roskill Station) and near Hillsborough Road (a Hillsborough station).
The second service pattern that you could run along the Avondale-Southdown Line would be a huge isthmus loop, which would incorporate the inner parts of the western and eastern lines. In an ideal world both the western and eastern lines would be four-tracked so that this loop service would stop at all stations while other trains (from further west and east) running along the inner parts of their lines would only have to stop at major stations – saving them significant amounts of time. Having a full isthmus loop would be a great way to tie together the rail system, creating a true network where it was easy to get from anywhere to anywhere along the loop. I think it would help support pretty large-scale intensification at major interchange points along it – helping to reduce our auto-dependency. Here’s a map of where it would go (obviously it assumes the CBD rail tunnel will be built already):
While it seems we’re 20-30 years away from this line being a reality, it’s useful to start thinking about how it might work and what its advantages for passengers might be. In the past I have been a little half-hearted in my support for constructing the line as a priority, and I still do think higher priorities exist elsewhere, but when we do get around to constructing it we will have the opportunity to use the link to help create a true rail network in Auckland. It could be very useful indeed.