Recently I wrote a post about the feasibility of a cross-isthmus light rail line. This is shown in red in the map below and essentially extends the light-rail that is proposed along State Highway 20 between Mt Roskill and Onehunga further west towards Avondale. My previous post highlighted that the line:
- Solved PT accessibility issues for westies who work in the Penrose/Onehunga, Airport and Southern employment zones by drastically slashing travel times. A peak time trip from Avondale to the Airport Airport would go from 1 hour to under 25 minutes while a trip from Avondale to Onehunga would go from around 35 minutes to less than 15;
- Freed up streets like Mt Albert Rd to have a larger cycling rather than PT infrastructure focus;
- Was relatively low cost heavily utilising proposed infrastructure, as well as cheap greenfield or protected corridor making it competitive with a Bus Rapid Transit option;
- Stitched up the network with the Western New Network, Southern Line, Southwestern-Airport Line, Western Line as well as many other bus services like Sandringham Rd;
- Provided crosstown capacity taking pressure off the CRL in the future;
- Did not create severance nor does hinder placemaking due to the ability to use green tracks;
Alternative Route Discussion
I had a lot of discussion with people after the original post about how we could improve the route alignment of the line, especially around stage two where the importance of connecting to New Lynn (the hub of the western public transport network) is paramount.
This led to two major questions
- What is the best route to take from Avondale to New Lynn;
- How best to cross the western line.
Alignment to New Lynn
There were three major options, with me preferring option one:
Option 1: Avondale to New Lynn via Racecourse and Delta Avenue
This option crosses the western line then continues through the Avondale Racecourse and over the Whau River to Delta Ave terminating on Memorial Drive close to the Town Centre, LynnMall, and New Lynn Bus/Train interchange.
You would likely add stations between New Lynn and Avondale at Delta Ave and the Racecourse the latter having the potential to be a large transit-oriented development opportunity.
- After crossing the Western Line the line is relatively affordable which much of the route passing through Avondale Racecourse thus able to use green tracks;
- Opens up an enormous opportunity for transit-oriented development along the corridor including but not limited to a complete urban transformation of the scarcely used Avondale Racecourse;
- Serves the current development happening on the edge of the racecourse;
- Doesn’t interfere with major bus routes and serves new areas not served by major bus routes;
- Re-development opportunity means the potential to use land uplift to help pay for stage two.
- Crossing the western line will be costly;
- Potentially adds to cost of stage 1 if route requires access via New North Road and Crayford St rather than cheaper western line alignment;
Option 2: Avondale to New Lynn via Great North Road
This was the base case alignment from the original proposal after crossing the western line would follow Great North Rd and then down Memorial Dr connecting with the Town Centre, LynnMall, and New Lynn Bus/Train interchange with a station between Avondale and New Lynn.
- Existing corridor;
- Low run long catchment compared to other options as already served by frequent buses;
- Interferes with major bus routes;
- Needs to cross western line;
Option 3: Avondale to New Lynn via Western Line, St Georges Rd and Wolverton St
This option allows access to New Lynn without having to cross the Western line, the route follows the western line until St Georges Rd where it leaves the western line alignment until Wolverton St after which it continues down Wolverton and Clark to New Lynn Bus/Rail interchange.
You would likely add at least a station on St Georges Rd and depending on potential patronage trade-offs one near Portage Rd.
- Doesn’t require crossing western line;
- Serves area south of New Lynn; which is highly zoned.
- Does interfere with some bus routes though not as frequent as option 2;
- Does have some catchment overlap with buses;
- Street works on St Georges and Wolverton may be expensive;
- Less direct.
In the end, option one was my prefered alignment with option two second and option three last. This was because option one has the potential to deliver transformative change for the Avondale – New Lynn area.
Crossing the Western Line
Options one and two both require a crossing of the western line. Since option one was my preferred alignment I also had a long debate on how best to cross the western line with people with two options discussed and me leaning towards option two.
Option 1: Heavy Rail Under
This option would lower the western line with a new trenched Avondale station while also removing all three level crossings at St Judes, Chalmers, and St Georges. This means that the light rail line would be able to use the rail corridor as originally proposed then cross the western line at grade to Crayford West then from there being able to follow the proposed alignment above.
- Removes three level crossings;
- New upgraded Avondale station;
- Will likely result in a number of block of lines;
Option 2: Light Rail Over
Instead of following the western line to the Avondale – Southdown alignment this option would follow New North Rd instead with an elevated light rail station above the current Avondale train station. The line would then come back to grade after the station.
- Likely to be cheaper overall;
- Less block of lines to the western line;
- Will make grade separation of level crossings even more difficult and St Judes, Chalmers, and St Georges would likely be simply closed;
- Makes stage one more expensive as require more street works instead of simple rail corridor works;
- Interferes with New North Rd buses;
Crossing the western line will be a difficult but not an insurmountable issue, the irony is never lost on me that the street where the issues are is aptly named Saint Judes, who of course is the patron saint of desperate cases and lost causes!
An alignment using the old racecourse is my preferred option overall as the alignment opens up a fantastic opportunity for urban development. Given we know Phil Twyford has had officials looking for major brownfield & greenfield redevelopment sites suitable for master-planned Kiwibuild developments in Auckland, and that he is keen to integrate development with rapid transit, this seems like a win-win situation.