This post was first published at TraNZport blog and is republished with permission.
This is a follow-up to my previous post on a rapid transit start-up proposal for Christchurch. If you haven’t read that, it might be a good idea to do so before reading further on this one.
I wanted to follow up on what I proposed with a bit of a more in-depth “Q and A” style piece on some aspects of it, hopefully giving a better illustration on why I proposed what I did. As a reminder, here is what I actually proposed:
So. Why heavy rail?
One of the lessons that Auckland’s transport experience over the last 30-40 years tells us is how not to do things. During the 1980s and 1990s various light rail and bus rapid transit schemes were proposed, often getting bogged down in arguments over mode choice, with new technologies being promoted that hadn’t seen much application, in this case being O-Bahn “guided busway” technology. Sound familiar? **cough** trackless trams **cough**.
There were lots of complications associated with implementing light rail, which eventually won the debate against a guided busway, mostly related to form and function, and cost, and this caused further delay during the 1990s. In the meantime, Auckland’s decrepit commuter rail network was kept going as an interim measure, perhaps in part to keep the network intact in case it was needed for an eventual tram-train network. The purchase of diesel multiple units from Perth, and some upgrades to stations caused an increase in use, which led to the idea to extend the railway further into the city at Britomart, completed in 2003. Britomart was designed for conversion to light rail/tram-train operation, but the incremental improvements to the rail network and services led to exponential growth in patronage, which led to electrification, and other network improvements, culminating in the City Rail Link.
As I explained in my post, the cost of introducing light rail or bus rapid transit along the proposed rapid transit routes in Christchurch would likely run into the billions. Wellington’s proposed rapid transit line is costed at approximately $2.2 billion for about 10km for both stages. The sections of rapid transit with dedicated right of way in the Canterbury Regional Public Transport Plan, released by ECan in late 2018, amount to a length of approximately 20km between Belfast and Hornby. It’s easy to see where the maths goes on this one, and having or not having rails included won’t make a lot of difference as the road space will require serious reworking, and property purchases wouldn’t be out of the question in places.
Unfortunately, since commuter rail ended in 1976, much of the former infrastructure has been impacted by subsequent development that was done without any thought to its potential re-use. Still, enough exists to create a workable start-up network along the main northern and southwestern corridors, and like Auckland, this could be the start that rapid transit needs, trialling the impact and demand to inform future investment decisions. Better yet, it doesn’t preclude changes in thought on mode. Light rail or bus rapid transit could be developed in future, either supplementing or succeeding heavy rail, and the start-up proposal provides a pathway for this to happen with an initial short BRT section that would, in the interim, be used to link the rail lines to the Central City.
What about cost?
This is really why, to me, this proposal, or one like it, is a “no-brainer”. By using the existing railway lines, huge costs savings are made as the dedicated corridor is already there. In my previous post, I estimated it would cost approximately $300-$400 million to implement what I proposed. ECan’s report for a temporary rail service between Rangiora and the city was priced at $8.2 million for capital costs . That might be a tad on the “too cheap to be true” side, but the new Hamilton to Auckland commuter rail service is costing $78.2 million for a five year trial.
Where will the money come from?
First, the government has already offered to chip in $100 million to getting commuter rail up and running in Christchurch (initially Rolleston). That’s possibly a third to a quarter the way there already. Unfortunately, local authorities are not beating down the government’s door to get their hands on it. For the new Hamilton service, $68.4 million of the cost is being provided by NZTA, with the remaining $9.8 million coming from local authorities. That’s a deal, so if greater Christchurch local authorities went to government with a proposal like mine, it wouldn’t be unexpected to get a similar deal.
What about the bus rapid transit section?
This is probably the part I didn’t go into near enough detail on. This BRT line would connect the two lines into the city centre using a mixture of full-time bus lanes and segregated bus corridor. I would envision it travelling from a station near the Riccarton Rd railway crossing, along Riccarton Ave and Tuam St to the Bus Interchange, then down Manchester St to a station on Moorhouse Ave.
A dedicated service with high capacity buses could operate along the length of the line and onwards, perhaps to the university campus at Ilam, or the airport. Additionally, existing (and future, as per the latest RPTP proposals) bus services can make use of the infrastructure.
The purpose of the bus line is that it would be a win-win for CCC. Integrated with the rail lines, you get a rapid transit network to the inner suburban nodes, the outer suburban nodes, and major satellite centres, within a fraction of the time and cost as a larger BRT or light rail corridor developed from scratch.
Here is a map of what I propose at a high level, drawn rather crudely and in a hurry (apologies!):
Does the proposal allow for intensification?
One of the key outcomes of the RPTP was that it would drive intensification at key nodes and activity centres. The rapid transit corridors in the RPTP seem to be acting on the assumption that key areas for intensification need to be linked with one, purpose built, rapid transit line.
My proposal allows for intensification roughly along the same corridor, but does so using two different mode (rail and BRT). This grants the benefits of ease of implementation and cost that the rail corridors allow, while the “City Line” BRT improves bus connections along Riccarton Rd, and integrates with rail to create a cohesive rapid transit network. In short, yes, this proposal allows for the same outcomes the RPTP seeks.
Does this proposal “lock-in” heavy rail for these corridors?
No. That’s one of the other strong points of this proposal, as it is a start-up/gateway/trial rapid transit system (precisely because it utilises the existing rail corridors rather than building new, dedicated ones). This allows, at key decision making points along the process, reconsideration of mode, route, and overall application.
It may be that heavy rail continues to be invested in, the corridors improved, extended, or whatever the case may be (just like Auckland). However, it could also be that at some point another path becomes more attractive, such as utilising a different mode. That’s the strength of using the rail corridors and taking an incremental approach; a different path could be chosen (or not) once the broader concept has time to be suitably trialled and there is greater political and economic capital to invest further. I foresee something along the lines of the below as the decision making process this proposal allows:
What would it look like, “day to day”?
A key decision, which would impact upon costs, is what to build or acquire, where, and to what level (i.e. something small, temporary, or something large and permanent), and the service levels.
First, in terms of service levels, my default position is something like 30 mins throughout the day, with 20 minute services at peak on the rail lines (similar to current service frequency on the Blue and Yellow bus lines), and 10 minutes throughout the day (plus more services at peak) on the BRT. However, that’s something that, as far as this proposal is concerned, is pretty flexible.
However, service level will undoubtedly have an impact on infrastructure. This is particularly true for the northern line as it is largely single track, and some expenditure on passing loops and/or double-tracking will be needed to allow the service frequencies desired. Signalling upgrades might also be needed, to ensure those service frequencies can work, especially amongst regular KiwiRail services.
In terms of rolling stock, there are a few options, including reusing former Auckland rolling stock (if available), however I also think it’s desirable to purchase something new. There are some good options out there which could be adapted to the New Zealand loading and rail gauges, including some powered by hydrogen (though whether we have the infrastructure to cost-effectively support that might be worth further investigation). In the end, it’s not the role of my proposal to look too deeply into this, but what it can do is indicate that trains probably don’t need to be too big (maybe two car units similar in size to Wellington’s) and about 12-15 would be sufficient to operate what I propose above. Shorter trains mean smaller stations, and these can be extended in future if required (again, following Auckland’s lead).

The BRT could utilise double deck buses (like in Auckland) or articulated buses could be used, that allow for faster boarding and are more suited to short distances (although that might require dedicated infrastructure at the bus interchange).
What else could be considered?
This proposal is merely a demonstration of how the issue of a cost-effectively developing rapid transit in Christchurch could be implemented, this is not presented as a “be all and end all”. There is flexibility within it, and there are alternative approaches. Here are a few, which could save further money and bring the project forward:
- Introduce Riccarton to Rangiora as a first stage, with BRT only as far as the bus interchange
- Introduce peak-hour services only as a start, cutting back on rolling stock and operational costs
- Preface the introduction of this proposal with improved buses (dedicated express buses) along completed motorway (perhaps by expanding shoulders to create bus priority lanes), and expanding bus priority measures in the inner city
- Combine elements of any or all of the above.
Where to from “there”?
A question I’ve been asked is where would things go beyond what I proposed? I’ve already touched on the flexibility that this proposal provides, but I suppose it is worth exploring, briefly, what it could lead to. First, I think it would be logical to look at how the BRT might be extended, especially to the west towards the university campus and airport. Additionally, if successful, I think an extension of rail into the central city could be looked at, which could be heavy rail or a switch to another mode.
The extension of the BRT towards Belfast and Hornby is an interesting one (as is conversion to light rail). It seems to go against the grain of what I am suggesting, but given that heavy rail is a trial and/or gateway to implementing a rapid transit network, it’s possible investing in a dedicated corridor along more favourable lines for development might be desirable (remember, CCC contains over three-quarters of greater Christchurch’s population, so they will ask what is in it for them/their ratepayers). However, what could be interesting is exploring working towards two systems for the rapid transit corridors, one express and regionally focused, the other focused on the more densely populated metro area. In effect, you’d end up with a U-Bahn/S-Bhan or RER/Metro type situation. That’s a pretty cool vision.