Rail Across the Waitematā: some thoughts

The North Shore Line, The Northern Line, Te Raki Tereina…

NZTA in a recently released report showed that there is some urgency in starting work to replace the Northern Busway with a higher capacity rail system on a new crossing. This is because:

1. Demand to access the city centre from the Shore is on a sustained growth path with ongoing growth on both sides of the harbour.
2. Only increased Rapid Transit can meet that demand, no more cars can be squeezed onto city streets and carparks.
3. Nor can North Shore local roads comfortably accommodate feeding a substantially bigger motorway.
4. Critically the number buses required at peaks in the city centre is fast becoming unworkable.
5. The Busway itself will be overcapacity by the mid 2030s at the latest.
6. A direct Rapid Transit crossing will also increase the attractiveness of that option.
7. Will free up capacity on the bridge, along with remove the bulk of the buses, this will improve the existing road crossing.
8. And a new crossing on a separate mode will add resilience to city networks.
9. A higher quality higher capacity alternative crossing will also more easily enable other volume control measures such as pricing to be added, to keep the traffic lanes efficient for high value service and delivery vehicles.

City Centre access in the morning peak across the harbour has only been possible because of the Northern Busway. Essentially it is now becoming a victim of its own success. NZTA’s Traffic modelling shows adding more traffic lanes is counterproductive in its effects on the wider city’s road networks alone: it would make traffic worse. This is without even considering all the other negative outcomes of increasing traffic volumes economically, environmentally, and in public health, safety, and wellbeing. And of course the enormous cost. Replacing the busway with a high capacity rail system on a new crossing is therefore likely the most cost effective and efficient option for enabling growth in access between the North Shore and the wider city.

The Northern Busway has been one long success story, and a credit to all those who toughed out its delivery in the face of huge resistance (from the usual quarters). The extension to Albany currently underway will only accelerate this growth. And, as an aside, the Eastern Busway is certain to follow the same arc, as it is entering a market with no current Rapid Transit, like the NB did, with resultant high traffic congestion and auto dependency, so the pressure it will add to Panmure Station is likely to be severe. Which reminds us:

It’s all about the Network

As with any route planning it must always take place with an understanding of the whole network. It is essential to put this situation into the context of the multi decade programme of retro-fitting a city wide Rapid Transit Network to Auckland, to complement its extensive road one. Below is a recent version of this constantly evolving plan from an ATAP report in 2018.

Although projects get announced and built separately, the big prize is a complete whole network, like most cities ours will be made up of various but interconnected systems. We have about a third of it in operation already, in red in the map below, yellow indicates the extensions currently underway, blue in planning, and white, well, in further planning, including a future harbour crossing…

We expect the Puhinui link, the 3rd main, and electrification to Pukekohe to shortly move from blue to yellow. Which hopefully will mean funded and underway will this year be:

1. City Rail Link
2. Northern Busway extension
3. Eastern Busway
4. Puhinui Link and Interchange
5. 3rd Main
6. Electrification to Pukekohe

Which is a fantastic list. A sign that ATAP, the Regional Fuel Tax, and our local and central systems are working pretty solidly on this plan. Add to this the additional trains currently being built too.

So about 1/3 done, a 1/3 underway, and 1/3 future.

Just considering the Rapid Transit level, there will still be a lot of buses supporting this network everywhere, each point of the compass will have a Rapid Transit spine:

• East via Eastern Line and Bus (The Eastern Busway connecting to rail at Panmure)
• South via Southern Line
• SouthWest via Mangere Light Rail, and the Southern and Onehunga Lines (through transfers at Ōtāhuhu and Puhinui Stations)
• Isthmus via Dominion Rd Light Rail
• West via Western Line
• NorthWest via NW Light Rail
• North, currently served by the Northern Busway and Ferries.

Of course we need to improve the ferry services, but even under the most ambitious scenario ferry services cannot meet a meaningful amount of future demand, because, by definition, even with the best wharf connections, they have a structurally limited water edge catchment. So why not just keep adding buses? Well of course we are, the Northern Busway is getting extended right now, which will make it boom even more than it has been. As it is every year more services have needed to be added. There is some future capacity in the Busway, we can make a couple of bridge lanes full bus only, reduce general traffic lanes down to one each way on Fanshawe St, and turn it into a massive bus corridor. But even doing these things, which I assume we’ll have to before a new crossing is built anyway, will just increase bus congestion in the city, to the point of (expensive) operational inefficiency and frustration for users.

As ever, and as the NZTA report confirms, what we build or don’t build shapes what we do and what kind of place our city becomes. If we want ever more buses then build for them, if we think that trying to cram more cars into the city and the Central Motorway Junction is a great way forward, or even spatially possible, add a traffic crossing. But if we would prefer to have more people travelling by electric rail; then we’ll have to supply that. Whatever we feed, in a thriving city, will grow. And that is especially evident over a naturally constrained corridor like the harbour.

After the CRL and the two LR lines are complete adding the conversion of the Northern Busway to rail will mean there will no longer be a major branch Rapid Transit Network delivering buses into the city centre. There will still be a lot of buses on city streets, but no major point of the compass generating the very high volumes that a rapid transit line generates. So manageable volumes, rather than impossible ones. This leaves to ask:

What type of train and on what city route?

There are two likely broad route options:

1. Underground from a station at Wynyard Quarter, continuing below Wellesley St to platforms below the south end of Aotea Station (with possible future potential to extend).
2. Connecting to the coming Light Rail system probably at surface level at Wynyard Quarter (as indicated on the Network map above).

And roughly three options for system:

1. Our existing system (route 1)
2. Extend the coming light rail system (route 1 or 2)
3. Add a third system (route 1)

As ever there are trade-offs to be made.

Route 1: Considerably more expensive to build because it requires a city side tunnel, but offers high capacity, and the opportunity to introduce a driverless system as the whole route will be grade separate, which means operating cost savings and very high frequencies. Potential for a future extension across the city (a CRL 2) in an east west direction, but at even further considerable cost. Could be Light Metro or our current system. Light Metro would offer considerable cost savings both in construction and operations, and is more likely in my view. The only plausible reason for using current system would if there was an intention to connect to the existing network say at Parnell (as I imagined here in 2012) through the cost and complexities of this I think count it out.

Route 2: Would be considerably cheaper and quicker to build across the harbour and on the busway, and avoids any city tunnelling, at least for a decade or more. And by linking into existing lines immediately offers a through routed service, with one seat rides up Queen St to Mangere and the North West. Albany direct to Airport service for example. But would at some point probably hit capacity limits.

Both options have appeal. A key consideration is closer analysis of the capacity of the Light Rail option, which we will look at in a future post, as well as ways of using this as a means of staging the project over time: Connecting to the coming surface system first and then years later adding an east west tunnel to complement it for destinations beyond the city, which appeals on cost and speed grounds.

This post is intended as an introduction to this issue, despite its length, as there is a great deal of detail to consider. For now, in summary:

The good news…

The Northern Busway is great, but will need superseding.

Auckland’s Rapid Transit Network is currently growing in more directions it may appear.

There are great options for a new RT harbour crossing.

discus…

The post Rail Across the Waitematā: some thoughts appeared first on Greater Auckland.