What to do about the Northern Busway

One of the big unknowns with any potential new harbour crossing is what to do about the Northern Busway.

The first busway services first started in late 2005, before there was a busway, when the Albany and Constellation Stations opened and buses just used shoulder lanes to get to the city. The busway itself opened in February 2008 and usage took off, reaching over 8 million trips annually before COVID struck. At peak times as many 40% of the people crossing the Harbour Bridge did so on a bus. That makes it one of the busiest and most successful PT routes in the country and that success is further amplified by the fact it delayed by decades the need to build another harbour crossing costing tens of billions of dollars. Last year the busway was extended to Albany making it even more useful as services are now faster and more reliable.

While a lot of the focus is on what happens with the harbour crossing itself, just as important is what we do once some form of rail reaches the North Shore. There has been some thinking on this in the consultation released last week and also in previous business case work. This has boiled down to two options, do we convert the busway to rail or build an entirely new route.

A new route

The key justification for talking about a new route is the concern over level of disruption that it would cause while during the conversion process as buses would not be able to have such a direct and easy route. AT officials even describes those concerns as “extreme” in their recent paper to the board about the harbour crossing.

AT specialists have raised extreme concerns about the busway conversion options, given the difficulty of continuing to operate a busy busway whilst relocating significant underground services and laying a new slab with tracks and power supply for light rail. This issue has similarities to the challenges and difficulties currently being experienced with the Rail Network Rebuild.

While I do understand AT’s concern, the two main issues with the mitigation for the Rail Network Rebuild is the current driver shortage and AT’s inability/refusal to add any kind of bus priority to mitigation routes (even when they said they would). But the bus driver shortage won’t last forever and they would have many years to plan for mitigation infrastructure – I’ll cover some options later in this post.

I have heard of concerns from other agencies too but I do find it somewhat ironic that officials are so worried about changes to the busway, especially after many of them argued for decades against rail projects because buses are meant to be so flexible.

One issue that’s not often mentioned is that the busway is also often used by emergency services, especially ambulances accessing North Shore hospital. These would need to move back to the motorway or local roads.

There are some benefits to a new route though. The main thinking is that it would travel to the west of the motorway, likely serving Glenfield and North Harbour as well as potentially a few other local stations. This would provide greater overall capacity as the busway would still be operating and expand the coverage of the Rapid Transit Network, which combined with planning changes in the additional areas served, should see greater ridership.

But this option has problems too, the main one being the cost, back to that AT paper again, they note:

Alignments away from the busway corridor are challenging in terms of the North Shore’s topography and dispersed centres, making it harder to identify a sufficiently populous route to justify the expense of a new tunnel.

Even in a straight line, a corridor from Smales Farm to Albany is over 7.5km and diverting to go via Glenfield would increase that to likely over 9.5km. There are no obvious corridors that such a route could use and combined with the topography it means any such line would likely need to be mostly tunnelled. Based on what we’re seeing with other projects, such as the City Rail Link, Auckland Light Rail and this harbour crossing, that could easily be $10 billion or more. Is that cost and the benefits of a new corridor really worth more than perhaps a year of disruption to the busway?

Converting the Busway

It seems bizarre to me that we would want to choose to run two closely parallel rapid transit lines/services from the North Shore to the city, especially if it’s just to save a bit of disruption. A better use of that money is likely to be using it to supercharge feeder services and other buses serving the western North Shore through both more service provision and better priority.

There’s also the issue of demand. Modelling recently for the Auckland’s Rapid Transit Plan – which seems to largely be being ignored by the likes of the Light Rail project, suggests that in the peak hour in the peak direction, there is about demand for about 13,000 trips across the harbour via PT, a level of demand that is within the capacity of a single light rail line

Interestingly, and perhaps highlighting the absurdity of modelling, it suggested that even if the corridors were mostly parallel, that over 8,000 people would stay on buses with fewer than 5,000 being on Light Rail.

The busway was originally designed geometrically with a conversion to light rail in mind, however that doesn’t mean we can simply slap down some tracks. On the original section between Constellation and Akoranga, Transpower paid for ducts to be laid underneath it to carry 220 kV cables and some of you may recall them disrupting the busway in 2012/13 when they pulled the cables through those ducts. My understanding is this cable would need to be moved if there was ever a project to convert the busway to light rail – but it isn’t an issue on the newer section of busway from Constellation to Albany.

So how could a conversion of the busway work? Here’s my thoughts.

1. One of ATs potential enhancements for the busway includes changing stations to fully separate out local bus movements busway services, instead of the current situation where some local buses use the section of busway through the station as a large roundabout. This would be needed for any rail conversion anyway so should be done in advance of that work.

   

2. Do as much preparatory work as possible. The comments above from AT and others we’ve heard from officials over the years pretend like nothing can be done in advance. Yet there is no good reason why most of the underground services couldn’t be moved in advance of disrupting the busway. Work done in advance could also include things such as setting up any required power substations, getting catenary poles installed and other works that don’t require digging up the busway itself.
3. Have Waka Kotahi prepare in advance by having ready either motorway shoulder bus lanes or even just temporarily converting general lanes.
4. When the time comes, we close the busway and in its place run a ‘mitigation’ network buses – by then we shouldn’t still have bus driver shortages which is the main constraint on the mitigation for the Rail Network Rebuild. This mitigation network would include running express buses from the main interchange stations to the city using those shoulder bus lanes, and a local North Shore replacement for the NX services (e.g. to get from Constellation to Smales Farm) using local roads with bus priority and/or the motorway bus shoulder lanes. Both of these would add a little bit of travel time, but it shouldn’t be significant.
5. A mitigation network would require more buses to operate but one option we could look at for this is simply by simply delaying the retirement some buses by a year or so.

While this would be frustrating, it’s hard to see it being worth billions of dollars to avoid.

Another aspect that could impact how and when the busway is converted is where the harbour crossing goes. One of the reasons we’ve long supported a spur to Takapuna, apart from serving a major town centre, is that provides some stageability. That is, the harbour crossing could be built and up and running before starting on the busway conversion. It means the busway conversion is limited to construction and commissioning of the rail line itself and not any harbour crossing or city centre side infrastructure. That would make the busway section quicker and faster to deliver.

Overall I just can’t see the justification for building an entirely new but largely parallel route through the North Shore over managing a year or so of disruption, especially as the process for doing that could give some good long-term benefits – such as adding bus priority to some arterial routes.

If we’ve got billions to throw around, I’d much rather we focused on other parts of the long planed and often neglected parts of our rapid transit network, like the Northwest, Upper Harbour and the Airport to Botany corridor.

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