Most weekends we dig into the archives. This post by Matt was originally published in March 2019.

It’s been some time since we last heard anything official about the Additional Waitemata Harbour Crossing project but that all changed a few days ago with the NZTA updating the project page for it along with publishing two briefings on it to the Minister of Transport last year. More on them soon but first it’s worth noting they’ve now referring to the project as Additional Waitematā Harbour Connections and the narrative appears to be changing to one that moves away from a focus on route protection of a road crossing and more towards investigating whether it makes sense to build additional crossings of the Waitemata Harbour.

The first briefing is from February 2018 and has quite a traditional NZTA ‘road focused’ feel to it, seeking to push ahead on protecting the route with urgency. What is interesting from it though is that the plan now appears to be a tunnel from Esmonde Rd/Akoranga Station all the way to the Central Motorway Junction. This is to avoid having to do any more reclamation along the foreshore and would mean tunnels about 6km long, almost twice as long as previously planned. However, given the plans would see the existing bridge effectively become ramps only connected to Fanshawe and Cook streets, those from the western North Shore heading past the city would need to use the tunnel and this would likely mean first needing to head north on the motorway to Esmonde or Northcote roads and then doubling back to access the tunnel.

The second of the briefings is far more interesting and is likely responsible for the change in tone of the project. It confirms, with a lot of data, what we have suspected for a long time – that another road crossing is a complete waste of money that either undermines the goals for the city centre or doesn’t actually achieve much. I suspect this is related to the change in purpose noted earlier.

The briefing starts with some of the background information, including historic demands. The graph below is perhaps the most interesting of these, showing what’s happened in car and public transport trips over the past few decades:

It confirms that over a third (11,000) of the 31,000 people travelling over the harbour bridge in the morning peak are doing so on a bus and increased bus use accounts all of the growth in travel over the bridge during the AM peak since the early 1990s. This also confirms that it’s the approaches to the bridge that are the constraint, not the bridge itself. The paper goes on to highlight that of the 31,000 people crossing the bridge in the morning peak, 14,000 are heading to the city centre while the other 17,000 are heading past it. Delving deeper, of the 14,000 to the city, around 6,000 (42%) are travelling by car with 8,000 (58%) on buses. The other 3,000 on public transport were likely travelling via Ponsonby Rd or on a bus that passed through the city, say to Newmarket (these numbers will be from before the new network launched).

The key part of the briefing are the results of some really interesting transport modelling on a variety of crossing options. The modelling seeks to help answer the following questions

  • What if you don’t do anything?
  • What if you just built a light-rail crossing?
  • What if you build both a light-rail and road crossing?
  • What impact does introducing road pricing have on all these options?
  • What impact does widening (or not widening) the northern motorway from Esmonde Road to Constellation Drive have on all these options? It is noted in the briefing that widening the motorway would almost certainly be required.

The graph below shows the current numbers and how they are expected to change over time under the possible different scenarios.

There’s a lot going on in the graph above, but some of the key take-outs for me are:

  • Even if you introduce road pricing, building a road crossing still induces around 6,000-8,000 more morning peak car trips.
  • If you don’t do road pricing, build a road crossing induces around 10,000-15,000 more morning peak car trips
  • Light-rail seems to add around 3,000 morning peak PT trips. This seems quite low and reflects how transport models continue to struggle to simulate public transport capacity issues. It simply isn’t practical that we could more than double the number of buses in the “do nothing” scenario given the constraints on our city streets and that adding that many buses wouldn’t also impact on capacity on the bridge for cars. The NZTA acknowledge this fact in the briefing.
  • Building a road crossing doesn’t seem to reduce light-rail ridership.
  • A future with pricing and light-rail gives the highest “mode share” for public transport – with over half of morning peak trips being made by PT. Even without pricing and a light-rail only crossing you just get over half of trips being made via PT.

The next graph is perhaps the most telling of all, as it compares travel speeds and total vehicle kilometres travelled (VKT) of the different options:

Once again there’s a lot going on here, but let’s focus on the “with pricing” options – given that by the mid-2040s it’s pretty much certain we will have some form of road pricing in place (as a replacement for fuel taxes, if not for anything else). The other thing to remember here is that these vehicle speeds and VKT are across the whole Auckland region, meaning that what looks like relatively small differences between the options are actually likely to be quite noticeable.

  • Of the four scenarios, the best-performing in terms of average speed across the transport network seems to be the “road pricing and light-rail only” option.
  • This is closely followed by the “do everything option”
  • The third best scenario has a road crossing, light-rail and pricing but no widening north of Esmonde Rd

Thinking about this further, I came to the realisation that this is actually a pretty amazing finding – when you compare the first green bar and the third/fourth green bar. Comparing these highlights that basically the roading project does nothing over and above light-rail and road pricing. Those billions of dollars of spend on a massive new motorway tunnel and gigantic widening don’t even speed up traffic at all. In fact it seems that traffic goes slightly slower with the project in place than it does without it. This is not just a project that would have a cost-benefit ratio that struggles to reach 1 (i.e. does it generate enough benefit to justify the investment in it) but rather a cost-benefit ratio that would struggle to reach 0 (does it create any benefit at all?). This is also a point made by the NZTA

The next graph looks at impacts on the city centre, which highlight once again what a disastrous project the road crossing would be:

Looking first at a situation where there is road pricing, the road crossing induces around 3,500 extra car trips into the city at peak times. Without pricing the result is even worse, with the road crossing inducing 3,000-5,000 more peak car trips into the city centre. Not only is there probably nowhere for these cars to go in the city centre, anything that increases car volumes is completely contradictory to what the Council (and I’m guessing the Government) are trying to achieve.

Overall I think this briefing should put the final nail in the coffin of a road crossing of any form. For a long time we have been saying the crossing is too expensive, will create horrible environmental impacts, will ruin the city centre and won’t even fix congestion, and that we should build a light rail only bridge. The fact that including a road crossing actually makes car travel around all of Auckland slower than a “light-rail only plus road pricing” scenario is just staggering. This project will literally makes things worse for the very people it’s aimed at helping. The current investigation is due to be reported back in the middle of the year, it will be very interesting to see the results of this work.

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34 comments

  1. The nats fall into the typical right wing “we know best despite all evidence” category that trump does. How could anyone who has read this report be proposing another harbour road crossing? And also cancel the ability to walk and cycle across!
    Although you do have to question the validity of these reports. It looks like this one was produced when labour were in power, I wonder what the outcome would have been if national were.

    1. I read yesterday that Trump didn’t want science to get in the way of reopening schools. I mean WTF? I don’t think our Nats have quite got to the point of specifically banning reason yet. But who knows what depths of populism their present leader will delve to.

      On the Harbour crossing issue, these reports are the outcome. Every few years NZTA pay a company to dig out the old Opus report, update traffic numbers and costs and change to the latest font and publish it. The reports serve to shut people up and give the impression someone cares. They are great value for money as you can knock out the same old tired report every few years instead of doing anything.

    2. C’mon lefties – give a crusher a break. The article I read referred to a proposed road/rail/PT crossing. Welcome their proposal with open arms. Get stuck in when it becomes more than an election pledge and there’s some detail. I agree, by the way, that feeding more cars into the CBD makes no sense

  2. A senseless idea that is senseless, and economically and socially irresponsible in a globally warming earth. Why give crushing stupidity a break?

  3. I think that a rail crossing would be transformational. If you could cross under the Harbour in a few minutes from Takapuna to the city, that would be quite a game changer for Auckland and take cars off the bridge.
    If we are going to dig a tunnel, may as well dig it big enough for a road as well. Even if it’s just future proofing in case the clip ons crack again.
    I find the 400 million being spent on the Northern Pathway much more a waste of money. What ever happened to Skypath and the 30m solution?

    1. Creating a road and rail crossing would be significantly more expensive than just a rail crossing. A rail crossing would fit in a single 10m diameter tunnel with dual light metro tracks. A road and rail crossing would require a pair of 14m diameter tunnels. So a road and rail crossing would be more than twice as expensive because you have to dig twice as many linear metres of tunnel, plus they’d be wider tunnels. Also it doesn’t make sense for a rail crossing and a road crossing to be on the same alignment.

      1. And you have to vent out all those exhaust fumes too. And you can’t exactly stop the road tunnel at britomart like the rail.

      2. The ventilation requirements and fire suppression measures for a road tunnel are several orders of magnitude greater then those required for an electrified passenger railway.

    2. It isn’t 400 mil is it? And it is more than just skypath. let’s say it takes 5% of the traffic off the bridge (I mean why wouldn’t you cycle if you live in takapuna and work in the city). That $400 mil (if it is that much) could postpone the need for a $5 billion investment for decades. Just like the supposed white elephant northern busway did.

      1. “I mean why wouldn’t you cycle if you live in takapuna and work in the city?”

        Probably for the same reason that most of those living 9 or 10km from the city don’t cycle.
        Looking at the cars on the roads and those in PT I don’t think too many cycle from Pt Chev. Mt Roskill, Ellerslie, St Helliers, and such like.
        Now I don’t have the numbers, but I doubt that cyclists from any of those areas have taken 5% of the traffic off their roads, so why should Takapuna be any different?

    3. “If we are going to dig a tunnel, may as well dig it big enough for a road as well.”

      Who said anything about digging tunnels? The preferred solution is a concrete tube that sits on the bottom of the seabed:

  4. Get it right, the underground rail from Britomart to Mt Eden is a waste of money, a second crossing for the harbor bridge is not a waste of money.

    1. When does more roads and duplication of roads become a waste of money? Maybe we should have 100 lanes crossing the harbour joining up to a 3 lane motorway at each end?

  5. The history of the last few years and the PT policies of the National Party, NZ First and Labour all go to confirm why the existence of Auckland Transport is critical. All three parties are proposing stuff which is ridiculously over the top, and/or which do nothing to create the kind of high-level PT network that we really need.

    We’re seeing a kind of Trumpian rejection of expertise in favour of “what we think will win us the most votes in September”. All those studies that clearly identified the way forward: in the bin because they don’t deliver the “right” result.

    Just be grateful that all the parties are focusing on the RTN and are content not to meddle with the FTN.

    To all those who think that AT should be “reined in” and subjected to a greater level of political control: be careful what you wish for. I for one appreciate that AT stands outside direct political control, and is mandated annually by AC through the LOE/SOI process and the annual budget round. To me, that’s about the right balance.

    1. You must live in central Auckland if you believe that David – everyone who lives in East or North Auckland knows what a disaster AT has been. They are unelected and have no accountability, so all we get are pet projects that favour their preferred parts of Auckland.

      1. Speaking from an East Auckland perspective they’ve definitely been an improvement on the old car centred Manukau City Council, still not great but an improvement.

      2. I live in North Auckland and my transport improvements have been exceptional since AT was formed. The new bus routes and the frequent connections to the busway are phenomenal. I had actually moved away from the North Shore because the transport was so bad, but moved back because of the huge improvements.

  6. I would perfer the crossing goes from esmond>bayswater>stanley bay>judges bay SH16….navy base could be a problem though…

  7. So in summary these are the facts?
    *Bridges are less costly than tunnels on a per metre basis.
    *A new Auckland harbour bridge for light rail and for walkers/cyclists would be shorter than a tunnel for motor vehicles.
    *Therefore the PT/Active mode bridge option is much less costly than the motor vehicle tunnel option.
    *The capacity constraint for motor vehicles on SH1 is not the existing harbour bridge but the entire length of SH1 before and after the bridge so adding a new tunnel does not increase the capacity of SH1.
    *A bridge could add aesthetic value to the view of Auckland’s Waitemata harbour and for those travelling across the new harbour bridge they would experience one of the most attractive harbour views in the world. A tunnel forgoes these benefits.

      1. Although I would say there are more important places to spend money right now. The north shore already has some of the best PT in NZ.

        1. Dear JimboJones.
          The only person who whould say that “north shore already has some of the best PT in NZ” would have to be part of top mangagement in Auckland Transport or a brain washed worker. I found it a money waster in placesm nobody wants to fix it.

  8. And while the politicians discuss this again, access remains denied, inequitably, to people on foot and bike.

    What we need to do is reallocate lanes to walking and cycling now. If this worsens congestion on the bridge and slows the buses down, we then should reallocate lanes to buses. In total, the capacity of the existing bridge will be divided up differently, to those modes that are more space efficient, so people flow will be better.

    Just as adding road capacity across the harbour worsens congestion in the network, reducing road capacity across the harbour through lane reallocation will ease congestion in the network. Which will aid all sorts of other projects. Plenty of “network optimising” signal phasing changes that disadvantage people walking and “congestion easing” intersection widening projects that just add danger won’t be required, saving us heaps of money (and saving us from these destructive projects at the same time.)

    1. Re active transport bridge lane, there must be few road cones available now that huntly bypass is completed. Sunday’s first. Ciclovia takapuna to britomart.

  9. Why would you increase the flow rate at the highest flow rate area.
    The bridge has more lanes then the motorway, the reason traffic backs up is not the bridge, its first and foremost the speed limit change, 100-80. Then the issue processes to stop and start traffic as everyone converges onto the same bridge within an hour of eachother.

    You need to be diverting traffic from high density residential areas like East Coast Bays, more importantly Devenport that has everyone using a single road in and out.

  10. For goodness sake work it out with mathematics, the short length of the bridge, going from 80 to 100km/h you do not save many seconds with the trip on the bridge.
    But maybe statistics might show the slower speed at 80km/h if that reduces accidents, and it is the accidents and immediate post-accidents that waste all the time.
    It is the handicap motorists, that think they are the only people on the busy roads that needs to be looked at, they are a dime a dozen.

    Not only that if Auckland Transport (AT) fixed up the bus service more people would use the bus service, and if AT went to the people with public meetings and asked “What would make you use the buses instead of using a one person car every day?” maybe that might be a better solution than a wasted rant on both sides of the argument.

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