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How to Explain our Rail Capacity Constraints

Peter’s post the other day highlighting the capacity of the rail network and why we need the CRL got me thinking that about how this critical piece of information is not only missing from Auckland transports marketing of the project but just how hard it is to get that message across to the general public. Part of the problem I find is that people don’t understand how the rail network can be at capacity given how many people it could potentially move so to explain the capacity issue to people you either need to talk to people about it in person or get people to read a few paragraphs about it. Both of those are difficult to do when there are so many people that need to be communicated to for a project like this and the waters also get muddied by electrification and the extra capacity that will deliver.

So how do we solve this, one thing I have been thinking about is a graph to show the capacity constraint that exists today and how it would be affected in the future by the various projects. These numbers won’t be 100% right but do give an indication as to the kind of capacity constraints we will have. The blue line is the rough capacity of the rail network at peak times in the peak direction while the red line is the number of trips using the network in the AM peak, the future AM peak numbers come from some of the work done for the CRL business case.

The first step in the blue line represents the change in capacity with electrification while the second step is the capacity of the network once the CRL is built, in reality that wouldn’t all come on stream straight away as it would depend on how many trains we had. It is also worth pointing out that some of those shown in the red line will be in the counter peak direction. While some of the numbers in here might need tweaking, the real general trend of the graph is what we are expecting to see and the point of this post is to show a different and perhaps easier way of explaining the capacity problem.

Are there other ways that people can think of that would be useful for AT to use to help to easily explain why the CRL is needed?

10 comments to How to Explain our Rail Capacity Constraints

  • Matt, its all very well to expound the virtues of the CRL here on this blog site but I doubt that many people visit the site so your message and that of others supporting the building of the CRL, is not reaching the wider public in Auckland.

    Suggest thus that a website be set up that promotes the CRL and explains clearly to the public at large why it is needed. AC / AT will never get around to doing a proper information campaign and by the time they do, it will be far too late.

    The website needs to look slick in terms of imagery and content layout. Im sure there will be a talented web designer or two amongst those active on the AKL Transport Blog site. If not, a good friend of mine who is a long time PT activist, is a highly experienced web designer who has done a number of major commercial websites over fhe years and who would more than likely be prepared to set up and manage such a site for little or no cost.

    • Matt L

      We are getting more and more people visiting the site all of the time (we have had over 81k views so far in April). I think that AC/AT can do a proper info campaign but they just need to want to and any push really needs to come from them and what I am trying to do is come up with some ways that can help them do that.

  • Peter

    Does this graph suggest that in 2040 we’ll have maxed out the capacity provided by CRL and need to seriously consider other ways of boosting capacity to the CBD, like North Shore rail linking to a realigned southern line?

  • Greg N

    Hi Matt,
    Some suggestions to improve the graph for “ease of interpretation”:
    1. Rename the red line from “AM Peak Patronage” to “AM Peak Demand”, as this aligns the two data plots better in most people sminds as Demand a capacity are self-explanatory.
    2. Rename the blue line to “Peak capacity (with CRL)”.
    3. Add third line on this which mirrors the blue line to the post EMU part (before the upturn for the CRL) labelled “Peak capacity (NO CRL)” that shows the capacity if no CRL is done, as that will show in a glance that without the CRL demand will exceed capacity by about 2025 by my estimation using your red line (which technically won’t have any uptick after 201 when the CRL comes online but thats a minor issue).

    The last thing is to point out to people that you have to size capacity for the peak demand, not the average demand (just like you do on roads), so you build 4 lanes of motorway to cope with the AM/PM peak even if the lanes are way under utilised the rest of the time.
    Then with that simple graph you can show that the current “do minimum” which consists solely of getting new EMUs runs out of steam by 2025, with the CRL added, then we push it out to 2038.
    At a glance we can say that adding CRL now, gives us 15 more years of capacity, for $2b in 2012 dollars, which will be worth a whole lot more $ in 2038 $ you can be sure.

    That way its obvious at a glance that the CRL is not something we can defer, especially when you say, that the CRL is need to start now in order to be completed by 2022.

    • James B

      Good suggestions. But I would suggest that maybe you call the blue line peak supply. That way it becomes obvious that we are talking of a supply and demand situation which is easier to understand in terms of economics.

  • Mr Plod

    Matt, your argument is essentially that without investing ahead of the curve you have no curve, just maxxed out (pun intended) capacity or supply or whatever you want to call it. What needs to be demonstarted is that CRL is the BEST way to invest so the graph needs to be expanded to full passenger numbers all transport modes – a bit of work there but without it the counter argument is always that the analysis is too narrow for a decision on that much investment. dditionally, I like the idea of a website. Might embarrass TA into doing something. Keep up the good work.

  • Publius

    I guess a start would be to add more detail to the existing wiki page:

    http://en.wikipedia.org/wiki/Auckland_city_centre_rail_tunnel

  • Richard D

    I agree that adding to the wiki page is probably a better way of disseminating the information than just adding info here.

    The diagram needs to explain what he step changes are. The typical traveller’s response to lack of capacity would be to say run more frequent trains and or run longer trains. In order to inform the general public of the need for infrastructure change, there shouuld also be an explanation of the limits to those options and where they take the network to in terms of the graph.

  • The more I look at that graph the more I find it less than likely to be accurate. Not that I am criticising Matt’s graph building skills but rather the data that forms the basis for the red line. The red or ‘demand’ line is the one based on projections from various documents about the CRL. There are two points that I find especially hard to believe:

    1. The line appears to dip down in 2016, why? This is the year when all of the EMUs are supposed to be in service, so any disruptions from their introduction will be over. The coming changes to the bus network and its connection to the rail system along with fare integration will be implemented. Surely this is the very point that we could reasonably expect growth to pick up, perhaps steeply, especially as there will be the new capacity from all those lovely new shiny EMUs. It seems far more likely that the network will hit capacity constraints way earlier than 2021.

    2. Then there is the jump in 2021, this is because of the [hopeful] opening of the CRL. But this is a pretty modest bump of about 5000 new riders, or a 20% increase. Is the CRL really likely to cause such a small improvement in the usefulness of the whole network? Let’s remember what happened in Perth after the similar project there, tripling over the next four years:

    And what will the ‘push’ factors be like in 2021? Petrol price, population rise? I have not seen the methodology behind these projections but they seem curiously pessimistic about the effects that the coming changes will bring.

  • mr Plod

    Plubius, Wikipedia is nice and informative. We need sexy, nice CGI flyovers, bring that table of time comparisons (an earlier post) to life with side by side images of one person still sitting on a train while the other sits in a cafe sipping lattes. It’s going to take some time & effort, though surely there are some graphic design wizard PT users out there who could start a wiki style sexy site. Look what the ride the bridge guys have managed to achieve. If it got enough tracton (maybe by people guilding the lilly ever so slightly) the anti lobby would be forced into detraction mode and as they say any publicity is good publicity and currently we have none.

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