Introduction

If you’ve been reading TransportBlog for a while, then you may have noticed that the term “dwell-times” crops up relatively frequently. The term describes the average time that trains are stopped at stations. In several previous posts, we’ve discussed how average dwell-times on Auckland’s new electric trains are approximately 50-60 seconds per stop. In contrast, best-practice dwell-times on rail systems overseas are in the order of 20-30 seconds per stop, so 20 – 40 seconds faster than ours.

In this recent post, I suggested something “had to be done” to shorten dwell-times, to which one commenter (quite reasonably) asked “why“. I was surprised by their question, because to me the benefits of reducing travel-times by 30 seconds per stop seemed obvious. It means that we take Auckland’s trains out of the steam age and into the electric age.

Upon reflection, however, I realised that it wasn’t immediately obvious how apparently small delays of 30 seconds per stop would incur economic costs that warranted action. This realisation motivated me to write this post, in which I attempt to estimate some of the economic benefits of shorter dwell-times on Auckland’s train.

Note that this post does not consider how we might go about reducing dwell-times, and I’d like to ask people who comment not to de-rail the post with such technical matters. The point I’m trying to convey, and which I am interested in discussing, is the economic benefits that flow from running trains faster. Similar arguments apply to efforts to close small intermediate stations, such as Westfield and Te Mahia.

When I think about reducing dwell-times, four obvious sources of economic benefits spring to mind: 1) Reduced costs; 2) Existing user benefits; 3) New User Benefits; and 4) Decongestion benefits. Let’s now dive into the data (hand-waving?) ….

Cost savings: The total cost of running Auckland’s rail services is likely to be in the order of $125 million p.a. Various factors contribute to these costs, but major componenets are likely to be:

  • Staff, including drivers and train managers;
  • Operating costs, such as fuel, mainenance, and track access charges;
  • Asset depreciation, especially on the rolling stock, electrified infrastructure, and depots; and
  • Station operations, such as ticketing and security services.

Different places account for these costs in different ways, which can end up making things quite complex. To simplify things, it’s common to analyse public transport costs in terms of three underlying drivers: 1) vehicle-kilometres; 2) vehicle-hours; and 3) peak fleet requirements. These cost drivers are, more-or-less and to varying degrees, what determine the costs of the services that we operate. Shorter dwell-times won’t, of course, affect the distance that trains travel, even if they will reduce vehicle-hours and/or peak fleet requirements.

To estimate the cost savings from shorter dwell-times, I assumed that measures are taken to reduce dwell-times by 30 seconds per station. If I assume there are 15 stations on the average rail run from Swanson/Papakura/Manukau to the City, then this saves 7.5 minutes on every 55 minute run, or ~14%. I then assume that one-third of this 14% reduction in (in-service) vehicle-hours flows through to the operating cost bottom-line, that is, shorter dwell-times reduce total costs by 4.5%.

Given a total annual spend of $125 million p.a. on operating rail services in Auckland, normal practice dwell-times would reduce costs by $5.68 million p.a. If I then assume an 8% discount rate over 30 years, then this has an NPV of $69.1 million.

That’s the first example of how an apparently small number can lead to a large number when you take a network-wide, long-run perspective …

Existing user benefits: The second effect of shorter dwell-times is to expedite journeys by rail. That us, existing rail users will also benefit from faster travel-times. Current rail patronage is about 18 million journeys p.a., which is predicted to grow to 40 million in a post-CRL world. For the sake of simplicity, let us assume that Auckland averages 30 million rail passengers per year over the next 30 years.

Moreover, I now assume these passengers travel an average of 15km per rail journey. If I assume rail stations are spaced, on average, at one station per 3km, then this implies there are 4 intermediate stations per journey (NB: Remember that users will not benefit from faster dwell-times for the last station). Saving 30 seconds over 4 stations equates to a time saving of 2 minutes per journey. If I assume a value-of-time of $10 per hour, then we can monetize the value of these time savings as follows: (2/60) hours per journey x $10 per hour x 30 million journeys per year = $10 million p.a. This has an NPV of $121.6 million. Happy train users are valuable train users.

New User Benefits: Faster trains will, of course, also attract new users. Let’s assume the elasticty of demand with respect to in-vehicle travel time is -0.50. That is, a doubling in travel-time leads to a 50% decline in patronage. In turn, this means that the 14% reduction in travel-time associated from shorter dwell-times would be associated with a 7.0% increase in patronage, or an additional 2.1 million journeys p.a. If I now apply the rule-of-half, that is 2.1 million x (2/60) x $10 per hour x 0.5 = $0.35 million p.a. Or $4.3 million over 30 years.

Decongestion benefits: Some of the additional rail journeys undertaken as a consequence of faster travel-times would have otherwise been loaded onto the road network. This in turn means congestion would be higher. If I assume that 60% of new rail journeys occur in peak periods, and that 25% of these journeys would have otherwise been placed on the road network, then this suggests faster dwell-times diverts 315,000 vehicles off congested roads every year. If we again assume the average rail journey is 15km long, and that decongestion benefits are valued at $0.40 per kilometre, then I find that decongestion benefits are valued at $1.8 million p.a., or $23.0 million over a thirty year period.

Summary

Let’s summarize the estimated economic benefits of faster dwell-times:

  • Cost savings of $69.1 million
  • Existing user benefits of $121.6 million
  • New user benefits of $4.3 million
  • Decongestion benefits of $23.0 million.

Yielding a total of $217.9 million. I must acknowledge these are extremely rough and ready estimates and I could well be wrong and/or out by a decent margin of say +-50%. So don’t anyone go quoting me to the decimal point.

Notwithstanding their approximate nature, the order of magnitude of the estimate is significant. To put it in context, an economic benefit of $217.9 million is equivalent to approximately $7.3 million for every second we cut from average dwell-times. Another way to look at it: I understand the total cost of Auckland’s new trains was in the order of $500 million. Cutting 30 seconds per stop is then worth approximately half of the cost of buying completely new trains. This seems plausible to me; I suspect that a large component of the anticipated benefits of electrification would stem from faster journey times, which have not as yet materialized (NB: In some ways you could argue it’s impressive Auckland has achieved so much patronage growth despite the slow travel-times.

Anyway, the main point is to demonstrate how small time savings can quickly add-up to large dollar values when you take a network-wide, long-run perspective. This is why we harp on about dwell-times and why it’s heartening to see Council putting pressure on AT to sort this mess out. Indeed, cost savings of $69 million above would go straight to Council’s bottom-line, as would approximately $100 million in additional fare revenue over 30 years (NB: This is not an economic benefit per se at it’s simply a transfer from passengers to Council — even if it is of course a fiscal benefit). These fiscal cost savings would result in either lower rates and/or improved services.

In our increasingly resource-constrained world, I consider frugality to be not just prudent, but indeed relatively noble. This is especially true when it comes to other people’s time and money. On this topic, Benjamin Franklin, once said “The way to wealth … depends chiefly on two words, industry and frugality: that is, waste neither time nor money, but make the best use of both.” Confucius put it even more succintly when he said “he who will not economize will have to agonize”.

Or, if you prefer the words of Bruce Lee.

On that note, I suspect my marginal utility of spending more time on this post is by now lower than my next best alternative option.

Have a good ‘un.

Share this

49 comments

  1. So sorting dwell times saves 7.5m per run ~14%, then can it be argued that this is the equivalent as having 14% more trains running them as we do now?
    157 units x 14% = ~22 units, or 7 three-car sets. Around enough to run six-car sets on all peak services on the 3 main lines….?

    1. my answer to that is AT can either:
      1 bank the savings (as I have estimated here); or
      2 reinvest the savings into providing more service.

      Reality will likely see a bit of both. Perhaps more of #1 initially and then more of #2 as demand grows. Doesn’t affect the numbers though, as one assumes AT would only choose #2 if the net benefits exceeded #1.

  2. A nice summary. The benefits for the city are clear . I am not sure that psychologically 30s per station will do much. The advantages of the train are not driving in congestion, cost and often comfort. It isn t coincidence that the big growth came s more reliable service. Time ? The time gains for most are likely less than the walking time to the station anyway? Does anybody have numbers? For me the train is no faster than car but …. Better 😎

    This would explain why growth was good with a slow (er) service?

    1. Saving 7mins for those making long commutes is a serious improvement. And it is extremely valuable to drivers for these long journeys on Transit to be more appealing, they take ‘more car’ if you like, off the road.
      In terms of which aspect of the upgrade has appealed to people more, surely it’s all of the above and more, what really matters is a culture of constant improvement in all areas so the value from this investment can continue to grow.

      And the dwell time issue seems to have fallen between all the various agencies involved and been subject to the usual inertia in these sorts of systems; time for some strong leadership on the issue.

    2. hi alistair. the value of time will vary hugely between people and contexts.

      In these situations it’s probably better to rely on empirical data, rather than intuitions and/or qualitative arguments. That is, I’m a fan of looking at the effect of rail speeds on patronage in other settings and then figuring how these might translate to Auckland.

      This study:http://discovery.ucl.ac.uk/1349/1/2004_42.pdf

      Suggest an elasticity of between -0.4 and -0.9.

      My personal hunch is that the demand in Auckland will be relatively sensitive to speed, mainly because there’s a lot of competing car trips.

  3. Yes I would agree with Alistar somewhat, that the high growth has come from
    A) new trains (comfort and quieter than the old)
    B) reliability – even if the timetable is padded to allow for delays
    C) frequency – not every 30mins during peak like it used to be.
    D) station upgrades

    With the ~7min improvement that would make papakura to britomart take 45mins & waitakere to britomart 49mins.

    Both those times should be achievable goals AT are striving for

  4. Great post, Stu.

    Just one minor quibble: I think you’ve overstated the new user benefits considerably.

    1. Based on your elasticity of -0.5 and time saving of 14%, you should expect a 7% increase in patronage, not 7.5%. So 2.1m added passengers.

    2. Benefits for new users should be calculated as half of the time saving for existing passengers, not half of the average fare. So 2.1m * (2 min saved) * 0.5 * VOT = ~$0.35m/year, or $4.2m over a 30 year period.

    However, all the rest makes lots of sense; fine work!

  5. I also think you do your argument a disservice by assuming stations are around 3km apart. Tha spacing is waaay overestimated – the savings on your 15 km journey could be significantly more than you’ve calculated.

    1. Hah! Always better to be under than over. Peter above knocked $20 million off, so it’s good you’ve now identified an area where I am being conservative. If someone gives the actual numbers then I can re-calculate.

    2. P.s. I’ve recalculated with a station spacing of 1.5km on average for the user benefits, which gives total benefits of $406.7 million.

      So a range of $200 – $500 million is my guestimate, where the upper bound assumes higher intermediate stations per boarding and higher VoT.

  6. Nice article. I just started using the train because its cheaper than a carpark in the city, but my commute time is twice as long as it used to be and far less comfortable and convenient so a shorter journey would benefit me and probably many others.

    Are we assuming the same number of trains, but just running faster than currently?

    Cost savings: I don’t understand how sitting around at a station less, changes any of your operating costs. Pretty much all your standard operating costs are essentially fixed aren’t they? How can the train cost more to operate for sitting for 30s or sitting for 60s? If trains spend less time at a station, then how that is achieved is important to how your operating costs are affected. If you don’t want to discuss this, then you can’t really estimate where the cost savings may be.

    Existing user benefits: Can’t fault your general assumptions. Shorter travel time, everyone benefits with less delay. I would expect your value of time to actually be higher, like $20 or so. I know the NZTA economic evaluation manual sets this at something like $17/hr, but I think that’s focused on car drivers not PT users. Car drivers tend to be “more productive” ie tradesman. PT users tend to be more students/old people so less “productive”. I suppose the idea is that delaying a high-school student doesnt really cost the economy much as delaying a plumber. I tend to think everyone’s time is equally valuable. I would argue you get the vast majority of your benefits in this area, reducing user delays and your actual benefit could be much higher than you are estimating. Plus it is easy to calculate. You know how many people are travelling from one station to another and how much time they are saving. Easy to prove. Well, at least for AT who presumably have all that data.

    New User Benefits: I don’t think faster trains will attract new users at the rate you suggest, of course that is just an opinion. If you still only have the same number of trains and depending on origin/destination then you could on average have longer waits at the train station and negate the benefits of the overall of shorter journeys. That assumes many people are like me and just turn up at the train station when I feel like it. Sometimes I wait 30s sometimes I wait 10min. On overage I would have to wait more because the trains are less frequent. I assume they are less frequent because there is the same number of trains spending less overall time on the network. I expect you would get new users, but I don’t think you would get that growth. Positive yes, but not direct 1-1 or 1-0.5 relationship. I suppose it could be possible if there is a lot of latent demand for rail travel. Certainly rail patronage growth is showing that.

    Decongestion benefits: I’m not sure how you would calculate this. Far too complex and too many assumptions. Most parts of the road network are fine most of the day. Only congested in the peaks. Do people park and ride and cause congestion on their way? Does induced demand negate any congestion reductions after a few weeks because everyone starts driving in later because the congestion “reduced”? I agree there would be benefits, but impossible to estimate the actual benefits.

    1. Hi Ari,

      Yes, we’re assuming the same number of trains, but running faster.

      – Cost savings: See my response to Patrick above. AT has the choice of either banking the savings, e.g. by sending crews back to depot earlier and paying them less, or to run more service. What I’ve estimated here is a proxy for those benefits, because I don’t actually know what they would do. In the event they decide to run more trains to meet demand, then I’d argue my estimated savings will underestimate the true benefits, because otherwise why would you run more service?

      – Existing user benefits: Yes, I could use a higher VOT, but I was simply aiming to be in ball-park and preferably on the low-side. I’m not sure NZTA would agree that PT users have a higher VOT; traditionally it’s been the other way around.

      – New user benefits: I’ve copied my response from above. In these situations it’s probably better to rely on empirical data, rather than intuitions and/or qualitative arguments. That is, I’m a fan of looking at the effect of rail speeds on patronage in other settings and then figuring how these might translate to Auckland. This study:http://discovery.ucl.ac.uk/1349/1/2004_42.pdf, for example, suggests an elasticity range of between -0.4 and -0.9. My personal hunch is that the demand in Auckland will be relatively sensitive to speed, mainly because there’s a lot of competing car trips.

      – Decongestion benefits: Typically, you can take a strategic transport model and run iterations were you progressively (and somewhat randomly) remove trips from the network at peak hours. Using these results you can then estimate the marginal effect of additional veh-kms on congestion. To provide some context, I understand previous iterations of the EEM valued diverted-kms at more than $1 per kilometre. That seemed a little high for this context, so I used a lower rate. Naturally, the best way to estimate these savings is to run a more sophisticated model than I have on the back of my envelopes.

    2. Ari, your critique of cost savings would hold true if we simply ran all the trains regardless of timetables, capacity etc.

      However, the don’t, they run a ten minute headway at peak to provide sufficient capacity and service levels. So having faster trips means less trains and crews to meet the same level of capacity and service.

      For example, with a 60 minute trip each train takes 120 minutes to complete a cycle and get back to where it started (simplified for arguments sake, but bear with me). To get ten minute headways with a 120 minute cycle requires twelve trains in circulation.

      If that trip is cut to 55 minutes, each train cycle takes 110 minutes, and to get ten minute headways you only need eleven trains in circulation. So the same service levels, same capacity, but one fewer train and one fewer crew required in circulation = cost saving.

      It’s only one way of framing it, another might be that for the same cost you have an extra train for extra capacity and you can give a slightly better headway. Or in the case of Auckland probably a combination, you’d use the saved train unit to extend an existing three car run to six cars, so you save some of the operating cost (one fewer crew) and increase the capacity by one unit.

    3. Ari there are currently around 65 000 journeys each week day on the AKL rail network, and rising. Most of these are at the peaks, If all, or even just a proportion of these journeys were replaced by driving, then congestion would clearly be way worse. 30 000 more cars trying to get to the City Centre and other denser centres like Newmarket each morning. Even if all these journeys were on buses, which also all share the roads with cars in the areas covered by the rail network the impact on congestion would also be worse; more than a 1500 completely full buses on the roads.

      I agree calculating a monetary figure for this is a specialised art, and best left to Stu and Peter and their economist colleagues, but what I’ve outlined above shows that providing appealing and effective complementary alternative networks pass the sniff test in benefiting road users. Especially those higher value ones like freight and trade.

      Then there are clearly the benefits to direct user, and many wider benefits such as health (Transit users walk more than drivers) and environment that are not even touched on here.

      And other economic benefits such as not requiring so much land to be tied up in car parking, especially in high value areas such as the City Centre…. etc and etc

    4. Stu, I’m not suggesting PT users have more valuable time, but they should be valued equally with private vehicle owners along with pedestrians and cyclists.
      Thanks for the link, I’ll have a look when I get some time. I tend to think transport models are huge waste of time and money with questionable results and we put far too much weight on what they show. Far too many assumptions that are tweaked to get the results you want. But I guess its better than guessing.

      Nick, ok that makes sense. If you speed up enough to use one less train, then you make savings there. I suppose what I’m getting at is that until you reach the point you are using one less train, are there any operating cost savings from lower dwell times?

      Patrick, I’ve always argued for more PT spending on the basis it makes my driving commute better. There is no denying the people moving efficiency and value of good PT. I’m commuting by train now so my argument is a bit more biased.

      1. yes, I agree equivalent values-of-time are reasonable. In this case I just picked an easy number which seemed more or less reasonable once you take into account a variey of different users. In terms of transport models, I’d argue they give pretty good shorterm results in non-hypercongested networks. In terms of the value of diverted car trips my suggestion would be to pick a number between $0.10 and $1.

      2. Transport models (like any models) contain a certain amount of mystery meat, and it’s fair to question the underlying assumptions and workings. The best way to do that is to dig into the modelling process to some degree.

        What Stu’s done here is really helpful: He’s made some of the underlying assumptions and principles transparent to non-technical audiences. For instance, his post illustrates:
        * The different types of benefits that are conventionally estimated based on transport models – ie time savings for users, benefits from reduced road congestion, operating cost savings, etc.
        * How operational improvements cascade through to impacts on users.
        * A simple way of estimating changes in demand – ie look at how travel time changes, and then estimate a behavioural response.

      3. Ari, in the context of a network with four lines of reasonable length and about 40 trains on the network at peak, it only takes a small improvement to save one train.

        By my calculations saving 30 seconds per stop at every stop would save the network 50 train-minutes per hour at peak, I.e five trains worth. So one train per six seconds average dwell time reduction.

  7. You might be a bit conservative on the productivity gain from reducing the peak fleet. Shorter trips means each set gets used more times per day with the same labour cost as before. The real saving is the difference between the higher frequency service you get compared to the cost of increasing the fleet to get that same service. An increased fleet size increases costs for cleaning, storing, the additional staff and managing the additional staff etc. All of the indirect on-costs get saved as well.

    1. I suspect you’re right. I’m really only looking at the service-hours here, and the actual outcome could be that we save the need for some train-sets, which are expensive wee pieces of hello kitty.

      The reason I didn’t calculate the costs of increasing service is pure laziness; it’s a lot more involved and hence harder to communicate.

  8. AT and NZTA routinely spend more money than our entire EMU fleet cost, each year to get even less time savings for car drivers via never ending “road improvement projects”, which never deliver benefits for more than 5 years [let alone the 30 for rail savings] thanks to induced demand.
    And that is only if they deliver any at all, which is seldom measured after the fact just assumed that it did happen.

    So why is it that they’ve not bothered dealing with this persistent “elephant in the room” until AC demand it now?

    Yes I know narrow minded focus on modes, but still, a few million spent on dwell time reductions will pay many times over even at the lowest VOT and smallest amount of time saved per passenger, due to the sheer numbers of passengers carried each day on the rail.
    And why should VOT for a train passenger not match the VOT of a car driver?

    But just imagine, what sort of $ figures could be achieved if you did the same thing and focused on also reducing “dwell times” for buses – after all they carry well of 2/3rds of the passengers in Auckland. even a few seconds a stop will pay even more dividends as stops are way for frequent for buses than trains.

    Dwell times here means not just the time the bus is stationary [with the doors open] either.

    But should cover all the avoidable delays from one stop to the next, be that due to bus lanes, traffic signal pre-emption, too many bus stops over a given distance, passenger boarding/deboarding delays fare payment/cash handling delays, in all, the works.

    I’m sure we could get even better value, and more frequent services, using less buses if they weren’t so damn sluggish.

    1. Good point about buses. Of course cashless payment has improved dwell times, and this could be improved further with off bus log on and all door boarding at Stations, rather than stops.
      But improving ‘efficiency and effectiveness’ of buses also involves right of way too, especially the increase in bus lanes extent, completeness, and duration, as well as construction of fully separate right of ways like the Northern Busway…. more of all of the above as soon as possible must be a priority

      1. I caught a bus in Sydney that didn’t accept cash, you had to buy your ticket from a dairy beforehand (or opal now I’m guessing) but it seemed to be a very quick trip compared to our slow trips where you spent more time waiting for people to get change than actually moving.

    2. I reckon another type of dwell time is transfers. If our transit network is designed in a way that requires lots of transfers, then the time taken to complete that transfer can and should be costed in the same way as dwell time.

      In practice I guess that means a couple of things; first that our transit networks should be designed so as to minimise the need for transfers where possible, and secondly where transfers are part of the journey then service frequencies ought to be increased so that the high costs incurred by transfers is reduced.

      1. Currently our transport models penalise transfers at a far *higher* rate than dwell time. IMHO transfer times should be costed the same as any other journey time.

        1. Makes sense, but you have to count this properly.

          Say, you transfer onto a bus with a 15 minutes headway. Depending on schedules, that will be up to 15 minutes extra travel time, in theory an average of 7.5 minutes. However that’s not the right answer. You have to also take into account the variability.

          Sometimes that bus you’d normally just make is earlier (or you get some delay before reaching the transfer point), and the next bus is late. So it’s up to 20 minutes. Or maybe sometimes one of those buses doesn’t show up, or is full. So that becomes up to 30 minutes.

          And remember, if you have to be somewhere at a set hour, “usually around 10 minutes, but sometimes up to 30 minutes” means “30 minutes”.

          Obviously the same applies where you initially catch that first bus. But there’s still one difference. If you leave home, and it turns out there’s some problem and the next bus won’t show up for another half hour, you can go back and drive instead. But at a transfer point? Congratulations, you’re stranded.

          1. Bus punctuality would tie into what Patrick and Greg mention above. Bus priority would go a long way to making buses stick to a timetable.

    3. I agree dwell times wit buses also needs consideration. I don’t use them much now but I’m assuming AT Hop has improved things somewhat although it seems there are still plenty of people who don’t have one, despite the great fare difference which I suspect is going to continue to increase. (Already you barely have to travel much for the $10 to be covered.) Because we got AT Hop so late, it’s already time that stuff like direct payment via Paypass etc needs to be happening IMO. And longer term, just eliminating cash payment as others have done.

      12-15 years ago when I was still taking buses to the city, I remember how bad/annoying it was with the large number of cash payers who greatly slowed things down. One interesting thing was the from Pt Chev onwards, both the Ritchies and Stagecoach buses pretty much travelled the same route with same fares etc. Despite that, I still found Ritchies generally has far fewer people boarding from there onwards, even though nearly all of the Stagecoach ones were paying cash anyway.

  9. Why is Auckland so fixated on the dwell times of its EMU services. Wellington has electrification since 1938 and there has been very few moans about dwell times with its EMU services including the fleet of Matangis, so why is there so much discussion about Auckland’s dwell times?

    Surely, Wellington is more experience in operating EMU services and since that Transdev Australasia operates both the Wellington and Auckland suburban electrified rail networks, surely somebody in Transdev Auckland can talk to somebody in Tranzdev Wellington about reducing Auckland dwell times and advise solutions to AT on how to speed dwell times.

    1. You read a post explaining why we talk about dwell-times in Auckland, and then ask why there so much discussion of dwell-times in Auckland? Go figure.

      NB: The slow dwell-times are a consequence of many factors, which I don’t want to go into here. What I do want to highlight is the benefits of fixing them as a way of motivating action.

    2. Because pre EMU’s dwell times were a lot less. Dwell times have probably doubled with the introduction of a so called modern fleet which is an unacceptable situation. In fact that and slow acceleration from certain signals meant that despite these trains being capable of far quicker acceleration and overall speed, trip times had to be extended. The new trains were supposed to be better. Slower does not equal better.

  10. The Bruce Lee quote is a misquote of Benjamin Franklin:
    Dost thou love life? Then do not squander time, for that is the stuff life is made of.

        1. I read once that he wanted the turkey to be the national bird instead of the bald eagle. A turkey on the oval office floor mat would have better suited the incumbent.

  11. Thanks for this, Stu – very good to have the economic benefits quantified (and gratified at the response to my question – “why” is a wonderful word!).

    Two comments from me:

    1. I suspect that AT’s focus is more on financial benefits that economic ones, which essentially means what you’ve identified as cost savings (not sure how much of these are actually bankable) plus revenue generated by reduced journey times. Still a large number, but not quite so large – and improved productivity generates the benefit of reducing the size of the fleet required for any given level of demand (assuming that the infrastructure can cope). Needing to buy fewer new units would be real financial saving.

    2.All we need now is an assessment of the costs of such reductions in dwell times (assuming that what needs to be done has been identified – as you rightly say, not a topic for discussion here), and we’ll have the full picture.

    1. Hi Mike, thanks for your comments, and it was a good question!

      In terms of whether AT’s focus is on economic or fiscal benefits, I’m not sure it matters too much in this particular context. If you look at the fiscal benefits, then we’re talking about ~$70 million in OPEX savings and another ~$100 million in additional fare revenue, yielding $170 million. As it happens this is quite close to the ~$220 million of economic benefits quantified above. As for whether they’re bankable, I’d say they definitely are in the long run. Reason being that over time AT will need to increase service levels, such as that faster dwell-times reduces the need for additional funding to pay for these additional services. As you note we are, right now, talking about buying extra units, which implies the marginal value of shorter dwell-times could well be higher than illustrated here.

      In terms of your second point on costs, I agree that’d be useful. However, in my post I invoke a logical approach known as “proof by contradiction” to illustrate that these costs are likely to be lower than the benefits. That is, if the costs of the EMUs originally was $500 million, then we could almost afford to rebuild them completely so as to achieve faster dwell-times, and still have change leftover from the $220 million in benefits that would result. i admit this is not a concrete case, however, and that further work is necessary. But I wouldn’t be at all surprised if we could achieve 10-20 second saving for a cost of, say, $25-$50 million. Beyond that the marginal costs of extra savings might start to ramp-up.

  12. Also: peak dwells affect line capacity.
    The minimum headway between departures is composed of the theoretical headway between nonstop trains set by the signalling system plus the tine lost stopping at a station.
    The difference between a 75-second and 45-second peak period dwell at the busiest station is roughly the difference between capacity of 20 and 24 trains per hour.
    That’s why Sydney’s City Circle carried up to 24 trains per hour in the 1960s, but now can’t realistically carry more than 20, with more crowds and all double-deck trains that are poorly designed for minimising dwells.

    1. yes very good point, in the presence of line capacity constraints there is the cost of foregone patronage and/or infrastructure costs associated with alleviating the constraints.

  13. Great post. As a regular train user, the amount of time wasted sitting at stations is a huge irritation. Personally I am fortunate to have only one stop on my daily commute, but if my train commute were longer, this would probably cause me to drive my car instead of taking the train.

    What a disappointment it was when they introduced the new electric trains, only to squander the potential travel time improvement on this ridiculous performance at each station.

    Surely, given the level of investment that has been made in the new trains, AT could justify sending one of their staff overseas to find out how to run them properly?

    1. thanks for your comment and yes I agree: It was very disappointing when the EMUs were originally introduced and travel-times dropped. I recall reading some early business case for electrification that promoted how EMUs would reduce travel-times between Papakura and Britomart to 30-40 minutes. We’re along way from that now, largely it seems due to dwell-times.

      In terms of how to fix the issue, I don’t want to get into the details here. However I don’t think it’s as simple as “they’re doing something wrong” and simply need to find out what it is, Rather, I think that during the development of the EMUs technical and procedural decisions were taken that were allowed to compromise dwell-times, which we now need to reverse. But that may require changes to hardware etc.

      1. Ditch the doorsteps! Or rather, cease requiring them to be deployed at every stop and only use them when a wheelchair-user needs them. This is how the manually-deployed wheelchair ramps on Wellington’s Matangis are used.
        Just imagine the deleterious effect on Wellington’s services if the ramps were deployed at every station, whether needed or not!

  14. A good post Stu.. I was thinking along the same lines as I rode line 2 in Shanghai the other day, and I estimated that the train was waiting about 30 seconds at each station between the doors closing and the train departing. Not only does that piss the passengers off, it significantly adds to the cost. There are 30 stations on line 2 so that means the trains are taking 15 minutes longer than they should to complete each trip. The headway at the peak is 3 minutes, so I recon cutting the dwell time would save four or five trainsets. But it obviously is not easy to do. Its no doubt a function of the safety regime and a decision to make changes that might increase risk will be difficult.

Leave a Reply