The current Metro Magazine has has an article by me on Auckland, its new urban nature, and surprise!: Why we need a change in transport infrastructure investment to unlock its true value.

Most here won’t be unfamiliar with the arguments but the discipline of writing for print and the general reader called for a rethink of the arguments and evidence. Also the photos aren’t bad either:

Metro- The City Unbound_800

Coincidentally I came across this brilliantly accessible piece by NSW transport academic Michelle Zeibots on the relationship between different urban transport systems and their outcomes for city efficiency:

Most people will take whichever transport option is fastest. They don’t care about the mode. If public transport is quicker they’ll catch a train or a bus, freeing up road space. If driving is quicker, they’ll jump in their car, adding to road congestion. In this way, public transport speeds determine road speeds. The upshot is that increasing public transport speeds is one of the best options available to governments and communities wanting to reduce road traffic congestion.

Emphasis added. This supports my assertion that the biggest winners from the new uptake in ridership on Auckland’s Rapid Transit Network are truck and car users.

This relationship is one of the key mechanisms that make city systems tick. It is basic microeconomics, people shifting between two different options until there is no advantage in shifting and equilibrium is found. We can see this relationship in data sets that make comparisons between international cities. Cities with faster public transport speeds generally have faster road speeds.

Yet parts of the highway complex in NSW are now talking about ‘solving congestion’ by building a third road crossing instead: required because of the traffic to be generated by the massive $11billion and more WestConnex project, proving, if ever proof were needed, that all motorways lead to are more motorways. And missed opportunities to invest in higher speeds on all modes through the spatial efficiency of Rapid Transit systems.

This paradoxical phenomenon is understood under various names as this Wiki page shows [Hat Tip to Nick], but perhaps this is as helpful for the average citizen as the Duckworth Lewis system is to the average cricket fan. Which is why I so like the way Zeibots has simplified it in the Sydney Morning Herald article above.

Anyway go out and grab a copy of the new Metro with the Jafa flavoured cover to see my version:

Metro cover_800

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34 comments

  1. It would be interesting to see some statistics from Auckland to see if the recent upswing in Public Transport usage has resulted in increased road speeds. Though I suspect the statistics would be skewed by the work at the Waterview junction and the lower speed limits being enforced in that area.

    1. The MoT publish some information on congestion delays based on how many minutes of delay per km people experience. Is based on surveys conducted in March and November. A quick look suggests congestion delays have been reducing in Auckland over the last decade and as we know PT has definitely increased over that time although there will be other factors too.

      As a comparison PT use in Wellington has been relatively flat and so have congestion delays

  2. Difficult to do, but one thing we do know is that the Northern Busway has kept the bridge flowing. There are more people but fewer cars crossing it now than ever before. So it is pretty safe to say that without Transit, driving would be much much slower on a number of key routes.

    There is also evidence from Wellington, and other places in the world, for shutdowns of the rail network causing major reductions in traffic travel quality.

    As the existing rail network keeps attracting riders, currently growth is topping 20%!, the largely unseen work it does to relieve pressure on the roads, especially SH1 south, will become ever more productive.

    1. The Harbour Bridge has been designed to maintain free flowing traffic for decades. I don’t think you can attribute this to the Busway.

      1. But we know it’s true: if all those bus users were driving it would be gridlock at the peaks everyday. Ferries help a little too, as does the Upper Harbour Bridge, but the bus numbers are clear and irrefutable.

        1. The design around the bridge has always been that if gridlock is to occur that it happen on the approach’s and that the bridge remain as free flowing as possible to avoid accidents and stop/start traffic. It’s been deliberately designed like that for ages. Maybe the busway has helped improve this but you can’t just make a simple observation and conclude that it is the result of the busway.

        2. I’m sorry but i can and I do. It’s an open and shut case. Anyway what major road isn’t ‘designed to be free flowing’ they all are, whether they can be or not is entirely dependant how much traffic turns up at once. You are only looking at one side, the supply side, what the bus services across the bridge do is manage the demand. Let me repeat; more PEOPLE than ever before are crossing the Bridge each day but fewer vehicles. Therefore there is less vehicle congestion but more throughput. The buses entirely maintain the efficiency of the route and, as Zeibots explains, determine vehicle speed.

        3. I think the point Kbilly is making is you would have to measure the length of queue on the approaches rather than measure any aspect of flow on the bridge itself. But you are right with the main point you are making if everyone on a bus drove their own car the whole road system would be stuffed.

        4. Clearly when I say Bridge I mean that route, there is in fact is no Busway on the bridge, but the buses there would not be nearly as effective without the Busway further north. The Bridge is just the clearest case because the alternatives are so few and also measurable; Ferries, Upper Harbour bridge, Buses, not crossing at all.

        5. As NZTA now use On-ramp lights to control the number of vehicles on the motorway to avoid queues, and while you can measure the queues on the motorway approaches to the bridge, that doesn’t tell you much at all, as most of the vehicles (latent demand) are stuck behind traffic lights at the on ramps and on local roads trying to access the on ramps.

          Stats show that in the AM peak (the most congested time on the bridge each day) nearly half the people using the bridge chose to do so using buses not in private cars – since each bus removes around 40 or so cars from the road, you don’t have to squint too hard to see how having half the AM peak bridge users being in buses but using a single traffic lane (i.e. the one with the buses on it) reduces the congestion on the motorways and harbour bridge for all the other lanes by quite some amount. Every 60 buses that go over the bridge free the same road space as a whole full lane of normal car traffic.

          And as mfwic said, if they stopped using buses tomorrow because of on ramp lights = the harbour bridge would not become a total train wreck, the local roads on the North Shore would be – flooded with cars that can’t go anywhere.

  3. I feel as though capacity improvements (of roads or public transport) will for a short period of increase travel speeds but this is not sustainable as more people will chose to travel in response to the faster speeds until the natural equilibrium speed is reached again. In urban areas we should really be looking at the benefits a transport project provides in terms of how many extra people can travel, not what (very) short term impact it will have on road speeds. I think it would be uneconomic to build/run so much transport capacity that roads and PT are no longer saturated at peak times, in the absence of proper pricing of course.

    1. The one corollary to that is that generally speaking, rapid transit doesn’t decline in travel time the more people that use it until you reach really silly levels of usage (provided you can put on enough buses and trains to meet growth).

      For example the busway could double in patronage and It will still take 25 minutes to get from Constellation to Britomart, unlike if you doubled traffic on the Northern Motorway which would destroy travel times.

      So that’s the simple benefit, building fast and capacious rapid transit next to you motorways permanently lowers the equilibrium point of what people are willing to put up with on the road.

      1. Plus on public transport, increased usage means the cost per passenger would drop because the opex pretty much stays the same – especially with trains.

        Cap ex may increase if you have to buy more trains to meet demand but that is a good “problem” to have.

        With increased motor vehicle travel, the opex goes up per user because of increased maintenance costs to the road caused by more damage from more vehicles.

        1. It was Mogeridge who put that case for public transport- upward sloping marginal cost for roads due to volume delay effects and downward sloping for public transport due to economies of scale. He was right in the short run. But in the long run trains have a capacity too. At that point you have to shell out an absolute fortune to increase capacity by a huge amount and then you have economies of scale again. Thameslink was a good example. It had to be diverted away from London Bridge in the peak because of a lack of capacity across the Thames so instead it went to Blackfriars. To add capacity would have required another tunnel and track and then there would have been free capacity for years.

        2. Yes the costs of adding to PT tends to come in jumps for capex [new trains or lines] but between the jumps there is a decline in opex cost per user, and as Nick points out above generally an increase in service [more frequency and capacity]. There is a similar but different arc for driving; it is also subject to big jumps in capex [new motorway, extra lanes], but in contrast to a Rapid Transit route the level of service declines as it gets busier. What we generally call congestion.

          Bit of an oversimplification, as Transit users also experience congestion; human congestion. I’ve had plenty of experience of that, especially in London. But unlike a clogged motorway heaps of people flooding out of a Transit Station is a great economic resource, and of course a much lighter load on our resource base and environment.

        3. Transit looks especially good of course if you take into effect the cost of supplying parking for cars – both monetary and opportunity costs. Think of what we could do with all the space currently used for parking.

          For cycling in particular, doing away with parking as such a sacred cow would make a huge difference and start a virtuous cycle of less people driving as they switched to cycling. This would also free up space for bus lanes – a super effective way to move people around for almost zero cost.

          Labouring a point (but I think a good one), let’s at least agree as a general principle that arterial roads are for moving people, not the storage of private property.

        4. Well that’s the case we have with the CRL, we have a network of three main lines, two branches and forty something stations that are all well under capacity… we need to bite the bullet on a chunk of capex to fix that, but afterwards we’re back into many years of travel times improving the more people use it (based on more capacity delivering more frequency). Damned good investment, one tunnel to more than double the capacity of the entire network.

  4. It would be interesting to know how trip numbers and mode share have changed in relation to population increases. Has the total number of work & education trips increased in proportion to the increase in the population? Can a causal link be established between higher uptake of PT and lower uptake of cars? For example, is the Northern Busway effect on Harbour Bridge traffic reflected in other areas with improved rail coverage (Onehunga, Pukekohe), or is it also reflected in areas without PT improvement (such as Howick)?

    1. Well population is going at some 2.3% PT ridership at 8%, rail and busway at 20%. Driving as measured by VKT in Auckland is still below its 2006 per capita peak, therefore <2.3%

      Time to invest in the growing mode. Zeibots is right, surely, that there will be a constant interplay between modes depending on what we supply. For 60 years we have only tried to supply more road space, looks like the best investment now is in improving alternatives to compliment this rich resource.

      These are things I unpack in the article.

  5. Interesting the idea about PT speed tends to match road speed due to an arbitrage effect.

    In Helsinki we live roughly 24 kms from the CBD and the train from the nearby station took about 24 minutes. So roughly 60km/hr while my wife’s car indicated 58 km/hr for a mixture of urban and inter city driving.

  6. The relative time taken for the trip between PT and driving is only one factor. But I agree it is an important one.
    I live less than 5km away from where I work and can reach it on local mostly uncongested roads. there is a reasonably good bus alternative. But as I don’t have to pay for parking and the drive is faster than taking the bus I naturally drive to work.

    P.S. if there was a busway on the one congested road, that the bus takes but I avoid then I would certainly reconsider my transport options.

    1. Yes it’s an ‘all other things being equal’ kind of rule. Obviously there will be all sorts of reasons why people each make their specific choices but over the numbers observable in cities each individual choice eventually add up to a trend. Like we are seeing now on Auckland’s PT services, and specially on the Rapid Transit network.

      The important thing is that our investment decisions have huge influence on this, and Auckland is now clearly at a point where investment in the underdeveloped non-driving modes is the best way to lift performance and resilience on for all modes.

      1. 110km/ph improves the BCR rating – time savings one of the prime factors used to justify new roads……as very well explained on this website –
        http://greaterakl.wpengine.com/2014/07/17/guide-to-economic-evaluation-part-2-what-are-the-benefits-of-transport-projects/

        One of the key quotes from Peter Nunn’s post:
        ‘The third important fact about transport benefits is that travel time savings make up the majority of measured benefits. Under conventional evaluation procedures, the main benefit of new transport projects is almost always that they save time for travellers. Other benefits, including vehicle operating cost savings and emissions reductions, are minor by comparison. Moreover, as alluded to above, travel time savings cannot be equated to increased economic activity.’

        So there you have it. The speed limit is being raised 110 km/ph to try to tweak the numbers to justify RoNS with incredible bad numbers!
        Unfortunately, a cerebral argument – to quote a certain politician: ‘Nu Zulunders are not interested in this sort of stuff”.

      2. That’s a bit harsh on Waikato Expressway though, which -only once completed in 2019- will become the main route between Auckland and the south.

        1. And? Like the Holiday Highway, will be right next to an existing and far from capacity one, that will become a financial burden on the local authority. We are building State Highways too big, too soon, and often in the wrong places. This is spending for very low return; poor economics.

  7. If you are parked on the motorway or crawling then a 110kph speed limit is of no benefit. Our car is definitely much more fuel efficient at 70 to 80kph than at 100kph.

  8. LOL. Why did you even bother to post. It’s going to get deleted for not contributing anything of worth to the conversation.

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