Admin’s post the other day about Peak Traffic got me thinking about what some of our state highways would look like if we graphed their traffic volumes. Luckily the NZTA have published state highway volumes from between 1975 and 2010 which makes this fairly easy to do (although there are some gaps in the data which is a little annoying).

I have picked four points around the city to look at, they aren’t nessessarily the busiest parts but ones with a decent amount of data so that we can see some trends. The four places I picked are the Harbour Bridge, Northcote Rd to Tristram Ave, the SH16 causeway between Waterview and Rosebank/Pataki and the Newmarket Viaduct. Petrol Prices are often quoted as having an impact on traffic volumes so I have also added in the inflation adjusted price of petrol for the same timeframe thanks to the Ministry of Economic Development who publish it quarterly.

If you recall these two graphs, the first from the US and the second from the UK (thanks Patrick) both show traffic peaking and declining slightly over the last 4-5 years.

So who do the four spots I looked at compare?

As you can see they look very similar but interestingly all four of these lines flattened off in the early 2000’s so even earlier than the overseas ones. The only line to still have had some growth recently was Tristram to Northcote which had capacity added at the same time the busway was built but that seems to have flattened out again. That growth also hasn’t flowed onto the Harbour Bridge so is most likely a result of more local traffic using the motorway which means some of the local roads like Wairau Rd should hopefully have seen a similar reduction in traffic.

Petrol would definitely had a bit of an impact in recent years however it is worth noting that even in 2003 when petrol had come back down after a spike that vehicle numbers remained flat. Even things like the improvements to the capacity of CMJ don’t seem to have had an impact on the number of people travelling across the Newmarket Viaduct (with the exception of the periods of construction in the early 2000’s and recently with the bridge replacement).

Based on what we can see it would be interesting to see what the projections were for projects like the CMJ upgrade, if they are relying on the same long term increases that we saw before then there is a good chance the expected benefits of them won’t be fully realised.

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  1. Very interesting data. Especially to see the flattening of growth earlier than general state highway volumes flattened (from 2005). Capacity constraints seems the obvious answer there.

    It would be interesting, as you say, to see the volumes that recent motorway projects have been justified and how those stack up against reality.

  2. Hi Matt, I think this is awesome, but as a stats wonk, I’d like to see it corrected for the autocorrelation in the data (ie, the fact that each observation is based on that preceding). Because I’m feeling a tad lazy to enter the data myself, I was wondering if maybe you could send your dataset to me via admin?

    1. Interesting isn’t it?, could be many answers: perhaps petrol price doesn’t really have a net impact (or rather hasn’t so far), ie it disproportionately affects some, ie the poorer, but not everyone. Or for many types of journeys there are still no real alternatives? Or perhaps in the 80s people had more elasticity in their other spending, eg, the proportion of income going on housing may have been lower?

      On this last point I do really think that those who believe the extending sprawl is the way fix housing unaffordibility are just trading housing poverty for transport poverty. Both cost need to considered together.

      1. Agree, and never understood why this isn’t mentioned (biases?) And free marketeers are the worst, they imagine that letting the suburbs sprawl will lower cost, but if they are true user-pays advocates, they must factor in every single cost and charge for it.

        Transport, including roads must be one of them as are other utilities, but even time valuations and other opportunity costs need to be mentioned.

        And free marketeers who claim – yes but let employers set up businesses wherever they like – conveniently forget to mention that such an employer might like to build a very tall building – 50 stories in the leafy suburbs nearby to where the senior managers themselves live.

        Is that out of the free market playbook? Economic freedom is unconditional. It means freedom to build sprawl; freedom to build very expensive toll roads at private expense for the poor sods in the sprawl to pay to use; freedom to build high-rise wherever you like. These free marketeers need to be VERY careful what they wish for.

        Even Hong Kong, the land of economic freedom, has concentrated high rise urban core and suburban outliers. The market did not deliver unfettered sprawl, even where it was possible.

    2. The easy answer is: what public transport? We think things are bad now, but they were really bad in the 80s.

      Also, as you observe, a lot of other costs were relatively (as well as absolutely) much lower than they are now. Food was considerably cheaper, as were the costs of servicing a mortgage. Absorbing a big jump in the price of petrol, especially in the face of a complete lack of viable alternatives, was much easier then than now. People were more likely to be growing their own vegetables, for example, and with much less choice in consumer products there was less incentive to spend outside one’s means.

    3. While petrol was high in the early 80s, throughout the 80s the cost of owning a car reduced dramatically thanks to second hand Japanese imports becoming available for the first time. Furthermore, in the late 80s a lot of buildings were demolished and replaced with nothing (due to 87 sharemarket crash) except surface parking in the CBD.

  3. I can’t say for sure, perhaps due to the PT network being complete rubbish at that time, remember rail was virtually non existent and buses were hardly an attractive alternative with most at that time probably being old smoky and rattly things from the 60’s and 70’s. Probably still a lot of spare capacity on the roads compared to now as well so cars would still have provided a big time saving which would likely have made up for the cost increases.

    There is possibly the argument that recent increases in PT patronage aren’t simply a case of people not wanting to pay for petrol but people responding to improved service.

  4. Thanks Matt L.

    Must say I can’t really ‘get’ Auckland.

    It’s not like you once had a rail service in the ‘good old days’ and they took it away and are now restoring it. It was never there. I know you had trams but whoopy do! So does Melbourne, and so did most other developed world cities.

    On this side of the ditch, Sydney and Melbourne had developed suburban services but the other three cities of similar size to Auckland – Brisbane, Adelaide and Perth, also really didn’t have services worth the name.

    So while I understand the great conspiracy to deprive Auckland of rail-based options until the last decade, it looks to me something deeper. As if Auckland never really had a lot of transport choices, and when the motorways came they at least met some sort of need. Was the ferry network better?

    I’d love to see some evidence that road transport displaced something else.

    1. Auckland’s tram network was phenomenal. Our public transport usage was through the roof in the 1950s. 2010’s breaking the 60m boardings point was a return to the heyday of Auckland, when the population was a fraction of what it is now; In 1926, Auckland’s trams carried over 63m passengers. Consider that figure for a moment, in light of a regional population of about 230k. Auckland is still a long way short of peak public transport use of 100m boardings, and average use of 290 trips per capita (currently in the low 40s).

      Road transport absolutely replaced trams, because the tram network was pulled up at the behest of a motorway-infatuated central government who saw only the roads-centric side of the transport plan put forward.

  5. There was a rail network and it was used but not by how many currently do by the 80’s patronage was dwindling which was most likely a result of people getting disillusioned and thinking the network was about to be shut down, there was actually a spike in patronage when Robbies rail proposals were being talked about as people got hope the system would be improved.

    As for trams, they did provide the bulk of the transport for many years, most cities saw PT skyrocket during WW2 but then fall away again but Aucklands PT use stayed high for another 10 years before it fell away when the network was pulled up, even in the mid 1950’s there were over 100m PT trips per year and most of that was on trams (I believe that rail was around 4m). From what I can tell the trams were pulled out for two main reasons, the tracks/trams were aging and needed upgrading which would have taken money away from roads and that trams took up road space which could be used for more cars.

    Part of the problem was that the trams were confined to the isthmus and as Auckland outgrew it the lines were never extended or the rail network better utilised to cover this and as such when the motorways were put through it not only attracted those longer distance drivers but also the ones closer to the city

    Take a look at this graph

    1. Dead right Matt, and importantly it is that street pattern and those suburbs in part built by the tram service that remain the most desirable and valued today…leafy, walkable, with local amenity and employment, connected, democratic, with varieties of density. Retrofitting the suboptimal post 1960s auto-dependant suburbs to those standards through an expanded RTN/QTN network should be the mid term urban design aim of AC and AT. And the post above shows important steps to take.

      In this sense the future will be better the more we can get it to function like the past. This is no nostalgists’ charter though; it will take the best new tech to do it.

  6. Thanks again Matt x 2

    I’m fascinated how Auckland could go from so heavily dependent on trams to so thoroughly rid of them.

    I remember some of the Pacific Electric tales (the Roger Rabbit story) that people had been tired of the poor behaviour of the tramway operators and relished the opportunity for government to spend more money on roads. Was the Auckland tram operator accused of this?

    I suspect the following also contribute. Can’t speak for NZ but I have read that Australia experienced the Great Depression actually much worse than the rest of the world – much more severe. Also there was an uptick in economic growth and performance in the late 30s, leading into WWII in most of the world but again not in Australia (and therefore probably NZ too).

    The assets were sweated for far too long.

    At the end of the day the rural rail asset had been massively overbuilt, and only cross-subsidies that kept it going (even where you had road transport haulage limits, all that meant was the shipper was subsidising the infrastructure). No money for urban transport, which is where it was all at.

        1. It’s tempting to argue that the peak patronage of the system between 1940 and ’56 was due to wartime (petrol)rationing, however petrol rationing ended in May 1950 and the system remained popular for a further six years until full removal of the physical infrastructure led to rapid decline.

          It seems that when policy makers in NZ change their minds they pursue their ‘new’ ( but usually borrowed) idea with great single-mindedness. e.g. 1950’s urban transport policy, the fourth Labour government…..

          When the next fervently-held idea gets applied in NZ, I hope we can avoid throwing out too much of the good with the bad or redundant.

    1. In our case it wasn’t so much a case of corrupt officials or car companies buying up the tramways so they could be replaced by buses but a few influential people falling for the 1950’s car based utopia that existed and pushing that very hard with very ineffective opposition. Any subsequent attempts to fix the situation were thwarted by its fragmented nature which led to infighting and disagreements about priorities as each local council battled each other for what ever they could.

  7. Another one from Josh’s favourite site

    Now there are a couple of things there, first is the “options” and causes there that our planners lshould take into account. Such as growth wise we are in a rut so spending is some what curtailed. As our telecommunications get better, telecommuting will rise 🙂 . And we should be wary incase a further decentralisation from the core occurs.

    Which brings me to my next point; Auckland’s mass transit. Now out PT is growing especially rail and will grow even more as the population grows, the city expands, new capital projects are built and greater efficiencies are sorted from the existing system such as feeder buses, RTNs, simplification of fares and redundancy capacity building on the metro rail network. So priority one for our PT network shoud efficiency and redundancy capacity building which should (in theory) give PT a stronger leg to stand on against Central Govt due “better satisifaction rates ” with what we have (confidence building) before embarking on a billion dollar capital project or three.

    1. By 2015 pretty much the only thing left in our rail system that existed prior to 2002 will be the corridors themselves. If we can’t run a network with 95%+ reliability then that’s an utter indictment on the operator.

      In other words, we are doing the basic stuff. It is almost finished. Time to start looking at capacity enhancements and expanding the network.

      1. @admin. 98% reliability approx for rail is what the November figures were at so I say the rail operator is doing fine there. Punctuality, bloody hell that is another matter entirely and shows we are a long way off from the basics. I don’t know what you define as basics but for me it is the following:
        1) bi directional signaling from Swanson to Pukekohe (slowly being rolled out)
        2) rail cross overs between every single station to allow greater redunancy capacity and train run arounds during a breakdown
        3) Re aligning that Westfield Diamond so you can do Penrose-Sylvia Park direct opening up new route possibilities
        Then the rest such as timetables, ticketing and real time information display systems.

        Points one through to three give us the best capacity enhancements on the existing newtork before we embark on station rationalisation and relocations, bus feeders, park and rides, the airport line etc and for the icing on the cake the CRL.

        Also points one through to three will do their small part in getting punctuality back over the 85-87% mark.

    2. What makes you think we are in a rut growth wise? In Auckland at least things are really picking up and I heard a figure that over the last 12 or so months Auckland has added something like 50k new jobs.

      The other thing with telecommuting is it isn’t likely to have as great of as impact as many sprawl/anti PT/anti CBD advocates like to think, businesses get much more benefit from having people working next to each other and it just isn’t quite the same when people are not working in the same office. As an example half my team used to be based in Wellington and their roles were moved to Auckland, we are still waiting on one person to move up and even though he is in the office down there and in easy communication he still misses out on a lot of what is going and I would suggest that the team is less effective and productive as a result. Having colleagues nearby allows you to very quickly and informally run ideas past them to get better results. The same thing happens when associated businesses are located next to each other.

      1. Having people working in the same office, or at least on the same campus, is agglomeration benefits writ small.
        Telecommuting works well for outsourced things like cutting code or being a radiologist, but many other parts of business just get jammed up. Look at how badly things can go just by intra-office emails that wrongly interpreted.

      2. 50k jobs growth in Auckland? You sure some of that is not from relocating Christchurch residents that would not happened normally? Any case I say growth is in a rut if the primary figures of GDP, retail spending, manfacturing output, confidence and credit expansion are all subdued at the moment. However US confidence is up, lets hope that lasts and rubs off here.

        As for telecommuting, no opinion on that one at the moment.

        1. Yes a decent part of it has probably been from Christchurch which has seen a large dip but the point was that Auckland is growing rapidly so even though the country as a whole may not be growing quickly it doesn’t mean Auckland isn’t, if anything it is critical that investment in needed infrastructure/services in AK keep happening so that the region doesn’t become constrained and slow down as well.

        2. Auckland is projected, by central government, to account for something like 70% of national population growth over the next 30 years. That means that either central government needs to do some serious work to make the rest of the country more attractive than Auckland (which is a loser, because adding a million people across even a dozen other cities will be hugely more expensive than adding them to Auckland), or support the city that will carry all of that growth in handling that growth as efficiently as possible. Building more roads and sprawling from Whangarei to Hamilton is not efficient.

        3. Awww I thought someone wanted our very own megalopolis from Whangarei to Hamilton [/end_sarc] XD

          And no I dont…

        4. We know that the property development lobby think a sprawling suburban hell that stretches from Whagarei to Hamilton would be just groovy, and Joyce appears to agree with them. It remains to be seen whether Brownlee is of a similar mind.

  8. Actually the new technology does not lead to everyone staying at home and staring at their screen, but rather wanting to be online as they still move their physical selves around….. what do you need for that? A real good PT network, with free digital connections….

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