Following on from my post the other day about traffic volumes over the harbour bridge, I thought I would have a look at them for the entire motorway network. Listing a whole heap of numbers is never going to be that interesting so instead I have mapped them out colour coding each section of motorway based on how much traffic it carries. These come from the NZTAs annual traffic count data and is for both directions.
The busiest section by far is between Khyber Pass and Gillies Ave where almost 200,000 vehicles pass through while on SH18 the volumes are around 25-30k.
Looking at the total numbers is nice but it is perhaps more interesting to look at how this has been changing, this map shows the change from the 2007 numbers through to the 2011 numbers. What you can see is that large parts of the existing motorway network have been very flat or have gone backwards while there has been huge growth in numbers in areas next to where recent upgrades/additions have occurred.
Note: I have removed the sections that weren’t built in 2007
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Fascinating Matt. Well, yet again showing that we get the city we build…. PT growth has also been strong over this period so the road network is not a closed or zero sum system.
Yes, that’s a brilliant representation Matt L. As for the highest flow areas – no surprises there. However, completion of the Waterview link should considerably reduce future load on the Southern.
Of course the airport loop is not all motorway, but it’s interesting that the loading on either side is similar. (It’s slightly confusing that light green represents heavier flow than dark green!) One query – what is the easterly spur shown just south of the SH16 link – Greenlane Rd perhaps?
Slightly O/T, but I travelled the Maioro St-Clark St link on the weekend and can see the benefit of upgrading that link too, to improve access to New Lynn, Glen Eden and Titirangi.
As for PT, my wife successfully travelled into the city by bus this morning with our new homestay student, to show her the stops etc, but called me to collect her, haha. I guess one bus trip was enough!
Grafton Gully.
Of course! North of the domain – I should have spotted that. Thanks.
Annualising these growth rates suggests tge fastest growing segment of the highway network is experiencing 3-4% growth per annum. Sounds about right. be interesting to see how this changes when Waterview tunnels are complete … a 5-10% shift in traffic volumes from SH1 to SH16 means that the latter would gain 10-20k vpd on top of current volumes. Not insignificant!
SH20 Mt Roskill extension was completed in 2009, and Manukau extension 2010. So no surprise the traffic on SH20 increased, and on SH1 south of Manukau.
Yes, what we invest in grows, shock.
Or is it what grows we invest in? Chicken or egg my dear sir?
….guided by the perfect all knowing foresight of traffic planners; but of course!
Depends on the road really! The Onehunga bridge widening is a result of investment following demand, however the Mt Roskill extension has certainly pushed much more traffic in that area when demand wasn’t really there. Hence widening of Maioro St, which really should be included in cost of Western Ring Route, if we had level laying field with CBDRL anyway! You can see it start to change land use too, for example I’m sure the motorway extension helped Bunnings decide where to place their megastore.
I like the clearness of these maps, It would nice to have a map covering area Whangarei (SH1), Auckland, Hamilton (SH1 to Putaruru & SH 3 to Te Awamutu) and Tauranga (SH2 & SH27). I can see this being useful in explaining the important RoNS projects.
Not a bad idea but I will need a much smaller scale as most of those roads will have less than 20,000 vehicles on them