A few months ago I analysed the proposed widening to State Highway 16 in Auckland, from a rather critical aspects – as in my opinion it is a rather pointless task spending $860 million to widen a motorway when, over the course of just a few years, I think it’s quite likely the motorway will end up just as congested as it is now – due to the effects of “induced demand“.
December’s meeting of the Auckland City Council Transport Committee includes a report into the State Highway 16 widening project. That report has some interesting, and fairly complex, recommendations. These give an idea about the concerns that Auckland City Council has about this project, although it is interesting to note that the council does still – in general – support the project:
There is also a series of maps that show potential property and open space effects of the proposed widening. It is important to remember that the is an Auckland City Council report, so it doesn’t consider any of the project’s potential effects on areas within Waitakere City – that is, anywhere to the west of the bridge just west of the Rosebank peninsula. Here are the maps, in sequence from east (the city end) to west:
I must say, it would certainly be nice for the St Lukes Road overbridge to have a footpath on both sides of it – so at least it is likely there would be some improvement to the area from the motorway widening!
I must say it’s a bit disappointing to realise that the Chamberlain Park Golf Course will be further impacted by state highway 16. When this motorway way put through in around 1980 the golf course was highly impacts – and in fact was split off from its original clubhouse on Great North Road – and its linkage with other areas of public open space such as Western Springs Park and the Zoo. A pedestrian overbridge in this vicinity would be a small, but useful compensation for the enormous effect the motorway has had on splitting in half what would be one of the larger areas of open space within this part of the Auckland isthmus.
This seems to be the area where much of the impact on private properties will be (as well as around Waterview just to the west). The further widening of a motorway that cuts off Pt Chevalier from the area to the south of it will need to be managed carefully to ensure it does not create further severance. It will be interesting to see if that can ensure things don’t get worse, or hopefully somehow reduce this sense of severance.
From the maps above, it would appear to me as though the causeway will be significantly widened. That will have quite a big effect on our harbour – of course that effect might well be outweighed by the benefits the road is supposed to bring, but it must surely be realised that the new causeway might well be close to twice the width of the current causeway. Ironically, even though its width is going to be widened so massively, there’s apparently still not enough room for a “proper busway”.
It’s good to see, in this image, that there won’t be further impacts in this area on the seaward side of the motorway.
Overall, I think it will be interesting to see how this project will fare during a consenting process. It appears to me as though the benefits of it, which I think are very minor due to induced demand, are unlikely to “outweigh” its environmental (and fiscal for that matter) costs.
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Hmmm… I gotta say I like what the ACC has done on the Waterview and SH16 announcements recently… There are basically saying if you are determined to build these hideously expensive wastes of time projects (and Joyce is) then we better get some other modes and environmental mitigation in return… Has Banks realised there is votes in the environment..?
A certain road engineer has said the reason the causeway is so wide is water is going to run through the extra capacity of the new used part of the causeway, treating it better, if a busway was to be build either pipes and pumps would have to be put under the unused, drainage part of the causeway widening or an even wider causeway would have to be built… No future proofing… Sigh…
That “certain road engineer” is talking rubbish on that matter. There are always a variety of ways to treat stormwater, plus it is not exactly UTTERLY ESSENTIAL to do it, although obviously preferable where possible.
Well that is good news as we have ourselves a nice wide area for a Busway… Now to get the ARC to amend to a RTN and leave a space at interchanges…
Indeed. I’m looking forward to the RLTS hearings in Feb next year.
Hopefully I can come present my submission.
I do think work needs to be done on SH16 in some areas but apart from raising it, the causeway is not one of them that (although it is cool to drive along when the tide is right in as you almost feel like you are about to go swimming). As a life long westie who has travelled this road many times before in all sorts of different conditions I have put my thoughts below each part and what needs to be done to it.
1. Westgate to Te Atatu – Needs to be 6 lanes plus a busway.
2. Te Atatu to Pt Chev (The causeway) – This seems wide enough with at 6 lanes and with the exception of adding a bus way to it, I wouldn’t widen it any further.
3. Pt Chev to Western Springs – needs to be 8 lanes with a busway on the side (this means an extra lane on the city bound side to cope with the extra traffic from SH20)
4. Western Springs to City – no changes needed here as the part of the motorway that is busy is the link to the southern and the city off ramp is usually fairly clear. Also when the busway is turned into a rail line it should go from western springs under arch hill and through Ponsonby to the city rather than follow the motorway.
I generally agree Matt. I think once motorways get beyond 6 lanes there’s definitely a “law of diminishing returns” for the benefit one gets from adding extra lanes. Most of Auckland’s widest bits of motorway are also the most congested.
Of course the problem is not the motorway but getting cars off it again, adding extra lanes just creates a bigger parking lot meaning you get closer to your destination before you stop. Te Atatu is the main issue on the north western. It has been improved in the last few years but still causes most of the problems as once past there the traffic generally flows at about 80 in rush hour.
Wouldn’t a local road link between Rosebank Rd and Te Atatu Road, across the Whau River, make a big difference there? Then traffic could split between the two exits.
If NZTA had any sense, they would realise how local road upgrades are more important than motorway upgrades in many cases. Give people more options then you won’t have to widen existing options.
I think the planned bridge between around hebburn and rosebank would be better, currently anyone from either Glen Eden, Titirangi, Oratia, Glendene and some parts of Henderson have a long trip to get to either the Te Atatu or Pt Chev interchange. This means it could also effectively remove a lot of traffic from the local roads approaching the interchanges.
“That “certain road engineer” is talking rubbish on that matter. There are always a variety of ways to treat stormwater, plus it is not exactly UTTERLY ESSENTIAL to do it, although obviously preferable where possible”
Now day’s it is essential to do it, in fact ARC won’t let you do anything unless you treat the stormwater, it is part of every project in todays environment. Which is good.
Also yes their are other ways of treating stormwater, but neither are they as good, but also require a hell of a lot more maintenance and the local councils, who it will be handed over to, (Auckland Council soon) don’t have a good track record in that department. So I don’t think he is talking rubbish just logic.
However I must agree with the councils view – ‘the project is essential however these things must also be adressed at the same time.’
As a planner myself, when it comes to environmental effects the key is to look at the different options and find a “least bad” outcome. I agree that not treating stormwater is certainly not ideal, but then not having a busway will also have significant adverse environmental effects in my opinion. The same goes for widening the causeway enough for both the busway and a runoff area.
It is about finding the best balance, which may end up involving pumping the water to treatment ponds at Te Atatu or Pt Chev where there is more room, or having a few treatment ponds along the causeway.
For the Manukau Harbour Crossing Project I read hundreds of pages of stormwater information, so I have a reasonable idea of what is possible.
The Manukau Habour Crossing treats all it’s stormwater on site, during construction through sediment ponds and decants, while after construction through swales, sediment ponds (3 including 1 at tararata 1 at nelison st interchange and the other near beachcroft rd/queenstown interchange) and stormwater filters under the pavement. During Construction they’ve had over 90% 1 and 2’s, ARC standards are 80%.
Manukau Harbour Crossing is actually a fine example; all the stormwater on the manukau harbour crossing project is treated without pumping but by using the land surrounding it within it’s corridor, even the old bridge which used to discharge straight into the manukau harbour has been retro-fitted to treat the stormwater. It’s a very good exapmle of using typical stormwater treatment which requires minimal maintenance. The problem with alot of other techniques is if it’s not maintaned to appropraite standards the water is no longer treated and they are better off not been used.
So that example really reinforces my point of having to have stormwater treatment, when applying for concents etc. the ARC doesn’t take into acount where you may be reducing the environmental effect and subtract from your sediment control procedures, sediment control comes first.
Please note, I agree we need a busway along that route, but I can also see the point of the Road Engineer Jeremy was talking about. We would need to either widen the causeway further or rely on insuperior stormwater treatment which I would be unsure ARC would allow.
Is there any potential to use a busway as the treatment zone, say through the use of the new fandangled permeable pavements I keep hearing about?
Good idea Nick, not sure about durability with heavy weights and costs though… But surely an environmentally friendly piece of infrastructure could be our first large scale use of this material..?
Well buses are fairly heavy, but they are nothing compared to laden trucks. So presumably the pavement of a busway that only carries ten ton buses could be to a much lower standard than your average motorway or arterial that must support fifty ton trucks.
Hmm, so apparently there are a variety of porous concrete and paving products out there, some which claim to be suitable for heavy traffic applications.
I do wonder… the current plan seems to be for impermeable motoway lanes with a similarly impermeable shoulder that can support bus use, plus a large buffer of a very permeable surface (planted soil and aggregate I assume) for stormwater/runoff treatment.
What if they were to build impermeable motorway lanes but have permeable saftey shoulders, ones that don’t carry buses and therefore don’t need a stong surface at all. Then a busway paved in a semi-permeable pavement could be built in part of the buffer zone with the rest planted, etc. Perhaps this might allow the same level of stormwater capacity as the current concept. Permeable pavement might even be superior in some regards, as some products seem to be designed to trap heavy metals and oils.
Methinks you have a plan, my friend…
Wouldn’t ballasted rail on the side be even more porous than the road for a busway? 😉
You know Matt you might be on to something there!
We’d be damned lucky to get even a busway, let along a rail line… but it does leave hope for using that corridor in the future. Perhaps once the CBD tunnel is built and they have something to connect it to.
At the end of the day i’m not to concerned if they don’t build a busway at the same time as long as they leave the space needed for a rail line so it doesn’t end up costing us $3b when we finally realise we need it.
With the railway though my plan would go something like this.
1. Buy TBM
2. Dig CBD tunnels
3. Turn it around and dig 1 tunnel out under Ponsonby to Western Springs.
4. Turn around again and dig matching tunnel back to the CBD loop and then continue out to the North Shore to join with the busway.
Surely a big part of the cost of digging the tunnels is buying and setting up the TBM and associated equipment. Once we have it running we should just keep digging
Yes, I think a rail line running on the surface along SH16 as far as the start of the Arch Hill Scenic reserve, where a portal in the cliff face could connect to a tunnel under Ponsonby to the vicinity of the Midtown station.
There could be underground stations at Ponsonby Rd and Grey Lynn, and surface stations at Western Springs/Motat/Zoo, Pt Chevalier and points further out to Westgate.
A grand plan, but if we have a CBD tunnel and skyrocketing rail patronage perhaps it might become feasible to put it on the agenda. Having said that, I would like to see lines to the south east and south west first, those should be the priority.
Agree absolutely about the Te Atatu Rd- Rosebank Rd connection. Will be a million times more cost- effective that building a mega interchange at Te Atatu Rd.
The other link that will save huge amounts of time and fuel is to connect the top of Te Atatu Peninsula with West Harbour (which are a stones through apart).
If you built these two connections, you wouldn’t need to widen SH16. Studies show most of the traffic on the SH’s are local. In Auckland the only bridges only seem to be on the motorways- no wonder we have so much congestion.
TopCat, yes that’s why the government’s focus on state highways and urban motorways is so non-sensical. The benefits from widening existing routes is less than having new routes offering different options.
ARTA’s onto it and realise that it’s Auckland’s arterial roads that need more focus (as well as public transport of course).
@admin, you say ARTA’s on to it but what evidence is there that they are? I would be interested in seeing if any investigation has been done around the benefits of widening the motorway compared to creating a few new links in key places that would cause traffic to spread out over the existing interchanges better.
This is one of the main areas that I am hoping the Super City will be able to bring some stronger guidance on rather than the fragmented approach that currently exists with each council only looking at their little patch
Matt, unfortunately ARTA have little ability to “give effect” to what they want to do. While we may hope the super city gives us a little more power in that respect – the wording of the legislation establishing the Auckland Transport Agency suggests that it will be the Auckland branch of the NZTA rather than the transport branch of the Auckland Council: http://joelcayford.blogspot.com/2009/12/auckland-transport-authority-bill.html
Buses fully loaded are actually heavier than a fully loaded truck, both have the same weight restrictions on them however trucks are policed, and who is going to pull over a fully loaded bus take it to a weigh station with all the passengers inside? This means buses are able to overload and in peak time do so. Not saying it’s a bad thing, just saying they do do allot of pavement dammage.
Shouldn’t really be saying this; hopefully roading lobbyists aren’t reading.
Joshua, do you have a source to support that claim, because I think it is actually quite the opposite. The information I have seen indicates a fully laden bus weighs around 10 ton (7-8 ton of vehicle and 2-3 ton of passengers) while the current legal limit for trucks is 44 ton, so laden trucks are a good four to five times heavier than laden buses. This appears to be NZTA’s view too, as they were forced to ban trucks from the clip-ons while buses were unaffected.
Assuming that new motorway lanes are built to full truck standards, bus only lanes need not be built to such a high specification.
Chamberlain Park is only theoretically in public ownership.
It is leased out to the Golf Club and there is limited public access.
Yes that’s true Lindsey, although it is still green space.
Nick R – Im not sure on the facts as I got the information from my Urban Transport Planning Lecture. However it was more informing of a overloaded bus (this would be more acurate than saying fully loaded) as buses apparantly have a limit on the amount of passangers but these are not usually aheard to so the bus is actually overloaded. Most likely I may be wrong however as my information was from the lecturers mouth, and not notes containing facts.
I think that must have been in another context then Joshua. You can normally see the capacity limit of bus on a plaque near the front door. I always have a bit of fun counting the number of people on my bus, it’s almost always over the legal limit if there are people crammed in the aisle. Interestingly in Victoria there is no equivalent legal limit for trains, as long as the doors can close it is ‘legal’.