An interesting development was announcement today by the NZTA. For the Wellington Road of National Significance they have decided on what they will do between Otaki and Levin. Here’s the press release:

The NZ Transport Agency has today announced its plans for the next stage of the Otaki to Levin section of the State Highway 1 Wellington Northern Corridor Road of National Significance, proposing a staged upgrade of the existing highway, starting with a series of safety improvements between Otaki and SH57.

NZTA Wellington state highway manager Rod James confirmed that following consultation with the local community, a plan to progressively upgrade the existing SH1 and SH57 has been identified as the preferred approach. Other options considered have included new road alignments to the east and west of the existing highway, with progressive staging scenarios for two and four lane sections over time.

‘We’ve looked at various options on different routes, and we’ve decided that progressively upgrading the existing SH1 and SH57 routes is the best approach for this section of highway. This will provide for early improvements to address current problems, while also providing for the staged development of a higher standard highway as demand increases over time’.

Mr James says that a detailed package of improvements would now be developed, ahead of further consultation with the community later in the year.

‘There will be a strong safety focus to these proposals, aimed at making journeys safer for everyone. In particular, the improvements will be addressing problem areas that will be well known to regular drivers of this route, such as the Forest lakes section, rail and river bridges at Manakau and Ohau, as well as some problem intersections and providing additional passing lanes and barriers’.

Mr James says that this package will be the first stage of a long term programme of improvements, and will be followed in future by further upgrades of SH1, and SH57, progressively increasing the extent of passing lanes and barriers, and upgrades to key intersections.

Mr James says the extension of the safety improvements to the southern section of SH57 recognised the importance of the highway connection between Wellington, Levin and Palmerston North.

‘Palmerston North is a key economic hub, and by extending these improvements this will help to ensure we’ve got a safer, more robust transport and freight route where SH1 and SH57 connect.’

Mr James says studies of future traffic demand at the top section of the Wellington Northern Corridor have been a key factor in the development of this strategy. Moving north from Wellington, these projects provide improved capacity and safety for traffic on this nationally significant route, linking the central North Island with Wellington, its port, ferries and airport. Work on all of the projects between Ngauranga and Otaki has confirmed the need for a four-lane expressway for these projects. However, north of Otaki the need for a four lane expressway in the medium term future reduces, and progressively moves back to a safely designed high quality highway.

Investigations of the Otaki to Levin section have shown that the section from Otaki to SH57 is the most appropriate area for this transition to occur, and that the divergence of traffic between SH57 in the direction of Palmerston North, and SH1 north, will be a further transition point for the staging of improvements over time.

‘SH1 between Otaki and Levin is a strategically vital section of highway with high freight volumes, and it acts as a crucial connection for the Capital, both between Palmerston North and SH1 further north. However, our investigations have shown us that in terms of future growth, the projected demands on SH1 between Otaki and Levin are significantly different to SH1 south of Otaki.

‘Traffic modelling has shown it doesn’t suffer as much from the dramatic peak traffic spikes that plague drivers between Otaki and Wellington. Traffic flow is more evenly spread out throughout the day, which means there is less pressure on capacity.

‘The section of SH1 south of Otaki is also more directly affected by the booming population in Kapiti, whereas the local population north of Otaki isn’t growing at the same rate.’

Mr James says leaflets have been sent to residents living in the area, and the NZTA will release more detailed proposals for public feedback in late 2012/13.

The Otaki to Levin project is a section of the Wellington Northern Corridor Road of National Significance. The Wellington Northern Corridor (Levin to Wellington Airport) is one of seven roads of national significance that the Government has identified as essential state highways which require upgrading to reduce traffic congestion, improve safety and support economic growth in New Zealand.

What’s perhaps most interesting about this press release is that the road largely remain as a single carriageway highway but with safety improvements. Apparently by doing this the NZTA will save about $300 million and I imagine that will definitely help to ease the funding pressures they have. It also means they can start with improving on safety issues sooner rather than have to wait for more money to be available. What it also does is opens up a whole new range of questions about the RoNS, the first one that comes up is what are the RoNS standards? This time last year the former transport minister Steven Joyce was talking about the Puhoi to Wellsford road and the expectations the government had and he said this:

 But Transport Minister Steven Joyce insisted later that nothing short of a four-lane road would do.

“I don’t have a strong view as to whether the road between Warkworth and Wellsford is built on the current route or a new alignment,” he said.

“But it is crucial for it to be built to roads of national significance standard – a four-lane divided expressway – and that remains the Government’s expectation.”

It seems that the RoNS standards have changed and that opens up the projects to a whole heap of possible changes, especially for the previously mentioned Puhoi to Wellsford project. So how does that project compare to the Otaki to Levin section? The NZTA publish data on traffic volumes on state highways so we can get quite a bit of information from there and then make some assumptions. 

 I deliberately tried to pick sites that had a lot of days usage recorded and all three sites have readings from pretty much the entire year which is great. If the NZTA don’t think they can justify the building the Otaki to Levin section as an expressway, it is impossible to see how they could justify the Warkworth to Wellsford section considering it will cost at least $1 billion yet 1/3 less traffic. With the Puhoi to Warkworth section being built as a motorway it also seems like the magical traffic volume number for this to happen is somewhere between 15,000 and 17,000 vehicles per day.

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  1. Thanks for the link to the NZTA traffic volumes website and publications Matt which I have downloaded. There is a wealth of information there but my overall impression is that AADT’s have remained largely flat since 2007 and the % Heavy is often 3 to 7%. So quite a low percentage of total traffic involved in freighting goods.

    Puhoi to Wellsford % Heavy is similar and AADT’s show little traffic change. Comparing these figures with e.g. train patronage in Auckland, it’s baffling why this government wants to invest so much in new motorways. I don’t see the economic sense.

  2. The traffic is probably lower than these number because a lot of the traffic turns off south of Levin on to SH57 to go to Palmerston Nth or the Hawkes Bay. A western bypass around Levin would only capture the SH1 traffic while the SH57 traffic would use the existing route. This is given in the press release so one of the reasons for this plan.

  3. A sign that Steven Joyce can finally be ignored.

    Anyway it’s the first sign they’re not going to just throw money at huge motorways whether they’re needed or not, so this is a good sign.

    Or course Levin and Otaki are losing the Capital Connection and the Overlander stopping, so its not like the NZTA has much of a care about the communities in terms of other forms of transport.

    1. Annual Average Daily Traffic. Total annual traffic/365.

      As a measure it is quite simple, but isn’t always very relevant to typical day to day traffic conditions. It can undercook the usual state of busy commuter routes (by dividing across the weekend as well as the weekdays), and can overcook “holiday highways” by averaging all the traffic from a handful of extremely busy long weekends across the rest of year.

  4. So on average there are 30,000 journeys on Auckland’s four line rail system each day, and it is near full capacity. But there are 15,000 vehicle movements (maybe 20,000 people) on some sad bit of single lane rural highway between Otaki and Levin. That’s pretty much finished off the myth that one rail line has the same capacity as ten lanes of motorway.

    1. Auckland’s rail system is constrained to one line, not four (Britomart has only one track in and one track out). And it currently operates with much less passenger capacity per train than it will shortly. This is precisely what the City Rail Link and the new EMUs are designed to fix.

      The calculation is fairly simple.

      New Auckland EMU in six car configuration has a comfortable max capacity of 750 people.
      New Auckland signalling allows 20 trains per hour each way.
      Therefore the max capacity is 15,000 an hour each way.

      A motorway lane has the capacity for 2,000 vehicles an hour.
      A ten lane motorway therefore has capacity for 10,000 vehicles each way.
      Our motorway vehicle occupancy rate averages about 1.3.
      Therefore a ten lane motorway has the capacity to move 13,000 people an hour each way.

      This does take into account practical maximum occupancy, so at a theoretical level it’s not a valid comparison. However as experience will tell us it is perfectly possible and common in Auckland to fill trains to capacity, while cars on the motorway have never achieved average occupancy rates higher than about 1.3 per vehicle.

      1. It seems that there are about the same number of daily rail trips in Wellington as there are in Auckland… about 30,000. So the same modest rural road about 80km north of Wellington is doing half as much work as the entire Wellington rail system with lines to Kapiti, Upper Hutt, and Melling, a rail yard that uses about as much land as the rest of the CBD, and a large central railway station. Theoretical capacities are all well and good, but the reality seems to be that roads in the middle of no-where that haven’t been improved much since the 1940s transport almost as many people as the rail systems of our largest cities.

        The same seems to be the case overseas. I saw some commentary recently comparing theoretical versus actual light rail capacity in the US. Theoretically, a light rail line can transport as many people as three (???) lanes of freeway. The reality is that the best one in the states carries the equivalent of half a lane of freeway, and most carry less than a third of a lane.

        None of which is meant to detract from urban rail. We obviously need to get large numbers of people in and out of CBDs at peak time and rail is usually the best way to do that. Including in Auckland. But I’m always amazed at the transport capability of even modest roads.

        1. The rail network tends to carry most of its traffic during peak periods – the road network between Levin and Otaki carries all day freight traffic. AADT doesn’t indicate when that traffic is being moved, just what the number of people being moved is. You can’t compare 30,000 people being carried on a network between 6.30am and 9.30am and 15,000 vehicles travelling over a 24 hour period – it’s comparing apples with oranges.

        2. Not quite a direct comparison. First of all the rail network has been shut down collectively for about a month or more a year for upgrade works which significatnly affects patronage. Further wekend patronage is much lower than weekday, I believe that there is somethng like 25k trips over the weekends but over 40k per day on weekdays. The key will be how we make the weekends and off peak more useful for people as there are potentially big gains to be made by doing so.

          Its worth noting that with the CRL the daily patronage is forecast to rise over 130,000 per day

    2. Britomart is nearly at capacity because, as Matt L says, it’s one track in, one track out, and those tracks have movement conflicts for getting trains to the platforms. Auckland’s rail network isn’t even vaguely close to capacity, or wouldn’t be if we weren’t locked up by having the primary destination station as a single-line dead-end that can only cope with, at theoretical best, about 20 trains per hour.

  5. Sadly I think NZTA havent quite got the message. The reality is that the costs of projects further south of Otaki have balloned and this is the natural casualty as the furtherst part of the road from Wellington. Therefore the spare $200mill lying around in Gerrys pockets will just get reinvested in Transmission Gully and Kapiti Expressway.

    I’d be interested to know how much NZTA have spent on consultants fees to get to this point. The business case for a four lane highway north of Otaki was spurrious at best in the first case. Its just taken NZTA 18 months and many thousands of dollars to figure this out.

    Just so you Aucklanders know, its actually a double lane piece of highway in an increasingly urban environment, not some sad peice of single lane rural highway…

  6. Given Prostetnic Vogon Joyce is no longer Minister for Trucking, I wonder what percentage of the RoNS cost projections has been made up of wining & dining?

  7. “New Auckland signalling allows 20 trains per hour each way.”

    I understood that the headways are 10 minutes – what AT requested.

    That is 6 trains per hour.

    1. Services will be constrained to 10 minute frequencies due to the Britomart bottleneck but the new signalling has been designed to handle at least 15 trains per hour per direction (or 4 minute headways). Some sections, like Newmarket to Britomart, have been designed for over 20 per hour.

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