There was some good feedback on my earlier post suggesting a pretty radical change to the future of rail in Auckland, through the introduction of driverless rapid transit (or “Light Metro”) – much like the Skytrain in Vancouver, the JFK Airtrain in New York and systems in Copenhagen, Bangkok and Kuala Lumpur, among many other cities. Firstly, I’ve decided to call the technology “Driverless Rapid Transit (DRT)” rather than Light Metro, because so many people seem to get DRT confused with light-rail, which are really two different technologies which do different things.
The key attributes of DRT are:
it runs completely in its own right-of-way, which is fully grade separated
the train technology allows for much steeper gradients and tighter curves than regular heavy rail
the tracks are incompatible with typical heavy rail, and therefore freight
It was this last issue which raised a lot of interest in comment. How would the system work with freight? Could a freight train still get to the North Auckland Line (assuming it survives KiwiRail trying to kill it off in the next year or two)? Would you need additional tunnels and tracks? Would you need the Avondale-Southdown Line? All worthy questions that I’ll do my best to answer in this post.
Firstly, let’s remind ourselves of the system we’re talking about here. The blue line is either newly built DRT or existing rail tracks converted for DRT operation: I’ll overlay on this where I think we currently have freight movements on the network, or how we might operate freight trains in order to avoid that Westfield to Newmarket section of track we’ve turned into being exclusively for our DRT trains. The only bit of track we have to worry about here is between Parnell (where the blue line’s tunnel emerges and joins the existing network) and Newmarket, where the western line branches off. Of course there’s a fairly lengthy tunnel in this section (and an abandoned single-track tunnel next to it, which presents an opportunity worth exploring), but I think it’s reasonable to think that having a single track for freight as well as our two tracks for DRT is not impossible along this section.
Furthermore, in the longer run we could end up building the full Avondale-Southdown line, in which case we have a further route for freight: In either case I think we can retain the ability to operate freight trains around the rail network. So I don’t see that as too much of an issue.
Other comments questioned whether the operating costs savings of DRT were “worth the hassle”, as you’d need separate facilities for different types of trains and having two different networks would obviously create some complications that having everything in one network wouldn’t. I suppose there are two responses to this:
As Nick noted in a comment (and he knows more about this stuff than me), staffing generally comprises around 60-70% of the operating costs for the rail network (on an electric system). Chopping out around two-thirds of your operating cost is just immense, especially when rail’s net subsidy is over $50 million a year (I think) and would potentially be much higher in the future with a much larger network. It’s worth noting that Sydney’s rail network requires a subsidy of around $A1.8 billion a year (though obviously a much larger network).
Potentially one of the biggest savings from DRT is in the construction, with the much more forgiving requirements for grades and bends than you can get from conventional rail. With, using traditional heavy rail, North Shore Rail being around $2.5 billion and Airport Rail probably being at least $1 billion, having an option which doesn’t require so much grade separation, earthworks, tunnelling and so forth, could slice billions off the final construction cost of the two projects combined.
Perhaps the biggest question about this idea is how you would ever do the transition from normal rail operations along the southern line to the new system. I really have no idea but I presume it’s possible. But it’s the same issue we’ll face as if we ever get around to turning the Northern Busway into a railway line (of any kind).
Perhaps more than any other post on this blog, the one which really got me fascinated by Auckland’s transport future and convinced me I “wanted in” was a post by Nick R about how driverless trains – the kind used by Vancouver’s Skytrain system that I’m so fond of – could have a role in making rail to the North Shore far more affordable and feasible than perhaps we have ever thought before. There are some key elements to what Nick calls “driverless light-metro”, which make it such an incredibly appealing transit technology:
The driverless operation means that the connection between frequent and operating cost is broken (you don’t need to add a driver for every train you add). This allow off-peak service frequencies to remain high, shorter but more frequent trains to be run and operating costs of the system to be kept pretty low. Vancouver’s Skytrain system, I have heard, makes an operating profit.
The linear induction motors, the lighter vehicle weights and the technical details of these trains allow for sharper bends and steeper gradients than would ever be possible with conventional heavy rail. Nick’s posts on the technology suggest that 1 in 10 gradients are OK (the CRL is really pushing the envelope at around 1 in 28), while 35 metre radius bends are also possible – yet again much sharper than for conventional heavy rail. A more forgiving geometric requirement means much much cheaper construction cost.
Essentially, a driverless Metro is far cheaper to build and far cheaper to operate than conventional heavy rail. It almost sounds too good to be true – so what’s the catch?
Well effectively there are two main catches. Firstly, because the trains are driverless they need to be operating on a system which is completely grade separated and completely protected from pedestrian intrusion on the tracks. Secondly, the highly specialised traction technology and the less forgiving gradients mean that light-metro tracks are pretty much passenger service only (no freight) and also limited to the particular type of train you run on them – so no inter-city passenger trains or future EMUs running on these tracks. Just the driverless light-metro trains.
These restrictions create an interesting conundrum. While there’s a highly compelling case for all new rail infrastructure to be in the form of a driverless metro, for the far cheaper construction and operating costs, because we have an existing heavy rail network, which we run freight trains along and which we are also investing heavily in maintaining/upgrading as conventional heavy rail, we’re left in a tricky situation of wondering whether, and how, this fantastic technology could be used in Auckland.
Nick’s suggestion was that the North Shore Line be constructed as a Light Metro, operating pretty much independently of the existing network, with possible future extensions along SH16 and SH18 to form some sort of northwest rail loop. The case for rail on the North Shore being constructed in the form of a light-metro is, I think, compelling. Firstly the harbour crossing itself is going to be far far cheaper than for conventional heavy rail (Nick has pointed out that it could sit underneath a road tunnel or potentially even under the existing harbour bridge as unlike conventional heavy rail it would be able to handle the gradient). Secondly, one would imagine that it would be much easier to turn the Northern Busway into a light-metro line than into a conventional heavy rail line – once again because of the more forgiving geometry of the light-metro technology. With a study recently estimating that a whole heavy rail line from town to Albany up the busway being approximately $2.5 billion in cost, a light-metro line may well be significantly less than this (very significantly less if you can sling it under the existing bridge).
What has thrown a few “spanners in the works” of this plan over the past couple of months has been the general thinking of us bloggers around future operating patterns for trains once the City Rail Link is completed. In particular, the general agreement that linking up the western line and the eastern line via the CRL and the North Shore with the southern line via another tunnel, would create the most logical and best long-term operating pattern for trains passing through downtown Auckland. That creates an outcome something like this, as nicely illustrated by Patrick’s post on the matter: This operating pattern has some hugely attractive attributes:
By effectively creating four independent lines into the city centre (both directions on both lines) you have a simply huge amount of passenger capacity. If you ran 24 trains per hour each way along both lines, for example, you’d have nearly 100 trains per hour bringing people into central Auckland – around 75,000 people per hour with 750 passengers on each train.
You create a really logical route structure for Auckland’s whole network (setting aside the question of how we deal with Grafton station). There’s a basic north-south line (the blue one) and a basic east-west line (the red one). They cross over in the very heart of Auckland’s city centre.
We do away with the incredibly slow bend around Vector arena (though I’m sure you’d keep the tracks there, at least you wouldn’t need to use them for regular service).
Of course, by linking up the Southern Line with the North Shore Line, we’ve just created ourselves one heck of a headache when it comes to our idea of that North Shore line being a driverless light-metro. Or have we actually opened up an opportunity here?
What if we tried to make that “blue line” above fully driverless Light Metro? Let’s explore that idea.
If we remember back to the start of this post, the two big restrictions for driverless Light Metro is that it can’t share track with freight trains and it can’t share track with any other kind of passenger train. Effectively, it has to be its own independent network. That does create use a few headaches. But potentially they’re not impossible to solve. Let’s just say we built the line in blue below as a light-metro line: Yes, yes I know there are issues, but first let’s look at the positives. We probably have a cheaper construction cost for the Airport Line due to the easier geometry of Light Metro. We also have much lower operating costs. There’s a direct line between the North Shore and the airport, which would probably generate quite a lot of patronage and would certainly ease traffic on what’s a pretty big “through movement” at the moment (Waterview Connection eases this pressure on arterial roads but not on spaghetti junction except for people up around Albany who may use SH18/SH16).
The main issue, obviously, is that we have existing sections of track along this alignment – from Parnell right through to Onehunga and Otahuhu. However, if you add in the conventional rail network which would provide the main “south/east-west” connections, there actually isn’t much overlap between the lines at all – just between Westfield and Otahuhu by my calculations: The other key consideration is, obviously, rail freight. But from what I know the Newmarket-Westfield section of the southern line isn’t really used much by freight trains (they prefer the easier gradients of the eastern line), so the only section which would require side by side conventional and light-metro tracks would be between Parnell and Newmarket, unless some other solution can be found to send freight out west via the Avondale-Southdown line (including the Onehunga to Southdown link which isn’t shown above).
I actually kind of think all of this could work, with Auckland ending up with two completely independent rail networks. While that has some disadvantages in terms of route flexibility and the need for transfers for trips from south of Otahuhu to Newmarket (for example), I think the cost savings (both capital and operating) which would arise from being able to build both the North Shore Line and the Airport Line (at least the northern link, the eastern one is something that probably required a bit more thought) as Light Metro lines would probably run into the many billions of dollars.
Which means it’s something worth looking into. Driverless light-metro indeed could play a very important role in Auckland’s rail future.
As I noted in this recent post, Vancouver has had spectacular success with its public transport system over the past 20 years – generating huge growth in patronage, which has helped contribute to Vancouver generally performing extremely well in world liveability rankings. The comments on that post highlighted a surprising number of people who had lived in Vancouver, with two really strong themes coming through around why people thought Vancouver had been so successful:
A really simple fare system that allowed easy transfers and offered really good value for money
The Skytrain system
For this post I’m going to look at the Skytrain system, wrapped around the question of whether it offers almost the perfect solution for high volume public transport routes. Here’s the Translink description of the Skytrain system:
Launched in 1986, SkyTrain is the oldest and one of the longest fully-automated, driverless, rapid transit systems in the world. The Expo and Millennium SkyTrain Lines connect downtown Vancouver with the cities of Burnaby, New Westminster and Surrey. The Canada Line connects downtown Vancouver to the Vancouver International Airport (YVR) and the city of Richmond.
SkyTrain runs on a mostly elevated guideway, high above city streets, though there are a few stations located underground. The name SkyTrain is derived from the first SkyTrain line, the Expo Line.
British Columbia Rapid Transit Company Ltd. (BCRTC), on behalf of TransLink, maintains and operates two of the three SkyTrain lines in Metro Vancouver.
Both the Expo and the Millennium lines are operated out of BCRTC’s Operations and Maintenance Centre in Burnaby, BC where more than 630 dedicated staff work in the areas of administration, engineering, elevator and escalator maintenance, field operations, vehicle maintenance and wayside maintenance.
BCRTC currently serves about 250,000 passengers per weekday and has an on-time service delivery performance rating of 95.46 per cent.
Although the name refers to the elevation of the line, and much of the Skytrain system is elevated, this isn’t really a defining characteristic of the system in my mind. Furthermore, a very large portion of the most recent line to open, the Canada Line, is actually underground.
The three lines of the Skytrain are shown in the network map below: With only three lines, the Skytrain system certainly doesn’t have a huge amount of coverage, compared to many rail networks around the world. In fact it quite possibly has fewer route kilometres than Auckland’s rail network – which is an interesting rejoinder to those who say rail will never work in Auckland because the system isn’t extensive enough. So how successful has the Skytrain system been? Well let’s have a look at its patronage over the past 20 years: Some of the big jumps are obviously associated with the openings or extensions of lines, but it’s pretty remarkable to see a rail system which has gone from 25 million rail trips a year to 120 million trips in the space of just a couple of decades. It puts Auckland’s otherwise impressive leap from 2.5 million rail trips in 2003 to 10.5 million today into a bit of sobering perspective.
What’s the key to this success? Why is the Skytrain system used so much? How can it attract so many trips when it’s a relatively limited system in terms of its reach? Well I’d offer three main reasons for the success – although once again I’m keen to hear from those who have lived in Vancouver to see whether there’s anything else worth mentioning:
1) Convenience and Frequency
This effectively relates to the quality of service provided by the Skytrain and the usefulness that it provides for those wanting to travel around Vancouver. Obviously the system is fully grade separated, which means fast travel times even along fairly lengthy (distance wise) trips. The system is built to a high quality, well maintained and so forth.
Photo Credit: Bombardier
But the main attractiveness, I think, is the frequency of service. Because the Skytrain vehicles are driverless, the connection between adding frequency and adding operating cost has been broken – so instead of running less frequent long trains in the peak, we have extremely frequent but relatively short trains. Missed one, well that’s OK because the next train is just a minute or two away. First train full, well that’s OK because the next one will be here extremely soon. From the customer’s perspective, having a two carriage train arrive every 2 minutes is much more convenient than a 10 carriage train arriving every 10 minutes – and the driverless operation of the Skytrain enables that to happen.
But perhaps even more brilliantly, driverless operation allows for extremely good off-peak frequencies. If the main cost in operating the trains just sits in their purchase, then it makes sense to keep those train in service as much as possible. So even during off-peak times, the service frequency of the Skytrain remains exceptionally good. This is shown in the table below from Wikipedia: So on the combined section of the Expo-Millennium lines we have a train every 108 seconds at peak times (a frequency that’s extremely difficult to achieve with non-automated trains) and during off-peak a train every 3-4 minutes. So even at 10.30pm on a Sunday night, the longest you’re going to have to wait for a train on this section is 4 minutes. The longest you’ll ever have to wait for a train on combined sections of track is 10 minutes on the Canada Line. This is frequency you can live your life around and is utterly critical to the success of the system – and completely dependent on its driverless operation as otherwise it would be impossibly expensive to run such high frequencies, especially off-peak.
2) Land-Use Integration
As I previously detailed in this post, Vancouver has a number of superb examples of best-practice integration between land-use and rapid transit. Put simply, while the Skytrain system doesn’t serve a lot of Vancouver’s area, because intensification has been concentrated around the system’s stations so effectively, the Skytrain certainly does serve a big proportion of Vancouver’s population.
Not only has Vancouver located so much of its residential intensification around the Skytrain network, but also employment opportunities – and not just downtown. By having a large downtown population and many employment locations around suburban Skytrain stations, Vancouver sees really strong two-way flows of passengers, further enhancing the efficiency of the system. Major attractions, such as shopping centres, are often located next to stations. Metrotown is a classic example of this integration (both photos taken very near Metrotown station):
3) Bus Integration
The clever integration of Vancouver’s extensive and very effective bus network with the Skytrain system has, I think, been utterly critical to its success. Because the Skytrain system is not extensive, it cannot reach everywhere and therefore relies heavily on feeder bus services to deliver its passengers – so it can then operate as railways do best: doing the heavy duty, backbone of the system, work.
The bus network interchanges with the Skytrain system regularly, allowing for the Skytrain to do extremely high capacity radial journeys while the cross-town buses combined with the Skytrain enable pretty easy “anywhere to anywhere” travel with just one transfer. The network is shown in the map below: Vancouver’s excellent fares system, based around a very simple zoned-based fare structure, make transferring between services extremely simple and attractive – meaning that in total there is a much higher number of “boardings” on Vancouver’s PT network (354 million in 2011) than there are “trips” (231 million in 2011). This indicates that a very significant proportion of PT trips in Vancouver involve a transfer.
By looking at Skytrain I think we can gather some really useful learnings which are applicable around the world, including Auckland. In my mind they are:
If at all possible, try to make your rail system go driverless. It enables such excellent frequencies without prohibitively high operating costs both at peak times and off-peak times.
Developing high density residential and employment areas around the rail network is both possible and clearly market attractive in Vancouver. Find out what makes it work there and apply to Auckland.
Integrate the bus system, using rail as the backbone. Don’t worry if the rail system isn’t massively extensive, just make sure it has many many feeder buses to keep those trains full.
Ensure there’s a fare system in place which is simple and easy to understand, and which encourages transfers between services.
Readers of my recent post may recall that I’m no fan of the proposed second harbour crossing. That has a lot to do with the fact it would actually be our third harbour crossing, and our third motorway crossing at that. With traffic levels static on the Upper Harbour Bridge and actually declining on the Auckland Harbour Bridge it seems a little silly to be planning yet another motorway across the harbour, especially once we consider how effective the busway has been.
It’s not actually a case of fewer people crossing the harbour each day, that figure keeps climbing, it’s just that all the growth has occurred on public transport. More and more people cross the harbour each day… on a bus. This begs the question, why aren’t we planning a public transport crossing? A projected cost of more than five billion dollars for a harbour tunnel and it’s all just for cars and trucks. Something needs a rethink methinks.
The real problem with proposals like this is that they just won’t go away. No matter how poor the business case, how low the BCR (around 0.2 to 0.4 if you’re asking), no matter how damned expensive… I just can’t shake the resignation that sooner or later this motorway tunnel is going to get built anyway. All it takes is one minister to start using words like ‘policy alignment’ and ‘strategic fit’, and all the extensively researched economic evaluations aren’t worth toilet paper.
With that though in mind I went back to the drawing board and started to think about how we could really make a harbour tunnel work. If it abso-friggin-lutely has to be built come hell or high water, what can we do to make it a real bonus for Auckland? How can it also improve public transport, walking, cycling and urban design?
After all, it’s not like this megaproject couldn’t have some additional benefits. For a start the plan is for the tunnel to carry State Highway 1 though to Spaghetti Junction and leave just citybound traffic on the existing bridge. If they do this right the new tunnel would function as a bypass of the CBD, by taking all that heavy traffic and sending it underground and out of the way. With only city bound traffic on the bridge we could reallocate a pair of its lanes to buses, and without heavy freight traffic we would have enough strength in the clip-ons to add the proposed walking and cycling path.
More excitingly, without any need for a link between the bridge and the other motorways we could tear down the Victoria Park viaduct and free up that corner of the city. The remaining Victoria Park tunnel could be reused as a two-way link for traffic through to Cook St, perhaps even taking the bulk of traffic off Fanshawe St. In any case we could almost halve the number of lanes through St Mary’s Bay, if those lanes need only enough capacity to service the city streets and not the motorway.
There might even be a case for demoting the St Mary’s Bay motorway to an avenue style expressway, a sort-of western version of Tamaki Drive extending from a revitalised Fanshawe St boulevard. Auckland’s city waterfront could then stretch right across to it’s natural anchor at the foot of the bridge. I can see it now: rows of leafy trees, a stretch of waterside grass, cyclists whizzing along to the North Shore, kids eating ice creams as mums and dad watch the comings and goings of the marina and the harbour.
The plan for St Mary's Bay today. Fourteen lanes carrying city traffic and State Highway 1.
... and what it could look like if it only carried citybound traffic.
This all sounds very good, positively bucolic even… but truth be told we’re not really getting much value out of this yet. Five billion bucks to get some bus and cycle lanes on the bridge and tidy up the waterfront? To be frank that is the sort of thing we can do anyway at a much lesser cost, we don’t need a motorway tunnel for that. If we really want to get value out of a harbour tunnel it has to carry public transport, and I mean proper high capacity and fast rapid rail transit. Nothing else is going to move enough people to swing the numbers. Adding a rail line to the motorway tunnel could triple it’s carrying capacity at very little extra cost, if only some space could be found inside the same pair of tubes.
If we look at NZTA’s most recent proposals we are actually talking about some pretty big holes through the ground. One of the issues with boring a tunnel like this is that motorway lanes are basically rectangular in cross section, while tunnel bores are circular. It’s very much a case of fitting a square peg into a round hole. In this case the round hole will apparently need to be about 15.5m in diameter to fit in a square peg 12m wide and 4.5m tall.
The NZTA proposal for the harbour crossing. Two tubes like this would be tunnelled under the harbour.
That’s quite a lot of tunnel indeed, and in fact some of it ends up wasted. I’ve clarified the labels there because they are too hard to see, but the bottom right corner of the cross section is simply ‘cement stabilised backfill’. In other words that is just a mix of concrete and dirt poured back into the tunnel to hold the road deck up. Could we not put this space to better use?
Closer inspection of the cross section reveals the sorts of things you might expect in a tunnel: lights, fans, smoke extraction ducts. But underneath the road deck there is also a sump area to extract water, and a cable tunnel to carry pipes and wires across to the North Shore. That cable tunnel is actually pretty big, about 4m tall and 3.5m wide, could we fit a train through there? Probably not one of our new electric trains, they’re a bit too big and their overhead power lines need more height. But I do think a more compact light metro vehicle would fit in comfortably, particularly as they have a low floor height and get their power from between the rails instead of an overhead wire.
This picture shows a Bombardier ART driverless metro train to scale in that same cable tunnel, nestled in under the road deck. Instead of backfilling the empty space under the road, I’ve used it to relocate the cable tunnel to one side. This could also double as an emergency exit, or an access path to whatever emergency system they would have to install in the motorway tunnel anyway.
The same tunnel with a Bombardier ART light metro train under the road deck.
Basically, it seems with a little rejigging of the layout of our big harbour motorway tubes we could also fit through a light metro line to the North Shore. Given that it’s the same pair of bored tunnels, this rail crossing could be tacked on for minimal extra cost.
Now I must say I am no civil engineer and I couldn’t confirm if this is actually feasible, but a quick looks suggests that we very well could get both three motorway lanes and a driverless light metro track into what NTZA were proposing to build for the motorway alone. The benefits of this would be immense.
Three motorway lanes can carry about 6,000 vehicles an hour at best, which at our occupancy rates translates into about 7,500 people. The light metro systems in Vancouver and Kuala Lumpur currently carry about triple that on each track at peak times, and can theoretically move well over 30,000 people an hour each way.
Stacking metro tracks in under the road decks could easily quadruple the person carrying capacity of a harbour tunnel, and one can only imagine what that would do to the cost benefit ratio. If we must build a hugely expensive motoway tunnel under the harbour, then a shared motorway and metro tunnel could be just the thing to make the numbers stack up too.
I’ve recently been involved in casual discussions with Shoreite friends over the merits of a new harbour crossing, hearing many words in favour of motorways and railways and the like. I thought I’d use this post to outline the issues and opportunities of a new crossing to the North Shore as I see them, and outline one possible alternative for rail that might be just what the doctor ordered. Admin has touched on something very similar in the past however it could be worthwhile to take another look.
Requiem for a motorway tunnel
At first glance the NZTA proposals for a new harbour crossing are quite encouraging… that is if we assume the people of Auckland would not settle for a hideous motorway bridge destroying their new waterfront precinct and demand a tunnel instead.
A harbour tunnel certainly has it’s appeal: it would take all that state highway traffic out of St Mary’s Bay and Victoria Park and send it underground on a long invisible bypass of the city centre. We could separate peaky city commuter traffic from traffic going nowhere near downtown. It would allow us to wind back the harbour bridge to something more like a local arterial, probably with walking and cycling lanes too. We could pull down the much despised Victoria Park viaduct and remove half the lanes from St Mary’s Bay, perhaps even renovating it to act something like a western version of Tamaki Drive.
Those would be some great outcomes, but on closer inspection there are several huge issues with the harbour tunnel plan:
The approach motorway to Sydney's harbour bridge and tunnel. Do we want this in Freemans Bay and Northcote?
First and foremost, it would cost around five billion dollars. That is an absolutely huge cost, how can we fund that? What else would we forgo if we did fund it, or rather what better use could we find for several billion bucks? How many intersection improvements, bus lanes and cycleways would that fund? On five billion dollars the cost of capital alone comes in at $750,000 a day!
Secondly, do we actually ‘need’ a second motorway crossing in that same corridor? Do we need six more lanes of motorway when traffic on the existing bridge has been trending in reverse for the last half decade? After all, it only goes from the area around Onewa Rd to the Central Motorway Junction. Beyond that, do we actually ‘want’ a brand new route with plenty of capacity feeding into Spaghetti junction, something that might simply encourage more people to drive more often and create even more traffic and car dependence.
Thirdly, this five billion dollar proposal is for a motorway tunnel only, there is no public transport component. Certainly if a motorway tunnel was built this would allow a pair of lanes on the bridge to be marked for the busway, but if you think about it that wouldn’t be much improvement over the way the busway works already. Same route, same vehicles and capacity, same constraints through downtown, just a little less impact from congestion on the bridge.
Finally, would there actually be much improvement to the capacity of the transport system? A six lane tunnel would provide three lanes each way, so in the peak it could move an extra 6,000 vehicles per hour. At our occupancy levels equates to less than 8,000 people per hour. That’s less capacity than the busway, at about twelve times the price!
If we look at it again we really need to go back to the drawing board. Five billion dollars to tidy up the waterfront and duplicate a few kilometres of motorway to move only 8,000 people an hour, I don’t think so. The BCR on a motorway tunnel must be abysmally small given such a huge cost and minimal benefits.
If not a motorway, then what? Are trains an affordable option either?
What we need is something more affordable, something that will reduce traffic rather than generate more, something that has wider reaching benefits and will actually reduce travel times in the long run. Given that we already have an eight lane motorway across our harbour (plus second motorway bridge across the upper harbour), surely the next crossing should be a high quality rapid transit link. One that is cheap, compact and relatively simple to build, but can shuttle tens of thousands of people to where they need to be each day completely independent of traffic congestion.
What we really need is a crossing that can move several times as many people for half the cost. This should be possible with rapid transit: a two lane public transport tunnel would be far cheaper to build than a six lane motorway tunnel (not to mention all the associated interchanges and linkages), yet two lanes of rapid transit could carry at least twice as many people per hour than six lanes of motorway.
If we want a good cost-benefit return then it has to be public transport, the question is which form gives us the most benefit for an affordable cost.
We can probably discount a busway tunnel from the start. A bus tunnel would be relatively expensive due to the demands of ventilation and fire safety (although still miles cheaper than a motorway tunnel), yet the capacity, speed and level of service offered by a busway extension isn’t game changing. The same can be said for ‘light rail’ tramway. A electrified tram tunnel would be cheaper to build than a bus one and the capacity and service level would be better, but it’s probably still not going to give enough bang for buck. To be honest when dealing with public transport in Auckland we’re going to need a huge bang from a small buck to get one over the motorway lobby.
If we want a quantum leap in capacity, speed and service then it seems our harbour crossing needs to be based around a proper ‘heavy’ railway. However the issue once again returns to one of cost. The logical route for a North Shore rail line is to convert and extend the busway, however the grades and curves of the busway aren’t suitable for heavy rail design characteristics. So much of the busway would need to be completely rebuilt if it were to carry suburban trains, possibly with long sections in expensive tunnels. NZTA suggests the entire busway would need to be widened by three metres. The alternative of not using the busway corridor would probably mean building a new line entirely in tunnel. So constructing the train tunnel under the harbour would be relatively cheap (around $1.5 billion according to NZTA estimates), but once we add in the city side connections and North Shore extensions we can start ticking off the billions.
Admin has proposed one solution to this conundrum, suggesting that we could build the harbour rail tunnel and a heavy rail extension to Akoranga and Takapuna while leaving the busway as is. The idea is that bus passengers would continue to use the busway proper but transfer to a fast train at Akoranga for the remainder of the trip into the city, presumably until such time as we can afford to rebuild the busway as a rail line. This idea certainly has it’s merits but I doubt it could ever really work politically or garner much public support. In terms of a radio sound-bite, it is a plan to spend two billion dollars to add one new station at Takapuna. I can hear the words ‘boondoggle trainset’ already.
Driverless light-metro, ticking all the boxes at an affordable price?
What we really need is a rapid transit rail system that can run though a harbour tunnel, but also be cheaply retrofitted to the busway without any major reconstruction. It needs to provide top notch capacity and service with low operating costs, and ideally we should be able to build a whole North Shore network for less than the cost of a motorway crossing if we are really going to win over the public.
Readers of my previous post will know where I am going with this: Driverless light metro could be just the right combination for the North Shore. It’s cheap to build, cheap to run, yet fast, frequent and high quality. I’ve gone into the merits of this form of railway in a previous post, but I’ll quickly recap on what we’re talking about:
It’s driverless: Computerised operation removes the need for human drivers. This means the trains can run reliably at very fast headways without worrying about drivers missing signals. More importantly the lack of staff massively reduces marginal operating costs, and therefore allows high frequency service to be maintained all day and all night, seven days a week. I cannot stress enough this benefit, in Vancouver for example their Skytrain actually turns a small operational profit despite running every couple of minutes twenty hours a day.
It’s ‘light’: These systems are specifically designed for urban rapid transit only, so the tracks aren’t limited to what heavy rail can handle. The system used in Vancouver and Kuala Lumpur can handle curves as tight as 35m radius and hills as steep as 1 in 10, or in other words tracks about four times as tight or steep as our regular railways. The vehicles themselves are relatively compact and use third rail power supply rather than overhead line, so tunnels and underpasses can be quite a bit smaller. This all makes it ‘light’ on infrastructure and ‘light’ on cost, but not light on performance. This is a huge plus in the North Shore context, tracks could be laid straight onto the busway without modification and new branches and extensions could be built easily in and around the existing urban fabric.
It’s metro: Again these systems are custom designed just to move people, providing high frequencies, high speed and comfortable capacious trains without delays or interference from freight or anything else. With a train arriving every few minutes at every station on the line it would provide as good a service as the metros of London, Paris or New York.
In summary, a light metro system on the North Shore could be as cheap to construct as a tramway, cheaper to operate each day than buses, yet provide greater capacity and service than even a full blown suburban railway. For well less than the cost of a motorway tunnel under the harbour we could have a whole metro network for the North Shore. Indeed it could also be the perfect mode for other areas of Auckland that have no rapid transit and similar constraints to building it, in particular the northwestern corridor, the upper harbour and southeast through Howick, Botany and Flatbush.
What would a North Shore light-metro cost?
As a benchmark for costs I will use the recent Canada line light-metro that was recently built in Vancouver (which despite the name is actually two lines, a main one and a branch to the airport). The total cost of this project was $2.054 billion in 2009 Canadian dollars, which equates to about NZ$2.95 billion today. This line is actually totally independent of the rest of the Vancouver Skytrain system as it was built using Korean technology that is slightly different to the rest of the network. As such it is a good representation of a complete ‘turnkey’ network like Auckland would have to build.
This three billion dollar sum bought a total of 18.4km of double-track line (comprising 9,080m in tunnel, 7,349m on elevated viaduct, 1,386m at grade and a bridge 614m long), one major junction, 16 stations (8 underground, 6 elevated, two at grade), a operations and maintenance facility, and twenty two-car automatic trains to run on it.
So this represents a cost of NZ$160 million per kilometre for all the track, trains, stations, tunnels, bridges and viaducts needed to build and run the line. As you can see most of the Canada Line was built in tunnel or elevated, so it really represents the top end of what we would pay in Auckland given that we already have most of the corridor available at-grade. Using this rough guide we can get a ball park figure of what light metro might cost on the North Shore.
Lets start with the harbour tunnel itself, a 3.2km link from Wynyard wharf to the vicinity of Onewa Rd interchange. NZTA have estimated this would cost about $1.5 billion to construct to heavy rail standards. For the purposes of this exercise I’m going to drop this back to $1 billion to account for the fact that light-metro can handle steeper grades, tighter curves and would have a much smaller cross section so would require substantially smaller diameter tunnel tubes.
Proposed light metro lines on the North Shore (black). Stars indicate station locations and purple lines are major bus corridors.
Next up is the brand new parts of the line. For the city side connection we’ll assume a 1.4km cut and cover tunnel from the corner of Wellesley and Albert St to the start of our harbour tunnel at Wynyard wharf. This includes two stations, one at Aotea and one at Wynyard. As an aside, the site we dig out for the Wynyard station would be the perfect spot to launch the machine that bores the harbour tunnel. From the northern portal of the harbour tunnel we have a line from Onewa up to Akoranga, then from Akoranga let’s continue across Barry’s Point and the adjacent inlet to terminate our branch at an underground station under Huron St in Takapuna. So that’s an extra 3.4km of track (mostly just widening the existing motorway causeway, but with some viaduct and underground) and two new stations at Onewa and Takapuna. Altogether our brand new track requires 4.8km of track with four new stations, applying the Canadian costing gives us a rough figure of $768 million for this section. Once again I will point out this is the average cost of Vancouver’s mostly tunnelled and elevated line, so probably well above the maximum we could expect running it along the motorway in Auckland.
After this we need to look at the busway. From Akoranga to Constellation is bang on 6km long, with four existing stations that would need some level of modification. To account for the fact that most of our infrastructure already exists I’m going to (somewhat arbitrarily) halve the cost of this section. $80 million per km should be sufficient to install track, power delivery and control systems and modify the station platforms. So my guestimate is that it would cost $480 million to refit the busway proper as a light metro line.
Next would have to be an extension of the line to Albany. For this I’m going to assume a 4km route through Albany to the existing park-n-ride station, mostly elevated with short sections at grade and perhaps a tunnelled section in Albany itself. I’m also assuming two new stations: one at Rosedale Rd, the other central to the Mega Centre/University/Mall. Furthermore we will probably locate our stabling facility in the industrial area somewhere near the new Rosedale station. Once more applying our costing figure gives us a price of $640 million for this extension.
Where next? Well the obvious route would be a branch from the vicinity of Constellation station along the SH18 corridor. For the moment we’ll stop at Greenhithe Rd, but eventually this branch could reach right across the upper harbour to Henderson and the Western Line. So here we’re looking at 4.5km of line, mostly elevated, with three new stations at Unsworth/Albany Industrial estate, Albany Highway and Greenhithe respectively. Using our reference figure this comes in at $720 million. A touch pricey for those few stations but I guess the real value would come with the subsequent extension over to west Auckland.
Right, to wrap that all up we are looking at a system of a three metro lines on the North Shore running through a harbour tunnel from the CBD to Takapuna, Albany and Greenhithe respectively. This is a total of 22.5km of double track metro rail (comprised of a 3.2km harbour tunnel, 13.3km of new route and 6km of refitted busway), with five upgraded interchange stations and ten brand new ones. That’s quite a system really, it should work fantastically with a combination of decent bus feeders, the odd park-n-ride and a little intensification around stations.
But the bottom line, how much would this cost? Well to add up these simple estimates we arrive at a maximum figure of $3.6 billion to cover everything, track, stations, tunnels, trains the lot. I realise this is a very basic analysis, but using these figures that’s only 70% of what is proposed for just a motorway tunnel from the lower North Shore to Spaghetti junction. So instead of a motorway tunnel we might be able to build this whole metro system and still have $1.4 billion left in the budget to upgrade the harbour bridge or extend our metro elsewhere! Of course three-point-six-billion is still a huge amount of money, so we could obviously start with the basics first. If we exclude the Takapuna and Greenhithe branches we get a figure of roughly $2.7 billion for the metro line from central Auckland to Albany, and just over two billion if we stopped at Constellation.
So how would it operate, what would it be like to use?
The figures for Bombardier’s ART light-metro trains show that under normal conditions they operate at a top speed of 80km/h and accelerate and brake at a rate of 1.0ms-1 (the can actually brake much quicker in an emergency, and if they are running behind they can boost speed to 90km/h in catch up mode). If we plug these figures and the spacing of the stations along our proposed lines into a little model we can work out what sort of travel times we could expect.
The main line from Albany to Aotea in the central city would take just 21 minutes from end to end. That’s a full 12 minutes faster than the current timetable of the Northern Express bus to Britomart, which doesn’t even take into account the effects of major traffic congestion in the city. It would be about the same time as driving off-peak, and much faster than driving during rush hour.
What a North Shore light metro network map might look like.
The line from Greenhithe to Aotea would take only 23 minutes all up. Right now the best option is the 956 bus using Upper Harbour Drive and the busway, that takes 49 minutes. So we’ve saved an amazing 26 minutes on this route, and again this is much faster than driving if there is any sort of congestion.
The last line between Takapuna and Aotea would take only 11 minutes from end to end. This is a massive improvement over existing bus links like the 839 and 875 that actually take 30 to 35 minutes to make the short trip! Slashing travel times between Takapuna and the CBD like this would have one very good outcome: it would allow the two centres to effectively operate as a single business district. Getting from Queen St to Takapuna by light metro would take you no longer than walking up to the university or catching the bus up to K Rd.
Fast travel times are all well and good, but not if you have to wait for ages to get a train in the first place. So what are the frequencies we could expect? Well if we again assume an equivalent number of trains as used in the costings we got from Vancouver’s Canada line we arrive at a figure of 24 two-carriage sets included in the price of our network.
Based on the travel times for the three lines above we can work out that a single set can make 1.4 return trips an hour to Albany, 1.3 per hour to Greenhithe and 2.7 to Takapuna. So our 24 sets are enough to provide a train every six minutes on each line, plus have a couple of sets in reserve for operations and maintenance.
A train every six minutes on those three lines is itself is a fantastic level of service, however it gets better. Because the lines overlap there would actually be a train every three minutes between Constellation and the city, and a train every two minutes through Akoranga, Onewa and Wynyard stations! That sort of frequency makes transfers a complete breeze. With computer control maintaining regular spacing you would never wait more than three minutes to transfer between any of the three lines. And if we recall the driverless operation allows us to affordably run the system at these headways all the time, these are the same frequencies and quick transfers you’d get at any time on any day of the week. Transferring to get from Albany to Takapuna would be just as painless at 2am on a Sunday morning as it would be on a weekday at peak hour.
But what about capacity? Could a light-metro system really move more people than a huge motorway?
In a nutshell, hell yes. A motorway lane hits the wall at approximately 2,000 vehicles per hour, so our motorway tunnel would have the capacity to carry only 6,000 vehicles per hour in the peak direction. At the usual levels of vehicle occupancy that’s a maximum of just 8,000 people per hour each way through the motorway tunnel.
So what of the metro? As we worked out above our light-metro system could easily operate under the harbour at one train every two minutes each way. With a comfortable capacity of 342 passengers per two-carriage train that works out to be 10,260 people per hour each way (and quite a bit more if we are happy to crush load people in like sardines).
So just using little two-carriage train sets we can carry more people than the motorway crossing, but as patronage increases we could very simply couple more pairs of carriages together to make longer trains. With four-carriage sets the peak hourly capacity would go up to 20,520 people, and with six-carriage sets we could move 30,720 people per hour. That’s almost four times as many people as the proposed motorway tunnel.
In other words a cheap twin track light-metro tunnel could move as many people as a motorway tunnel twenty-three lanes wide!
But there’s an even bigger gulf to consider. With a motorway crossing all those 6,000 vehicles per hour have to use the same old motorways and streets either side of the tunnel. All that extra traffic will still need to funnel down either the northern motorway, Esmonde Rd and Onewa Rds at one end, and through the to the southern and north-western motorways at the other. On the other hand our light-metro system includes the cost of new tracks right up to Albany, Takapuna and Greenhithe, so we could move tens of thousands more people per hour right across the Shore and the harbour without a single extra car on the motorway. In reality we’d probably see less considerably less cars on the motorway if it were so easy to get around without driving, plus all the buses would be redeployed to feed the local stations so there would be far fewer of them in congestion on the motorway (and some arterial routes) too.
In conclusion: huge benefits at more affordable price
So there we have it, a broad indication that a truly world class metro rail system could indeed be possible right across the North Shore for the sorts of costs that have been proposed for a harbour crossing.
NZTA really should look at realistic alternatives to a hugely expensive motorway tunnel under the harbour, given that a motorway that would only further entrench Auckland into a spiral of traffic congestion and parking issues. If we do want to spend billions of dollars on transport under the harbour then why not spend it on a light-metro system that will have far greater benefits and a lower cost?
The transport section of the recently released Draft Auckland Plan makes for very encouraging reading, with the main priority being the development of Auckland’s transport infrastructure into a single cohesive network integrated with land use and development. The main ‘principle’ for achieving this (apart from a much needed look at revised and new transport funding mechanisms) is the development of Auckland’s railways into a true rapid transit system. The plan is to build the city rail link at its core and new suburban extensions at its periphery, to unleash the existing demand while promoting intensification of development in the right places to create a longer term mode shift.
Right now the City Rail Link is gathering momentum and I am confident it will be incontestable once Auckland experiences the patronage explosion that will undoubtedly accompany the new electric rail fleet. Once we have addressed the capacity and integration issues at the core, the easiest next step would be to extend the Onehunga branch via the residences and jobs of Auckland’s southwestern suburbs and the airport zone, forming a fourth main line linking from the CBD to Manukau. At this point we would be looking at a very functional rapid rail system, with new electric trains gliding seamlessly from the one side of the region, through the CBD then across the other. A network of four integrated lines sharing a tunnel at the centre carrying commuters in comfort, speed and reliability across most of the region, while providing a massive boost of access to the central city without any impact on the on the existing urban fabric. Fanstastic!
However, the question then comes: where do we go to from there? A quick glance back at the Auckland Plan shows several more rapid transit corridors, in particular routes across the North Shore via a new harbour crossing, through the outer eastern suburbs to service the growth zones of Botany and Flat Bush, plus across the upper harbour and along parts of the Northwestern motorway to provide much needed rapid transit there. To complete all of these rapid transit corridors would be the best solution we have for Auckland’s transport problems, but how to go about it?
Where to next for Auckland rapid transit, more buses and trains?
The simplest and most immediate answer is to build a series of busways, starting where they are needed the most and then expanding into longer contiguous corridors. Buses have the ability to climb just about any hill and take any corner, and can easily run on local roads where appropriate. The Northern busway is a good example of how we can pick the low hanging fruit and get some huge gains from our public transport without tackling the big and expensive issues (like a new harbour crossing) immediately.
The rapid transit network from the Auckland plan (including the NW gap). Some of the yellow and blue corridors could be very difficult to complete with heavy rail
However as we have also seen with the busway this approach is somewhat limited by it’s relatively low people carrying capacity, while the dispersed nature doesn’t promote much change in land use. It also has the unfortunate side effect of pumping tons more buses onto already congested city streets. Not exactly ideal when the goal is to decongest streets in order to work more efficiently and make them livable urban spaces. Furthermore operating rapid transit with buses can have surprisingly high staffing costs, particularly because each bus and driver can only move around 40 to 50 people at a time. This leads to high operating costs on busy peak routes, plus a tendency to cut frequencies in the off peak to avoid losing money on less busy routes.
It seems that buses are probably the best way to get the ball rolling in the short term, and we should strive for busways and bus lanes to be introduced in all major corridors as soon as possible. But to effect a significant mode shift and create a real change in land use bus based corridors can only go so far, so we need to look to the next step also.
Having discounted buses as a very effective long term solution, then perhaps the best idea to simply to expand the network through new electrified railways using the same track standards and trains as we will have already. This approach definitely has its appeal: modern electric suburban trains are fast, capacious and comfortable, they have low operating costs per passenger on busy routes, they are reliably run on their own tracks free from road congestion, and can be tunnelled under sensitive or highly developed areas. Overall rail based rapid transit is what Auckland needs to really get changes in land use and make a significant mode shift. A new rail station linked to the rest of the network by a modern train every few minutes is likely to allow people to change their travel habits, and encourage residential development and new businesses to set up shop nearby. I’m not sure if the same can be said for a bus stop on a route that leads to a busway somewhere down the road.
But railways have a critical Achilles Heel. While upgrading and integrating our existing rail lines is a very cost effective way to realise the capacity inherent in the corridors we already have, building brand new ones can be eye-wateringly expensive.
Main line railways must have particularly gentle grades and curves in order to operate at high capacity, high speed and high frequency. For example the city rail link tunnel will be at the limit of what regular trains can handle, just to make up the rise in terrain from Britomart to Mt Eden. Auckland has had to specify extra powerful EMU trains to handle the grades of 1 in 33 in the tunnel, yet over at the harbour bridge and along the busway grades of 1 in 20 are not uncommon. At the end of the day suburban rail is built to the same basic characteristics as freight trains and intercity railways.
This means in a hilly harbour city like Auckland any new line will be comprised mostly of expensive structures like cuttings, embankments, viaducts and tunnels in order to keep the line straight and even, while threading new lines into the existing urban fabric effectively means long sections of tunnel or long swathes of properties being purchased and demolished. The irony here is that the very qualities that make new suburban train lines almost essential for Auckland are the same ones that make them almost unattainable.
Now at this point I must say that new railways are still far more cost effective than trying to provide the same capacity with new motorway developments. Given a like-for-like comparison trying to build a new railway across Auckland would be expensive, but trying to build a brand new motorway would be masochistic. Yet to be realistic the cost of new urban railways is still going to be the largest stumbling block, especially with a government so intent on wasting most of our transport funds on an economically destructive fetish for boondoggle motorways.
Light metro as a third option
This leaves Auckland in something of a predicament. On one hand we need more rail based rapid transit to get the real step change in land use and mode share we need, yet we can -for now- barely secure funding for less than ideal bus based solutions. If only there was some sort of rail system that could be built and operated cheaply without the usual constraints of main line railways, but still give much the same level of superior performance we need from a rapid transit system.
Well there is. It’s not surprising to learn that Auckland isn’t the only city to have faced such a dilemma. There are many mid sized cities like ours than need a first rate transit system without spending first rate funds. Generally this has come in the form of ‘light metro’: metro style rail systems designed solely to move people around cities on dedicated corridors free of the constraints of other heavy metro or railway systems based on the demands of freight trains or intercity carriages. In this regard these metros are ‘light’ on cost and construction, but not necessarily light on capacity or performance. Note that the term metro is used here to refer to the service model, it needn’t necessarily be built underground like the metros of Paris or New York.
Light metro may present just what Auckland needs to extend its rapid transit system once the core suburban rail network is completed.
Introducing ART: New technology light metro
One such light metro system in the Bombardier Advanced Rapid Transit (ART), used most famously onVancouver’s Skytrain, but also found in various cities including Kuala Lumpur, New York, Beijing and Seoul. Although there are various other light metro systems across the globe (such as the Docklands Light Railway in London or the Copenhagen metro), I will use ART as the gold standard for light metro in this post. It is the most advanced and most common example worldwide and has the longest track record stretching back to the first line in Vancouver that has been in continuous use since 1985. One interesting point is that this technology used to be known as the “Intermediate Capacity Transit System” (or ICTS), however they dropped the name once they realised it can actually provide more capacity that many regular metro systems!
So what differentiates this system from regular trains?
First of all let’s look at the main innovations of an ART type system and see why these innovations were introduced:
1) Driverless operation
No one here but us passengers
Yep that’s right, no drivers. Much like a giant horizontal elevator, the ART is controlled entirely by a central computer system during routine operation (there is a small lockable control panel that can be used during maintenance, testing and emergency situations). Because staffing is the number one cost in any transit system this has amazing benefits. Not only does it make the system far cheaper to operate, it means the marginal cost of putting on another train is low. This is basically just the cost of the electricity used, so suddenly you only need a small number of paying passengers on each train to make running it worthwhile. This means that running trains very frequently becomes affordable, and frequencies can be kept at peak-hour levels most of the time. With driven trains the tendency is to have one bigger train run less frequently to minimise the staffing costs, say a six-carriage set every fifteen minutes. With driverless trains the costs are basically by the carriage-kilometre, making it the same cost to run a two-carriage train every five minutes as a six-carriage train every fifteen. Same number of vehicles, same capacity but three times the frequency!
It also means that without needing actual people in charge, running a train at 3am on a Sunday morning or in the middle of the night on Christmas Eve is no harder or more expensive than running one on a weekday morning. Frequent operation all day long, even 24/7/365, becomes perfectly achievable. Also the lack of a drivers cab means space for more passengers in each train, not to mention a nice view out the front windshield!
2) Computer controlled system with rolling block signalling
On most train systems lines are split into a sequential series of ‘blocks’ to keep trains a safe distance apart from each other and prevent collisions. Generally a driver cannot enter a block until the train in front is perfectly clear of it and signals like traffic lights are used to alert drivers when they can go or when they have to stop. This works fine on main lines but can cause limitations at high frequencies, and generally if you have flat junctions on the line about the best you can get away with is a train every three minutes per track. Without human drivers traditional signalling is not needed, and the ART system uses ‘rolling-block’ signalling. Here there are no fixed blocks or signals, but the computer simply ensures sufficient stopping distance is maintained between trains at all times. It’s a bit like the ‘two second rule’ for keeping a safe following distance while driving. The end result is that ART can safely run trains every 75 seconds, including routing them through junctions.
3) Linear Induction Traction Motors
Linear induction motors
This sounds a bit like something out of Star Trek, but the concept is very simple. Regular electric trains have motors attached to the wheels to provide motive power. Electric motors are very elegant machines, far more simple and powerful than diesel engines. They are basically comprised of a coil of wire wrapped around a magnet attached to a driveshaft (called a rotor). If you put current through the wire coil it creates a magnetic field, this pushes against the rotor causing it to turn and providing the force to drive the wheels. If you cut the current to a moving motor the process works in reverse in a process known as ‘regenerative braking’: moving the rotor induces a current in the coil which provides resistance for braking and converts the momentum of the train back into electricity.
A linear induction motor takes this simple concept and refines it even further. Instead of having a ring of wire the linear induction motor has it’s ‘coil’ stretched out along the underside of carriage, while the rotor takes the form of a metal plate affixed to the track between the rails. Apply current to the ‘coil’ fixed to the train and it pushes against the track itself for propulsion. The benefit here? Well firstly it means the motor has zero moving parts, thus increasing the lifetime of the equipment and reducing the cost of maintenance. But more importantly, propulsion and braking are not limited by how much traction you can get between the steel wheel and the steel rail because the train pushes magnetically against the track itself. This means that ART trains can climb and descend grades over twice as steep as conventional trains.
4) Steerable bogies
On a regular train the wheels are fixed to the bogies because the rails do all the steering. This is usually quite fine, except on tight curves where the pressure of the wheel flange against the rail can result in a nasty screeching noise and cause excessive wear on the rails. Anyone who has ridden a train into Britomart will have experienced this on the tight curve around the Vector Arena. The ART design overcomes this by having wheels that can turn into the corner much like a road vehicle. The end result is a vehicle that can take even tighter curves than normal trains without any of the noise, and less track maintenance to boot.
5) Compact body design with third rail power.
Like most light metro designs, the ART has a relatively compact body shell, lightweight aluminium construction and third rail power supply rather than overhead line. This creates a lightweight train that can climb those steep grades, yet requires only minimal amounts of clearance in tunnels or under bridges.
So how do these innovations translate into benefits for the Auckland context?
In many ways as it happens. Firstly the lighter vehicles and ability to take much steeper grades and tighter curves makes it easy to construct new routes over and around Auckland’s hilly, harbour side terrain. Ground level tracks can follow the contours of the land to a great extent; underpasses of roads need not be very deep, while elevated structures and viaducts could be much lighter and lower profile. Now nobody wants to see an elevated line blocking out the sky on Queen St or ruining the Domain, but in a place like Albany or Westgate it might be the perfect way to get stations right where they need to be.
A Bombardier ART MkII in Kula Lumpur
The relatively small cross section and agility of the ART would make tunnelling lines a much cheaper prospect also. For example a line through the CBD could be built just below the surface using the cheap cut-and-cover tunnelling method, as the line could easily follow the contours and curves of city streets. The factors would also make it simple to upgrade existing and future busways. For example the Northern Busway would need massive reconstruction and modification to support a regular rail line, but only a simple refit with rails instead of tarmac to take an ART light metro. There is also the tantilising prospect of running a metro line over the harbour bridge, as the ART could handle the grade. This could also prove to be an effective model for other busways, such as the ones mooted for the Northwestern Motorway or AMETI corridor. We can start with a busway at the core, then after ten or fifteen years upgrade and extend the corridor with light metro.
This has the potential to shave billions of the cost of building brand new rail lines (to the North Shore or the Botany-Flatbush area, for example), and makes linking them together with another tunnel through the city an economically feasible idea. While the ‘smart’ vehicles and track systems are likely to be somewhat more expensive than regular ‘dumb’ trains, the capital costs of constructing new light-metro alignments would be far far lower than the heavy rail alternative.
A second benefit is that driverless operation means they can be cheaply run at high frequency all day and night, without always needing high occupancy to offset costs. High frequency means great ‘turn-up-and-go’ accessibility, so we could design bus feeder routes around bus-to-bus interconnections without having to consider connecting to any one particular train. This high frequency also translates into high capacity. In Vancouver the Skytrain lines are usually run with just four-carriage trains, but because the come so often the peak capacity in each direction is around 25,000 people per hour. That is more than even our new EMU trains could ever achieve. Extra trains can be bought into play where and when they are needed for special events without rostering staff or paying overtime. Overall this means very affordable operating costs, which is important politically and economically. In Vancouver, a city that has lesser population density and centralised employment than our own, Skytrain actually makes an operational profit.
Thirdly, with the very fast headways and rolling block signalling made possible with computer control, flat junctions can be switched very frequently and many trains can share the same section of track over a short period. Furthermore the driverless operation means that it a terminating train takes no longer to change direction than it does to make any other stop, making it simple to operate branch lines frequently. This all provides a lot of flexibility in terms of having many lines on the map, despite only a little infrastructure on the ground. The London DLR is a good example of this benefit: this has two main lines and two branch lines linked at three junctions, but the services are typically operated along seven different patterns between various points on the network. Look at a track diagram and you see two main tracks, look at the route map on the station wall and you see seven different coloured lines each representing a separate passenger line.
Fourth, the driverless operation means that long crosstown lines become possible without concern for rotating crews or factoring in meal and rest breaks. This means we could have, for example, a line running from Orewa to Manukau all day long with it only ever stopping just long enough to let passengers on and off. That means no lengthy delays in the middle while drivers swap in and out (Melbourne is plagued by this on its City Loop), and making intermediate trips between suburbs are just as time-reliable as those to the CBD. Furthermore it almost eliminates wasted time or wasted vehicle trips, so we need less trains overall to provide the same level of passenger service.
Fifthly, the quiet motors and screech free steering make for very smooth and quiet operation, while the flexible grade and curve characteristics would make it simple to duck underground at sensitive areas. This would allow us to get stations right in close to residences and workplaces without creating noise and vibration problems, and to get routes through the city and suburbs without major impacts upon urban or natural features.
Is all this techo mumbo jumbo really realistic, what are the pitfalls?
In short, the answer is yes. These systems have been in daily operation in Canada for twenty-five years with an exceptional track record: over 1 billion passengers carried with six extensions since 1989 and no full suspension of service for construction or commissioning. The two main lines carry over 240,000 passengers a day. The linear induction motor is extremely reliable; many of Vancouver’s original 1985 Mk I trains have accumulated over 3.8 million kms with only one minor overhaul of the motor and are still going strong.
There would no doubt be various objections to introducing new light metro line to Auckland, even if the initial hurdle of political and public scepticism could be overcome. The main issue is perhaps the lack of interoperability, for example a line on the North Shore could not run into the city rail tunnel, nor could it take freight or intercity trains to the north of the country. In a way this is actually something of a benefit, the single urban-transit mode would ensure regular high frequency operation could not be disturbed by other transport uses. In the first instance connection to the other lines using the city rail tunnel should be made in the CBD and wherever else possible, but this should only be by passenger connection rather than by trying to run everything through the same set of tracks. In the second instance there already exists heavy rail lines heading north and south out of the city, and maintaining these for freight and long distance passenger access is no doubt the best idea. A new metro line would need a new stabling yard and maintenance facility, however this is likely to be the case too with any suburban rail extension.
Perhaps the best way to frame this issue is to consider a heirarchy of rail and public transport, each stage being ‘sectorised’ from each other. The first level is that of freight, regional and intercity trains, these would operate from the freight yards and Britomart terminal, using the main trunk lines to head north and south of the city. The second level is that of the suburban rail, using the existing and proposed suburban rail network and operating through the city rail tunnel very frequently at peak hours and approximating a metro system at the centre. The third level is that of our light metro, providing urban passenger-only services separate from the suburban lines. but directly interconnected with them into a wider rapid transit network. The fourth level would be street level bus and tram services, providing local access and feeding into the higher levels.
A light metro system such as Bombadier’s Advanced Rapid Transit could represent a way to establish high quality metro style rail routes across Auckland at a fraction of the capital or operating costs of conventional heavy rail or underground metro systems, meaning more lines could be built to more areas in a shorter time frame given the same amount of funding. Lines with low capital and operating costs yet frequent high quality service would no doubt perform well on any benefit-cost analysis, potentially making it much more feasible to secure funding for them.
After the essential City Rail Link is built and our existing rail lines are being used to their maximum potential, we will need to ask ourselves “where to next?” Do we look at developing the next suburban heavy rail line in Auckland, or the first metro line instead?