The ATAP final report includes a 30 year vision for Auckland’s strategic public transport network. It is a substantial expansion of what we have today and quite closely resembles our “Congestion Free Network” developed in 2013:
ATAP generally goes out of its way to avoid making a call on the specific mode of new strategic public transport projects, instead using the phrase “mass transit”. However, it does show CRL as the only expansion of the heavy rail network (in red) with all other new strategic PT routes presumably being something other than heavy rail. Elsewhere, ATAP notes the need for ongoing investment in upgrading the existing heavy rail network over time to provide for growth in passenger and freight services – but not an “expansion” of that network.
This is quite a change from the 2012 Auckland Plan, which envisaged heavy rail to the Airport, the Avondale-Southdown Line and, in the longer term, rail to the North Shore. At times we have also seen the Mt Roskill rail spur being considered as another useful (if relatively small) expansion of the heavy rail network.
This change appears to have occurred on a relatively ad hoc project by project basis, rather than as part of an overall strategic plan, which I think sits behind much of the discomfort that people have felt about Auckland Transport decision to progress light-rail, rather than heavy rail, as their preferred strategic public transport mode to the Airport. It is worth thinking about this shift at a network level, in particular at the question of whether further expansion of the heavy rail network is likely. If not, it seems that CRL may actually be the end of the heavy rail network – rather than a key catalyst for its expansion.
Compared to other PT modes, heavy rail has some advantages and disadvantages:
- Very high capacity
- High speed
- Can leverage off existing network
- Very demanding geometry leading to high construction costs
- Creates severance when at surface level
For Airport rail, the capacity requirement of heavy rail wasn’t really a factor, due to relatively low projected passenger volumes – around 2,000 southbound trips in the morning peak in 2046 (compared to around 10,000 peak trips coming over the Harbour Bridge today in the morning peak):
While I think actual use will be much higher than this (models tend to substantially under-estimate future public transport use) it will still be well within the capacity capabilities of other modes like light rail. Therefore, the comparison really came down to a speed vs cost trade-off, with the high cost of serving heavy rail’s much more demanding geometry making this trade-off clearly fall in favour of light-rail.
The high costs of serving heavy rail’s demanding geometry means that heavy rail is most likely to “stack up” as the best option when we’re looking at a corridor with extremely high demand (i.e. beyond what might be able to be catered for through other modes) or where we can utilise the existing network.
North Shore rapid transit is potentially an example of a corridor which is likely to have very high demand in the future – because it is the only connection between a very large part of Auckland to the north, and the rest of the region. Early work a few years back suggested heavy rail as the preferred option, but more recently this appears to have shifted – illustrated by ATAP’s strategic PT network map linking North Shore rapid transit into the proposed Dominion Road LRT line. I know Auckland Transport are currently looking at different rapid transit options to serve the North Shore once the Northern Busway hits its capacity limits. I suspect the main question will be the trade-off between the extra capacity you get from heavy rail against the much higher costs of having to regrade the busway, along with the challenge of how it would link into the rest of the public transport system.
Importantly, even if the CRL does “complete” the heavy rail network and we don’t see major new lines in the future, there’s major upgrade of the network we have that will be required over time. Most obviously this is to separate passenger and freight services, but over time I see the need to separate local and express passenger trains – especially as the southern greenfield area grows. Therefore, ATAP’s $3 billion 30 year rail programme is almost certainly on the light-side of likely future investment in the heavy rail network in Auckland.
Auckland Transport have published a new version of their airport rail video, essentially stripping out the heavy rail parts while also adding a little bit more detail about the airport.
Perhaps one of the more interesting aspects is it shows a bit of how light rail would get through Onehunga. It appears the plan is to elevate the light rail line over Neilson St right where AT are about to remove the bridge that lifts the road over the rail corridor.
Every time rail to the airport is discussed, here or in other places, there are a number of people who question AT’s decision to use Light Rail to connect to the airport. The biggest complaints/misconceptions I’ve seen against the idea of using light rail to the airport are:
- Light rail is slower – especially on Dominion Rd with lots of stops
- That it will be like Melbourne mixed traffic
- Light rail doesn’t have enough capacity
- It will mix with trips on Dominion Rd
- It’s light and so heavy must equal bigger and better
So let’s step through some of these and to do so, I’m going to use Seattle as an example. The reason for using Seattle is that its Link Light Rail has many characteristics that appear to be almost identical to what Auckland Transport is proposing.
First a little bit about the system.
Seattle has only recently started building its light rail system and the first section opened in July 2009. Since then there have been a couple of extensions, to the airport in the south (six months later) and just in March this year, a 5km, 2 station extension to the north. Further extensions in each direction are already under construction with other lines and extensions planned.
As of now the entire light rail system is just over 30km in length which is almost identical to the distance between Papakura and Britomart. It does have fewer stations though and outside of the city, much wider station spacing. The route is a mix of grade separated right of way with a mix of tunnels and bridges, median running and in the city centre it shares one tunnel with buses. Below is an image from Streetview showing Martin Luther King Jr Way which a 6.2km long section of median running and is similar to what we can expect along Dominion Rd. As you can see it is not mixed with traffic and the rail is separated from the road by a small kerb. Access across the tracks at intersections is controlled by lights.
The light rail vehicles used in Seattle are capable of speeds up to 105km/h which at maximum is only 5km slower than our heavy rail trains are capable of, and which ours don’t often get close to achieving in normal service. Seattle has some fairly lengthy sections which over which I imagine it is able to make the most of it’s speed. That means it only takes about 44 minutes to travel the 30km for an impressive average speed of just over 40km/h. That is about the same average speed as the Eastern line from Manukau but considerably faster on average than the Southern, Onehunga and Western lines, the latter two average less than 30km.h.
Even if you exclude the section from the Airport to Rainier Beach and from Westlake to the University of Washington, the system achieves similar average speeds to our network.
Obviously our existing trains need to be faster but that is a discussion for a separate post. What is clear is that at the very least, it is possible to get light rail up to a similar speed as what we’re achieving now with our rail network.
To achieve the times Auckland Transport claim, LRT would only have to average 30km per hour, the same as being achieved on the Rainier Beach to Westlake section. With AT planning to create a corridor like shown above (but with a single traffic lane instead of two), that should be possible. There’ll be no light rail mixing with cars and also no stopping ever few hundred metres like many buses and many traditional tram networks such as Melbourne do.
It’s all very well saying that heavy rail has more capacity but just because you can build a rail line capable of running trains with a capacity for 1,000 people every 90 seconds, it doesn’t mean you should. It is very expensive both to build and run so most cities only do it if they absolutely need to. Better to build enough capacity for what you’re going to need (plus a bit of redundancy).
As we know, AT are planning on using up to 66m long light rail vehicles (two 33m coupled together) that can carry up to 450 people running every 5 minutes. Looking over at Seattle, they have 29m long vehicles that can carry around 200 people running at up to every 6 minutes in the peak. They too can couple vehicles together and until recently were limited to joining two trains together but their system allows for up to four to be coupled. Four vehicles connected together would be around 116m long and carry up to 800 people – more than one of our 6-car trains are designed to carry (ours carry 750 people). Given the technology is obviously already available, there doesn’t seem to be a technical reason why we eventually couldn’t see longer light rail trains here – assuming we designed for the possibility.
Another way of looking at capacity to see how it’s performing. Sound Transit who run the system publish ridership data monthly. The opening of the extension to the University of Washington in March has seen ridership soar at up to a staggering 83% compared to the same month a year prior. That means over the last few months, this single LRT line is carrying more than Auckland’s entire rail network combined. The results suggest that by the time the extension has been operative for a year that their system will be carrying 20 million+ trips a year. Seattle’s weekday numbers are about the same as what we have but they do much better on weekends, something we’ll hopefully see the new network improve.
On both speed and capacity, the example for Seattle shows that Light Rail can be every bit as good as our current heavy rail system. For me the key is not the name of the mode but how it’s designed. The pressure that needs to be applied to Auckland Transport, the council and the government is to provide the funding needed as soon as possible and to ensure that it’s implemented to the level advertised in the video above (or better). Light or heavy, it’s still rail to the airport.
Within the Auckland Transport Alignment Process Interim Report is the news that the six lane highway across the harbour as currently planned, the Additional Harbour Crossing, just doesn’t work, and is now at least mortally wounded, if not actually dead.
Clearly a total re-think of ways to serve the growing movement demand between the city and the north east is required. In January the Waterview connection and the supersizing of the North Western will open, and later a new interchange between SH 18 and SH 1 will complete the next road connections between the upper harbour and the wider city.
Additionally the SkyPath, SeaPath, and improvements to ferry services will also be added to the mix for the inner harbour, for the Active modes.
The great missing piece in the movement jigsaw for this part of the city [as elsewhere] is a Rapid Transit connection across the harbour and through the Shore. The case for the next major connection across the harbour utilising the high capacity, smaller foot print, and traffic reduction outcomes of Rapid Transit is now all but made.
Here I want to explore the options for an actually successful harbour crossing, particularly in light of recent announcements about the Mangere/Airport RTN, but also because of the need for a viable near term system that fits into the longer term needs of our growing city. I can’t emphasise this enough; for a system to actually get funded and built it surely must fit both those criteria, and that is not easy.
What follows is an exploration of possibilities done with a fairly broad brush; a high altitude view, with a lot of scope for variation in detail.
In 2012 I wrote a couple of speculative posts proposing the Shore Line as an extension of our current rail network. Here and here. I was interested in looking beyond the CRL to examine future improvements to the Shore and through Mangere to the Airport. In particular in offering an Albany to Airport one seat ride through an east-west CRL II type project, like this:
CITY CENTRE ‘The Cross’
While there is some elegance to these proposals [and some problems] it is clear that I started from an unexpressed assumption that all future rail systems would be extensions of the current network. This is no longer my view primarily because our current network has very firm structural upper limits for train movements, that means at some point it becomes limiting to try to add ever more arms to this body. Adding an additional high demand area like the North Shore will bring those limits forward, especially to hard to expand pinch points like Newmarket Station and Junction. Remembering too that freight movements are growing on parts of the network too. This isn’t to criticise our re-born urban rail system, it will remain the vital core of Auckland’s RTN, growing quickly post CRL to 50m trips pa. and beyond. But rather to recognise that it needs to be free to serve these core roles, supported by other existing and enhanced networks, and some new ones.
I also suspect that the required crosstown tunnel would be prohibitively expensive, especially when combined with a cross harbour one. Together these costs could be sufficiently high to kill the plan.
Instead, adding a new and complimentary network, making connections by transfer at interchange stations, adds resilience as well as more capacity, in that problems on one network won’t affect the other. This also allows us to tailor the next network to our current demands and utilise all the latest technology and thinking without needing to accommodate it to the physical parameters of the existing system [freedom from the ‘happenstance of yore’].
On the assumption that the current Busway can be relatively easily converted to Light Rail, the obvious opportunity is leverage off AT’s Light Rail plans for a Queen St-Dominion Rd system through Mangere to the Airport so that this:
becomes this, an idea we have explored in the past:
So the return of the highly desirable one-seat ride from Albany to the Airport, on a high catchment spine; the A-Train, but this time via Light Rail, on a combination of higher speed grade separate paths, and high access street running. The advantages and disadvantages of these conditions have been debated at length on previous posts, what I want to examine here are future network possibilities of such a system, because networks are always greater than their parts. However it is worth a visit to this analysis of the recent addition of Light Rail to Paris’ Transit mix on this very issue; degrees of separation, I guess you could call it. Basically it concludes that while it is always better to strive for as much separate running as possible, this needs to be balanced against both capital cost and quality of access. And especially the quantity and quality of the transfer nodes with other major Transit Networks.
It takes just a few seconds looking at the RATP map to see why the Paris trams are so useful. In Paris’s hub-and-spoke transit network, they are the rim of the wheel, connecting the ends of Metro and RER lines in far-flung parts of the region. All nine lines offer at least two stations that connect to other modes of transit. Some offer many more:
||No. of transfers
||No. of total stations
||Pct. of stations with transfers
So returning to Auckland and the proposed A Line we can see that while it would be a great complement to our existing fast growing Rail Network, and likely further RTN extensions including AMETI, and the North-Western, it still only connects with it at the four stations indicated with blue dots above. However the possibilities for leveraging off this system to create a second route with a rich abundance of connectedness:
The western section carries along the grade separate SH20 alignment to a new station at Owairaka, then continues to Mt Albert Station, Unitec, and to the future RTN station at Pt Chev on the North-Western line, on-street [The RTN connections are why I prefer this possible extension over one to the metro-centre of New Lynn]. The southern to Puhinui Station and the Manukau City Interchange Station down Lambie Dr, again mostly on its own alignment.
Which of course can be extended to include AMETI:
The simplest idea would be to run these as two overlapping lines A and B, giving the Airport and Mangere great connectivity west, south, north, and east. Direct to the City Centre and great connectivity with every branch of the RTN, including of course the Onehunga line. Or say three lines all converging on the Airport. Such a system is also highly stageable, and you all can haggle over your favourite technology for each part….
The key principle though must be future proofing for upgrades. I think it is vital, for example, that the harbour crossing, if it is to be Light Rail, is built so it can take Light Metro for the time in the future that the demand from the Shore is high enough to justify a tunnel from Wynyard to Aotea Station and the option of implementing a fully driverless system as then it would be 100% grade separate. I’m sure some would like to start straight off with such a system, but I think it is clear that designing systems that can grow with the city is the only viable way forward.
Without trying to put a date on it, below is a pretty good integrated RTN future to aim for:
Rail running at 5min frequencies on the outer lines so a train every 2.5 mins in the CRL and other places [Red and Green]
LRT also at varying frequencies depending on place, perhaps even two routes from Wynyard to the city
More Ferries, Rapid Bus on Gt North Rd and the NW and across the Upper Harbour, although especially from Pt Chev to the city could be LRT too.
When or whether parts of this are Buses or Light Rail, are not so much my focus but rather getting the coverage optimised, and the routes protected.
No doubt it will change but here’s a potential version. Discuss:
A lot of debate over the last week has focused on rail to the airport and Auckland Transport/NZTA’s decision to dump heavy rail as an option, primarily due to costs but also because they believe light rail could deliver similar benefits. As has happened pretty much every time in the past when discussing this topic, the focus of many commentators here and across the media spectrum has been squarely on connecting the airport and the CBD. That’s somewhat understandable given both are significant destinations but when focusing on a singular use outcome it naturally results in a misunderstanding of what is trying to be achieved and people trying to come up with alternative ways to achieve that.
The two prime examples of this is the suggestion that we need to have a non-stop express service between the two main destinations and that we could save money but just building a connection across open land from Puhinui to the airport. The latter was even the subject of the herald editorial on Friday.
When most of us look at a map of Auckland’s railways, a spur line to the airport appears obvious and easy. The main line south runs through Wiri and its Puhinui Station is about 5km from the air terminals. A track could be laid through largely open land to the airport perimeter. What could be simpler?
Alas, simple solutions seem not to be welcome in the organisations charged with planning Auckland’s transport.
They are looking at the wrong route
While a faster and/or a cheaper connection would be nice for those just going to the CBD, the numbers doing that exact trip are never likely to be higher enough to justify the scale of investment that rail requires. More importantly, the issue with both of those positions is they ignore one of the key strategic goals that are trying to be achieved, to improve public transport for those that live and work in the Southwest and this is a goal regardless of the mode used.
Currently the Southwest is estimated to be home to close to 50,000 people and growing to an estimated 66,000 by 2043. Some of that growth is already underway with developments like the Walmsley Rd SHA set to deliver around 1,600 new dwellings which is likely enough to house another 5,000 people. There are also around 31,000 jobs in this area of which about 12,000 are at the airport itself with the rest in the industrial areas to the north or in and around Mangere and Mangere Bridge. The airport company expect to employment numbers around the airport will increase significantly as more land is developed. That will help to make
Whichever way you look at it, that’s a lot of people and a lot of jobs and it would be short-sighted and unfair not to give them some form of quality PT option – this equally applies to other parts of the Auckland urban area too.
Looking at Stats NZ commuter view for two of the area units included in the figures above, we can see that the biggest single destination (outside of working within the same area unit) was working in the Mangere South area which includes the Airport and the Ascot/Montgomerie Industrial area. But while not to the same individual level, there are a number of people who also travel north to work in other parts of the city.
Workers at the Airport itself come from all over the region, a lot from the east but also a significant numbers the north. The numbers from the east will be partially why AT have said they’ll start the early stages of investigation into an RTN route between Botany, Manukau and the airport.
So rail to the airport is actually about serving three separate markets
- Travellers themselves
- People working around the Airport and nearby employment centres (this is likely to be the biggest share of potential users)
- People living in Mangere and its surrounding suburbs
Spending the kind of money needed to build a rail line to serve any one of these uses is almost certainly not going to be able to stack up but with all three uses combined it can. What’s more from a PT perspective a Southwest line likely has a couple of big advantages that could make it one of the busiest on the network. Compared to our existing RTN lines, having very strong anchors at each end of the line in the form of the city and the airport will help get good bi-directional usage. Added to that the inherent nature of airport arrivals and departures throughout the day would help drive off-peak usage. As such frequencies are likely to need to be kept fairly high which also benefits others on the route.
Like how some people have incorrectly assumed that because the CRL is in the city, it’s all about trains going around the city, rail to the airport is assumed just to be about people going to the airport but as I’ve discussed it’s really about serving the entire Southwest. Formally the project is called Southwest Multimodal Airport Rail Transit (SMART) but that’s a name that will never catch on. People understand the term Airport Rail and also like the CRL, some people probably won’t realise/understand just what it is trying to do till it actually opens.
Following on from my post a few days ago on light rail being preferred to the airport – which has been one of the most commented on that we’ve ever had – by far the most common concern is around the speed of light rail, particularly on the section along Dominion Rd.
I’ve taken a look in the past at what other cities who have built similar light rail systems to what AT are proposing and I found that a number of them are capable of the speeds suggested. But of course they aren’t Auckland so I thought I’d take a quick look at some of the things we know that AT are proposing that will help ensure light rail will be quick and reliable along this important corridor.
Fewer stops and more direct route
Buses along Dominion Rd between the Southwestern motorway and the centre town have almost 30 stops to pass along the way. There are of course bus lanes along a lot of the route but they stop short at key intersections which can cause delays. Before light rail came along, AT had planned to lengthen these bus lanes right to the intersection to help speed up buses further. The current timetable shows travel times between Denbigh Ave close to the motorway and the city taking between about 23 minutes and 41 minutes depending on the time of day.
With light rail Auckland Transport plan to significantly reduce the number of stops along the route with just eight on Dominion Rd itself and only 10 to get to the same point in town. Of course one down side to some residents is it means they may have to walk further to get to a stop. For light rail it appears they’ve effectively picked one stop in the main centres along the route with intermediate stops between them.
You can see the difference in the two in the map below. Fewer stops means vehicles can travel faster as they’re not constantly accelerating or braking.
Buses can also suffer from dwell time issues from boarding and alighting passengers. It is possible to address some of these, such as restricting cash payments, allowing all door boarding which could speed up buses a bit but off line ticketing and fast boarding are a fairly standard feature of light rail so provided that AT implement it properly that will help compared to the current situation people compare to.
In addition to fewer stops, you can see from the map above that light rail takes a more direct route to the city and so has fewer intersections to negotiate.
Buses currently are at the mercy of traffic lights and at the big intersections with long cycle times this can slow them down and cause buses to bunch. When bus frequencies get too high it results in there almost always being buses waiting to get through lights, which is often a leading cause of them bunching and is not good for operations or passengers.
One reasons we heard AT were for looking at light rail on Dominion Rd in the first place was that it allowed fewer but much larger vehicles to run. The advantage of that is it allows for signal priority to be effective and so depending on how it is set up, it could mean the light rail never has to stop at Intersections other than at its stations. Again that could end up being a significant time saving.
On a related note, we know that light rail will be able to skip one major intersection with AT have suggesting that they will tunnel under the K Rd ridgeline as part of building that part of the line. I believe this is mainly for operational reasons – removing a steep part of the hill – but it will also benefit travel times.
Centre running protected route
Running light rail down the centre of Dominion Rd means it won’t get held up by cars turning left into side streets or driveways, parking to run into the shops or drop someone off/pick them up. Cars would only be able to turn right at specific intersections and not when a light rail vehicle is around. It is also common for the light rail corridor to be protected by a raised kerb to prevent cars from accessing the tracks or using them as a median, in much the same way that kerbs are used to stop people driving in cycle lanes. Examples include the Gold Coast as shown below and Seattle.
A raised kerb can also be seen in some of the concept images AT have released in the past such as this on of Ian McKinnion Dr
When you combine all of these elements it means that light rail is able to travel down Dominion Rd pretty much completely unimpeded by other traffic and only needing to stop a few times along the way. The speed limit for light rail would almost certainly still be 50km/h but even if it could average half that, it could travel the 7km between the centre of town and SH20 in just 17 minutes. As a quick comparison, in the same timeframe leaving from Britomart would be at about Ellerslie – although admittedly we expect AT go get that time sped up a bit.
Once the route reaches SH20 the LRT route appears to be almost completely separate from traffic with the exception of a small section in Onehunga and so for most of it could easily travel at up to 100km/h if the vehicles and tracks were designed to do so – and that has been suggested by AT in the documents they’ve produced so far.
This gives me confidence that for LRT at least, the times AT have suggested are realistic but I’d add that a lot depends on just how well they implement everything.
A big day yesterday with Auckland Transport officially deciding to drop the option of heavy rail to the airport in favour of light rail (LRT) or perhaps even buses as had been foreshadowed in the Herald in the morning but also hinted at for some time from previous information released by AT.
Yesterday afternoon they released the previously confidential paper that was used to justify the decision which has thrown up a few interesting details.
In the end the biggest nail in the coffin for heavy rail has ended up being the cost which is now estimated at $2.6 to $3 billion. Being even more expensive than the CRL and with fewer benefits – after-all the CRL improves the entire rail network – it is always going to be hard sell and in the end AT and the NZTA have said it simply offered “low value for money” with a Benefit Cost Ratio of 0.37-0.64. As a comparison they estimate LRT could have similar or even greater overall benefits – I’ll get to that soon – but come in at less than half the price at an estimated $1.2-1.3 billion giving it a BCR of 1.11-1.72. That figure seems to be an improvement on earlier information such as the video that was released at the beginning of the year.
The biggest issue with the LRT option though is it assumes that LRT will already be in place along Dominion Rd and that this is therefore just an extension. The issue with that is so far there is no agreement from the NZTA or the government that the Dominion Rd route will be supported – although the ATAP report last week seems to confirm something more than just more buses will be needed. But even if the cost of LRT along Dominion Rd (estimated at $1 billion) was included in, it still comes in cheaper than heavy rail and would have even higher benefits. The LRT option also benefits from providing new connections on the isthmus to the South West so represents a greater expansion of the rapid transit network. A comparison between the accessibility of the two is below.
The estimated costs and benefits discounted to 2015 $ are shown below.
On the costs, one expensive part of heavy rail is the need to also upgrade the Onehunga line and deal with the level crossings. AT say they considered three options for this, a long New Lynn style trench, realignment via Mt Smart and elevated rail with costs ranging from $458-578 million. Later it appears a low cost option of closing two of the level crossings and barriers which would cost $155 million and that was used in the Indicative Business Case but AT are also concerned not grade separating the crossings would cause traffic issues.
Within the airport they also eventually came up with a more direct route shown in blue but that requires bored tunnels ~20-25m deep and adds to the costs listed above and is what pushes the cost to $3 billion. There are other issues too such as with the terminal station under the airport, AT would have to pay for it when the Airport wanted to upgrade the terminal which is likely to be sooner than when AT have LRT scheduled and that would add $100 million to ATs already tight budget requirements.
The paper also addresses many of the issues that have been raised on here and in other places in the past.
One such issue is the travel time and people have in the past questioned suggestions that LRT could be the same or even faster than heavy rail. They say travel times were worked out using several models taking into account issues such as LRT speed down Dominion Rd, the acceleration/deceleration possible, station dwell times, specific track lengths, curves and gradients along with how fast vehicles could travel over them. They say that because of the heavy rail geometries required there is only a few locations where HR can hit top speed.
All of that resulted in the range of times shown below from both Aotea and Britomart with LRT coming out on top from Aotea which is centre of the CBD.
One particular area where LRT is much faster is in and around Onehunga, presumably the section over the harbour where the line has to be elevated above Neilson St then again over the East-West mega road before dropping under the motorway bridge as shown below.
The big concern for me with travel times is that it comes down to how well they’re implemented and so far AT haven’t proven themselves good at at that. This is evidenced by how poor AT have seemingly been so far at addressing our slow trains.
Another issue that has been raised before is the capacity of LRT. What needs to be remembered is that even before this idea came along, AT aren’t planning on dinky little streetcars running around the suburbs but are large, long and potentially quite fast. As AT have said in the past they could be up to 66m long carrying over 400 passengers each which is on par with our current electric trains.
So over a two-hour morning peak with services every five minutes LRT could be moving up to 10,000 people an hour in each direction which is about the same number of people who currently arrive at Britomart each morning and nothing to sneeze at. They say the model estimates that with LRT around 3,500-7,500 people would cross the Manakau Harbour each morning with around 5,300-6,900 using the section from Onehunga to Dominion Rd. The biggest concern would be that if it was too popular it might restrict capacity on Dominion Rd but in many ways that would be a nice problem to have.
One interesting aspect of the paper is a discussion on the opportunity cost of Heavy Rail. While it doesn’t happen in reality, they say the hypothetical situation of taking the money saved by using LRT would be enough to also build a light rail link from the Airport all the way to Botany – whereby it could link with the proposed AMETI busway. I don’t think that this route is a high priority to sink another $1b+ into just yet compared to other PT routes such as the NW-busway but it is interesting to ponder long term as part of a wider LRT network.
Here are the recommendations the board were provided which I assume they accepted. Given the capacity that has been suggested is needed and that we know there are already issues with bus capacity in the city I can’t see a bus option stacking up other than for some short term improvements.
- That Management discount heavy rail to the airport from any further option development due to its poor value for money proposition;
- Instructs Management to:
- a) Develop a bus based high capacity mode to the same level of detail as the LRT option to allow a value for money comparison with the LRT option and submit this to ATAP for consideration;
- b) Refine the LRT option further to address the high risk issues as articulated in this paper;
- c) Report back to the Board on the findings of the bus based high capacity mode and LRT comparison.
- d) Progress with route protection for bus / light rail, not heavy rail;
- e) Align the SMART and CAP business cases to enable the consideration of an integrated public transport system between the city centre and the airport
- f) Progress the business case development of the RTN route between Botany, Manukau and the airport and align this with NZTA’s business case development for SH20B.
The decision between light and heavy rail will never please everyone but personally I’d rather a light rail connection that actually happened than a heavy rail one that never did. A bit of a case of don’t let perfect be the enemy of good but in this case it’s not clear that heavy rail is perfect. I also don’t think it’s realistic to think that it’s just a political change away from the decision changing like some have suggested. I personally can’t see other political parties agreeing to fund something with such a poor business case given the alternative option that now exists. We’ve been critical of road projects that have poor economic cases so it’s only fair that we do the same with PT projects (although do wish these road projects were subject to greater levels of scrutiny – looking at you East-West).
What is needed though is to simply get on with things. We can’t afford to wait another 15+ years for this to be built, we need to be getting on with it. Compared to some of the motorway projects which now get accelerated rapidly, major PT projects like this seem to languish in the back of the planning departments for years, if not decades. This needs to change if Auckland is to become a much more liveable city.
One of the main concerns I’ve seen raised about the idea of Light Rail to the airport has been the speed. In particular, that light rail is too slow in comparison to heavy rail, especially along the Dominion Rd section where it is also suggested it could also be held up by traffic. After I wrote about it last week Auckland Transport updated their website with some more details of the project – mostly with details from the video they’ve created but also with new a new travel time comparison as they say the times in the video are now out of date. The updated travel times are shown in the table below and as you can see are even more favourable to light rail, putting it just five minutes slower than heavy rail from Britomart and equal in travel time from Aotea.
|Britomart (downtown) to airport
|Aotea (new City Rail Link station) to airport
In the blog and other places where discussion about the idea has occurred I’ve seen people questioning the travel times claimed by Auckland Transport. If these timings are accurate I think it makes a significant difference as to the viability of light rail as an option, not just to the airport but potentially for other applications such as to the North Shore, East Auckland and the North West. With this post I thought I would examine the light rail timings in more detail to see if they stack up.
As a reminder this is the route Auckland Transport suggest.
From Britomart to SH20 via Dominion Rd the light rail route is fairly straight and AT say it would travel down the centre of the road in dedicated lanes. They also say light rail would have priority at intersections along the way so vehicles would not often need to stop unless doing so at a station. AT reaching SH20 it would then follow the motorway down to Onehunga for a short section on street before a dedicated section from there to the Airport. In total this route is around 22.6km and at 44 minutes giving an average of 31km/h. As a comparison our current rail lines achieve the following speeds (although AT do need to get them faster):
- Western Line – 27.2km – 55 minutes travel time which is 30km/h
- Southern Line – 33.1km – 56 minutes travel time which is 33km/h
- Eastern Line – 25km – 37 minutes travel time which is 41km/h
- Onehunga Line – 12.8km – 27 minutes travel time which is 28km/h
To examine the speeds suggested by AT I thought the best option would be to conduct a few case studies to see what other cities manage to achieve. Below I look at five cities that are not too dissimilar to Auckland that have working light rail systems. The travel times they achieve are based on published timetables.
Calgary’s C-Train system is one of most used light rail networks in North America with over 330k trips on an average weekday, about six times what Auckland’s current rail network achieves. The system has two lines that share a central section though the CBD, the Red line is 33km and the blue line 25.7km.
The lines generally run down either in the centre of the road or on one side and are fenced off from traffic and people however they also cross through many intersections at grade. On some intersections where the light rail route changes direction/arterial it is running on they use short underpasses so it avoids the intersection completely. In short it’s a largely dedicated corridor which is not to dissimilar to what we would expect to see in Auckland.
Calgary’s light rail vehicles are capable of speeds up to 80km/h and below is how long each line is and how much time the timetable suggests a trip the entire length will take.
- Red Line – 33km – 59 minutes travel time which is 34km/h
- Blue Line – 25.7km – 46 minutes travel time which is 34km/h
Seattle has two light rail lines, one a short shuttle in Tecoma but the main one the Central Link, is a 25.1km line from the Airport to the city that opened in mid-2009. Much of the route is elevated, in tunnels or offline (alongside a freeway) however there are a few significant sections where the route travels down the centre of a road corridor separated from traffic only by a small concrete kerb.
There are 13 stations all up. In the city station spacing is about every 600m but as it gets into the suburbs it expands and becomes more like heavy rail. There is also a 9km section with no stations which would help speeds.
Seattle uses two 29m long light rail vehicles that are coupled together able to carry a combined 400 people – they eventually plan to couple up to four vehicles together. They have a top speed of 105km/h which would be useful on the long spaced out sections.
According to the timetable a trip from the along the line would takes around 37 minutes from end to end. Over the 25km that’s an impressive average of 41km/h – quite a bit faster than all but the Manukau line on our rail network. The single line carries close to 12 million trips a year – what Auckland’s rail system carried just over a year ago but remember it’s only been open since 2009.
Salt Lake City
Salt Lake City runs a three-line light rail system through city streets in dedicated lanes and from what I can tell there is no grade separation. The system first opened in 1999 and generally tracks run down the centre of streets separated from general traffic by a small kerb. Unlike the examples above the system doesn’t have any grade separation at intersections and many side roads cross the tracks along the way. It uses signal priority to achieve a mostly uninterrupted service along the routes. The Blue Line is 31.1km, Red Line 38.1km and Green Line 24.2km.
The system uses similar vehicles to what is used in Calgary and like Calgary they have a top speed of 80km/h. The system currently carries 18-19 million trips a year. According to the timetables the three lines take the following length of time to travel end to end and following that is their average speed.
- Blue Line – 31.1km – 51 minutes – 37km/h
- Red Line – 38.1 – 59 minutes – 39km/h
- Green Line – 24.2 – 46 minutes – 32km/h
So despite not having the grade separation that the systems above have the system still manages to achieve some pretty good speeds.
Houston maybe a famous for its sprawl and massive motorways but it also happens to have an increasingly used light rail line. Its Red Line opened in 2004 was extended in late 2013 to a total of 20.6km. Two new lines opened in May last year but for this I’ll focus on the red line which carries the vast majority of over 16 million light rail trips. The system runs largely on street level in dedicated lanes down the centre of the road separated from traffic with concrete kerbs. Following the line via Google Maps shows an extensive numbers of roads that cross the tracks at points along the journey and it’s not clear if there is any signal priority and this affects the speed.
Houston’s Light Rail system includes this section through a water feature in the CBD
The system uses light rail vehicles capable of 106km/h but given the station spacing and intersections I doubt they ever get close to that. Trips along the 20.6km line take around 55 minutes giving it an average of 22km/h – a step down from the cities above.
Lastly one of the closest to home is on the Gold Coast – which I experienced myself just a few months ago. The vehicles are 44m long and can carry 309 passengers and have a top speed of 70km/h
The system is 13km long and runs in a dedicated corridor which is mostly down the centre of streets and at most intersections it has signal priority. Importantly through areas such as through Surfers Paradise it seemed to be limited in speed to around 30-40km/h for extensive sections and that limits the overall speed of services. At 37 minutes from end to end it also happens to have the slowest average of the examples at just 21km/h.
There are of course many other systems that could be examined but what is clear from the ones above is that there are a range of systems and a range in how those systems are implemented. The systems that tend to have a mix of infrastructure such as dedicated corridors and sections of on street running seem to do fairly well and those systems are also likely to be the most similar to what Auckland Transport are proposing. As such, assuming AT design the system right then a 44-minute transit time from Britomart to the airport or 41 minutes from Aotea actually seems reasonable. Further I would have expected that they’ve calculated it far more accurately that I have.
Perhaps speed isn’t quite the issue that some have made out and we can save $1.2 billion by using light rail to the airport. That might also then let us extend the light rail somewhere else such as the North, Northwest or East.
The topic of rail to the airport has been getting an airing in the last few weeks after the Herald finally published some information we originally posted back in August – that AT are considering using light rail to connect the airport with the city rather than extending the heavy rail network. The need for a decision on what mode to eventually use is being hastened as the airport company need it by the middle of the year so they can finalise their future development plans. We’ve got an exclusive video showing what the heavy and light rail options.
Before diving into the details I want to make a couple of comments.
- Unfortunately much of discussion I’ve seen in the wake of the articles has fallen into the trap of being too focused on the technology rather than the outcome and despite the focus there appears to be a general misunderstanding of the technology involved. By that I mean there seems to be an assumption that light rail is a low strength version of heavy rail, a bit like light beer vs normal beer. In reality it all depends on how each technology is implemented. There are light rail systems that are faster and have greater capacity than what our heavy rail system will have even with the CRL.
- I’ll state upfront that my preference remains that the connection be by heavy rail. I think the time competitiveness it offers is probably being undervalued by AT compared to the other factors. I also see it as a nice balance to the operating patterns proposed post CRL. In effect I see it as completing the heavy rail network.
- AT have already decided that the connection to the airport will be from Onehunga linking in Mangere Bridge and Mangere. Onehunga is also important is has been chosen by Panuku Development Auckland as one of the key areas they’ll be focusing on and so improving connections from their in either direction makes a lot of sense. The alternatives of connecting via Otahuhu have been ruled out due to the amount of property purchase that would be needed and the Puhinui option would require difficult (i.e. expensive) connections and would be a challenge operationally.
So why are AT even thinking about light rail. The simple answer is the cost. AT say that they now believe it would cost around $2 billion to build a heavy rail line to the Airport. Light rail is cheaper and easier to build with AT have estimating it at around $1 billion – but importantly that is from the end of the proposed line down Dominion Rd. AT seem pretty confident they’ll get that line signed off but whether that turns into a reality remains to be seen. However even if you take the $1 billion cost for a light rail line down Dominion Rd into account you’re still looking at a $2 billion heavy rail line serving just the southwest or a $2 billion light rail line that serves the southwest and the central isthmus. As such, on a cost/benefit comparison the latter is going to look stronger and why AT is interested.
To help show some of the differences between the two options AT have put together a fairly detailed video of them which is at the end of the post. I first saw this over a month ago and AT have now let me post show it. It was included as a part of the presentation that inspired this post. There is no narration to explain what is going on so I’ve explained it below. I understand AT are working on a narrated version for wider public use.
The video starts off showing the potential travel times between the city and the airport. Along with the time it takes is the potential variability and in that regard the rail options offer more reliable trip times than buses and much more reliability than driving. As I understand it the reason light rail is more reliable than buses is that it will have effectively an exclusive right of way down Dominion Rd combined with signal pre-emption meaning it will rarely need to stop at lights. That it might need to stop has been an issue raised against using light rail and is a case of perhaps AT not explaining clearly enough just how high the quality is that they’re proposing.
It’s also worth noting that the travel times suggested are more in line with what we’ve posted before and not as close as the herald has suggested, around 35 minutes for heavy rail and 47 minutes for light rail (herald suggested 39 and 44 respectively).
The video shows the heavy rail option. It involves double tracking the Onehunga Line and as I understand, grade separating many of the crossings. It then follow SH2o and 20A with stations at Mangere Bridge and Mangere and then crucially it would loop away from SH20 before getting to the airport itself. This is important later in the post.
Light rail would travel from Dominion Rd alongside SH20 to Onehunga and then on the same route to the airport with the exception of it staying with SH20 the entire way. In addition to what’s proposed above there would be stations at Hillsborough, Favona, Ascot and the Airport’s growing office park. From the end of Dominion Rd the 15km line to the airport would be almost completely grade separated and so would have similar performance to heavy rail. That makes the line roughly 1/3 on street and 2/3rds off street. I’m not quite sure why there couldn’t be heavy rail stations at Favona and Ascot but there definitely couldn’t be at the airport business park as the route avoids that area. The extra stations help increase the catchment in favour of light rail.
The video gets more interesting once it zooms in to show how the lines would look. Between Onehunga and the SH20/A motorway junction both heavy and light rail have virtually identical infrastructure. A bridge would span the proposed East-West Link that then passes under the motorway bridges to the western side of the motorway. From there it travels alongside the motorway rising over the Walmsley Rd/Corronation Dr interchange before rising again above SH2o. It’s from here that the differences really begin.
After crossing above the motorway the grades required for heavy rail mean there isn’t enough space to get back to ground level before reaching Bader Dr so the Heavy Rail option is elevated above it to the Mangere Station.
The same issue then occurs with Kirkbride Rd and the trench currently being built meaning the line then has to pass over Kirkbride Rd. I understand the trench is about two times too steep for heavy rail.
South of Kirkbride Rd the line returns to ground level but has to divert away from the road before reaching the airport. As I understand it all transport options will need to drop below the second runway that is proposed and again the grades mean the rail line can’t follow the road.
Lastly for some reason it’s been decided that the heavy rail line and the station has to be underground at the Airport, this obviously pushes up the cost of building the line. I also understand it has been proposed to be located a little further away from the terminal than the light rail stop at street level and the extra walking time has even been factored into the travel time calculations. Given the airport is planning a fairly blank slate redo of the road network all around the airport and building an new terminal extension, it seems strange that a heavy rail route and station at ground level couldn’t be easily integrated into masterplan.
Light rail is able to handle steeper grades and sharper curves than heavy rail is and as such is able to get back to ground level and go under Bader Dr. This means a light rail station would be located within the median of the motorway – and hopefully with some good noise protection. You may notice the station planned is much less glamorous than its heavy rail counterpart – presumably making it much cheaper.
South of the line is able to stay within the motorway median and pass through the trench currently being built and for which AT have paid $29 million to make 3.5m wider so it can accommodate rail. I’m sure visually for locals and from a consenting perspective this will be an easier sell than the elevated heavy rail option. Light rail is then able to stay with road all the way to the terminal again helping to keep it cheaper. It seems the main benefit of LRT is it’s just that much easier to bend around existing infrastructure.
AT then give a comparison between the two modes showing what they think is best. This is similar but not exactly the same as one shown in the August post. For one thing it lists the benefit cost ratio of each option suggesting that some likely early economic evaluation has already taken place. As you can see the light rail option is quite a bit higher than the heavy rail option although it is only hovering around 1 – much like many of the RoNS.
Here is the video.
The two biggest arguments against light rail seem to be the speed and capacity. I think the speed one is warranted to a large degree as I suspect offering a rail option that was almost always faster than any road option would have a huge impact on what mode people choose to use.
As for capacity I suspect that one is a bit less valid – although not completely. AT are suggesting some very heavy duty light rail vehicles capable of carrying up to 450 people each and on a route like Dominion Rd they would be running fairly frequently, potentially every few minutes if places like Melbourne are anything to go by. That is a considerable step up the capacity of buses along there now, although looking at the comparison table above they seem to be underselling it as 1,630 passengers an hour works out to only four vehicles an hour each way. The question is whether the additional patronage generated by a southwest line would then result in issues along Dominion Rd which is busy enough as it is. It would be good for AT to cover that issue in more detail.
If the figures above are accurate it’s easy to see why AT are so interested in light rail. In the current political climate it would be impossible to every get a heavy rail option over the line, it’s just too expensive. Light rail appears to be far from completely terrible and actually has a chance. A case of don’t let perfect be the enemy of good? In saying that I do get the feeling that there’s a little bias going on. For example why aren’t there extra heavy rail stations at Favona and Ascot.
What do you think of the options?
Lastly regardless of the mode, if drivers are anything like the ones in the video I think rail will be a huge success – although perhaps that just represents reality.
Around two weeks ago AT gave a presentation to the Council’s Infrastructure committee which contained a lot of very interesting information about some of the major projects they’re working on. I also heard a segment of the presentation at a talk last week. I won’t cover everything in the presentation as much of the charts and maps are ones we’ve seen before that I found interesting.
The presentation starts by looking at Auckland’s expected population growth in comparison to the growth happening in the rest of NZ using some charts most will probably be familiar with. Just in case you aren’t they highlight that using the medium growth projections out to 2043 that more than half of all population growth will be in Auckland and that growth alone will equal be greater than the current population of Christchurch and its expected growth. What was interesting though was the chart below showing how Auckland has grown compared to the previous population projections and as you can see the projections keep being revised upwards. The 1996 projection estimated Auckland would hit 2 million people in 2063 but the 2013 one suggests it will now be 2033.
As mentioned the growth is comparable to the expected population in Christchurch and the image below shows the land area of all of the greenfield growth (blue) and Special Housing Areas (Orange) from across the region combined into one Christchurch sized mass – I’ve also seen a version comparing it to Hamilton with roughly a Hamilton sized growth occurring in the South, about a 2/3rds Hamilton in the North West and half a Hamilton in the North.
On the topic of growth this chart highlights just how much is expected to occur in the city centre – which is the CBD and fringe suburbs such as Grafton, Newmarket Parnell, Ponsonby etc. – compared to other parts of Auckland. I’m not quite sure where the boundaries for the other areas are but it’s also interesting to see the second biggest expected employment growth area is in the North West.
Moving on to some of the more interesting aspects of the presentation, there is a series of maps showing how the Rapid Transit Network will develop over the next 30 years. Now what does that presentation format remind you of? It’s great that AT are now starting to present the information this way as personally I think it makes it much easier for the general public to understand what’s proposed for their city.
One aspect you will notice is the access to the Airport. The map shows both heavy and light rail options as it has yet to be decided which one will be built. Accompanying the presentation was an animated video that showed the options in much more detail including what they would look like between Onehunga and Kirkbride Rd. This hasn’t yet been published so I’ve asked AT when that will happen as it was very interesting. I’ll discuss a little more about this later in the post. Also the more I look at it the more I think it seems natural for light rail to be extended over to the North Shore where it can then spread out again to provide greater coverage.
On light rail the presentation moved on to AT’s proposal for it on the isthmus. A lot of the justification for it is to reduce the number of buses in the city centre as some corridors like Wellesley St will have over 180 per hour in the peak direction based on current plans. We’ve shown these maps before but they’re worth repeating.s
And with LRT in place bus numbers reduce dramatically. One thing I am aware of is that the map below is not be entirely correct as I know the board have decided not to send LRT down to Quay St, instead it will stay on Customs St (and presumably travel down Fanshawe St).
It still leaves Wellesley St as a very busy bus corridor but allows more buses from other parts of the city not served by heavy or light rail. Thee impact of not building Light Rail is highlighted in this map showing that bus congestion in the city slows buses down reducing the number of people within a 45 minute trip of the city centre. Interestingly some of the worst affected areas are the North Shore which again suggests it’s probably worth looking at something like LRT to the shore to reduce the reliance on buses.
Note: the map shows that many of the ferry routes don’t seem to be counted. My guess is this the map is based on a combination of walking time and average wait time for a service plus the travel time to a set point in the city centre.
The next map shows a great representation of how people will access the city centre by mode in the future if current plans are built. As you can see the existing rail network plus the CRL serve the South, East and West through connections with feeder buses. The central Isthmus is served by light rail, many of the coastal communities are served by ferry and the rest of the city by bus.
As mentioned earlier, there was some information on the options for rail to the airport. The three images below show how far you would get from the airport on public transport now, with heavy rail and with light rail. As a basis it seems to assume that the isthmus light rail routes have been completed and like the accessibility maps will likely be based on some average wait time and possibly only using normal PT options so no Skybus.
With Heavy Rail you can definitely get much further
And the light rail version which connect to the isthmus routes via a connection from Onehunga to Dominion Rd on a route alongside SH20.
There are some odd things with these maps, for example as I understand it the idea with the light rail option is only the Dominion Rd route would go to the airport which means a transfer for those using the other lines. Why then can you get further up Manukau Rd on LRT when Heavy Rail is much faster to get to Onehunga.
There is more info in there in the interests of time and space I might leave some aspects to another post.
All up a very interesting presentation.
Auckland’s city to airport bus has new owners bringing with them a new name, a new livery and promising a higher quality service. The Airbus Express service has been bought by SkyBus who operate Melbourne’s airport bus service.
Free on-board Wi-Fi and ground hosts to welcome intrepid travellers to Auckland are just the beginning of big plans by new owners to expand – and smarten – the 24-hour airport bus service.
The former Airbus fleet has already had its name changed to that of Melbourne’s 38-year-old SkyBus, which is taking it under its wing.
It will be repainted from light blue to red as more buses are added between the fast-growing airport precinct and downtown Auckland to widen the span of departures, which already run every 10 minutes during week days.
That follows a change of ownership from Johnston’s Coachlines to a consortium majority-owned by Canada’s Ontario Pension Trust, in a deal worth about $20 million.
Melbourne-based directors Michael Sewards and Adam Begg have hit the ground running in Auckland, adding two buses in their first couple of weeks here and installing free Wi-Fi across what is now a 15-strong shuttle fleet – with seven more due by May.
The service has long been popular, running 24/7 and with great frequency. On weekdays they run every 10 minutes between 7:30am and 8:10pm and on weekends they run every 15 minutes during the day. In the middle of the route the frequency splits in two with services alternating between Dominion Rd and Mt Eden Rd. The addition of more buses suggests frequency will improve even further making the service even more useful.
One aspect that is interesting is the move to a red livery like is used on their buses in Melbourne. Queen St already has the red City Link buses so users will have to pay more attention if catching either one. Once they change I wonder how long it will be till someone accidentally gets on a red SkyBus to a short distance up Queen St only to be charged $16 (the one way fare).
The old livery with the new name. Photo by Luke C
One of the reasons the cost for SkyBus is $16 is that the service is and has always been fully commercial meaning it isn’t subsided by Auckland Transport, siting to the side of the normal public transport system. As such the company can charge whatever they like. As such there is also no discount for using HOP and there is no indication that would change with the new operators and it seems they will continue to retain a separate ticketing system
Telecommunications company Spark is meanwhile developing a sophisticated ticket-buying app which it hopes to roll out in Auckland before Christmas and then back-load to Melbourne.
Mr Sewards said during a tag-team visit by the pair to Auckland this week that technological solutions encountered here had been “incredible.”
He is similarly impressed by Auckland Transport’s $100 million integrated Hop ticketing system, into which his fleet was plugged by its former owners, although SkyBus will remain fully commercial with none of the subsidies received by most other city bus operators.
The owners also talk about improving journey times. I imagine the biggest improvements would likely come from having more bus lanes and with better operating hours however the new owners also single out Waterview as helping. Unless they’re planning on running buses all the way to the city via the motorway then I can’t see how that will make a lot of difference.
Mr Sewards acknowledged room for improvement in journey times, now varying from about 45 minutes to an hour for the 12km trip between downtown Auckland and the airport.
That compares with about 20 minutes over the 23km between Melbourne’s CBD and its airport.
But he said Melbourne’s route was far more direct, along a single motorway, and is looking forward to faster bus trips in Auckland once the Waterview tunnels open in early 2017.
Lastly it’s an interesting time for the change in ownership as there are a number of interesting developments on the horizon.
From a PT perspective the competition to SkyBus is a combination of a train and what is currently the 380 bus (will be called the 30 in the new network). Next year Auckland Transport will roll out integrated fares which will make transferring between bus and train services cheaper and easier for most journeys. From the city it would be only three zones for which AT have indicated the cost would be $4.80-$5.00. The trade-off though is likely a longer journey time. Trains between Britomart and Papatoetoe every 5 minutes during the day and from there the 30 bus runs fairly direct to the airport however it only runs half hourly during the day and based on the current timetable even with an almost perfect connection it would take around an hour.
Longer term there is also the prospect of rail the airport. If Auckland Transport build it as an extension of the existing rail system like they should (either between Onehunga or from Otahuhu like suggested here) then travel times could be slashed quite substantially. If instead they go for the option of extending one of the proposed light rail routes travel times aren’t likely to be significantly different to what exists today.
Either rail implementation would have significant impacts on the SkyBus service who I can’t see just lying down and letting it happen. Given SkyBus is already successful and not subsidised they are able to put forward a strong case not to build rail – especially in the current political climate. Yet the service is only really successful on a commercial basis which may not be the best outcome for the city/country due to the higher cost meaning many will still prefer to drive. Based on the current airport arrivals and departures of around 15.5 million people annually the reported SkyBus figures of around 650,000 trips represents just over 4% of travellers. I can’t help but wonder just how much higher patronage would be if you combined both the much faster journeys of heavy rail with the proposed HOP pricing and that’s before you add in making PT more viable for many airport workers.