Most weekends we dig into the archive. Because AWHC is back in the news, we have brought out a post first published almost exactly a decade ago in December 2012.

In the fallout from the release of the City Centre Future Access Study last Thursday and the government’s rather bizarre response to it, for some reason there seems to have been renewed discussion about the Additional Waitemata Harbour Crossing (AWHC) project. It’s a bit odd to think that if Central Government has concerns about contributing to a $2.4 billion project they’d end up looking more kindly on a $5 billion project instead, but I guess as it’s a road rather than a railway line you really never know.

We’ve discussed the AWHC project on this blog many times before, most particularly recently pointing out some incredibly dodgy traffic statistics used by NZTA to help justify the project. In this post I’m not really going to focus on the cost of the project, or the heroic traffic growth assumptions or even why a rail crossing is a much more sensible option. What I’m going to simply look at is the likely traffic effects of the additional crossing – where it does and does not add capacity to the system and what the impacts of that are likely to be. There’s a wealth of information on the project website, which I will draw on to inform this. For a start, let’s just get a rough idea about what the AWHC project is – something that’s reasonably well illustrated in the diagram below:awhc-connectionsIt’s a little complicated with all the different colours, but let’s just think about what happens for southbound traffic:

  • Traffic heading to Shelly Beach Road, Fanshawe Street and Cook Street uses the existing Harbour Bridge
  • Traffic heading to SH16 west and SH16 port exits uses the new tunnel
  • Traffic continuing south on SH1 uses the new tunnel

The same is obviously also true in reverse. Oh an by the way I wouldn’t get too excited about the rail tunnel shown above – the fact that a shuttle line from Gaunt Street to Akoranga is shown, with no connections to the existing or proposed rail network at the city end, just illustrates that it’s only in there as a token gesture.

At the moment in the morning peak there are five lanes southbound coming over the harbour bridge. The Shelly Beach Road offramp peels off but the five lanes remain through St Mary’s Bay. Then one lane drops off at Fanshawe Street and four lanes continue southbound over the Victoria Park viaduct: two of those feeding into Cook Street and the SH16 exits and the other two linking with the Southern Motorway for trips heading further south. Ignoring the city exits (Shelly Beach, Fanshawe and Cook Street) for a minute, it’s clear that there are four lanes that link the Harbour Bridge through to SH16 (for east and west travel) and SH1 for travel further south. Here’s a diagram showing the future layout of the motorway network with the AWHC built:lane-diagram
It’s a bit confusing at first, but once you ignore the local roads it starts to make a little more sense. We can see that southbound in the morning peak there would be three lanes in the new tunnel and four lanes (one of which is a bus lane by the look of it) coming over the harbour bridge. The new tunnel effectively removes ‘through traffic’ from the Harbour Bridge, but doesn’t actually add any capacity over what already exists for that through traffic.

  • There’s still only two lanes which continue right through for southbound traffic.
  • There are only three lanes (compared to the current four) for traffic heading to either SH1 southbound or the SH16 exits.

What the new road does do, of course, is free up huge amounts of new roadspace for vehicles travelling from the North Shore to the CBD. There are now four southbound lanes over the harbour bridge worth of capacity – all of which can only link to Shelly Beach Road, Fanshawe Street or Cook Street. That’s potentially an absolute flood of additional vehicles that could be funneled into central Auckland because they no longer need to ‘compete’ with the through traffic for roadspace over the Harbour Bridge.

This impact is well documented in the project’s Local Roads report:

The main challenge for this assessment relates to the provision of additional capacity across the harbour and the potential flow on effects this may have on the local road network around central Auckland and feeder roads on the North Shore, particularly in the weekday morning peak. In particular it is noted that the new harbour crossing will allow more traffic to enter the CBD. This conflicts with various CBD strategies that encourage the provision of public transport for trips to/from the CBD and not to provide additional capacity for cars.

It fundamentally conflicts with the concept of a liveable city centre.

It is anticipated that space on the existing Harbour Bridge will be allocated to public transport, walking and cycling, if an Additional Waitemata Harbour Crossing is provided. The precise lane configuration on the existing Harbour Bridge will only be determined over time and this will significantly affect the predicted traffic effects of the additional crossing. The scenario agreed for this study (for both bridge and tunnel options) includes the following lane allocation on the existing bridge:

  • One lane for walking and cycling;
  • A bus lane in each direction, but with general traffic heading to the Shelly Beach off ramp sharing the southbound bus lane; and
  • Five general traffic lanes in total, assumed to operate with three southbound and two northbound lanes in the weekday morning peak, with the reverse in the evening peak.

This scenario would provide three southbound lanes for general in the weekday morning peak plus additional capacity, equivalent to around half a lane, for general traffic heading to the Shelly Beach off ramp. This scenario also provides the opportunity for a significant increase in the rate of flow from Esmonde Road (and Akoranga Drive) onto the Northern Motorway, thereby increasing the rate of flow able to cross the Harbour and reaching the Auckland CBD.

It’s hard to know whether to laugh or cry about the fact that even after spending $5 billion NZTA still can’t bring itself to providing a proper dedicated southbound bus lane. The important thing to note from the above paragraphs though is at the very end: the real impact of the project is a massive increase in flows from the North Shore into the CBD. As no additional capacity is provided south of the CBD the are few gains there aside from being able to hit the gridlock through spaghetti junction a bit quicker because vehicles travelling through the tunnel no longer need to compete for roadspace with those heading for the CBD.

It seems as though the report writers began to realise this fundamental flaw with the project and therefore ended up recommending retaining some measures to limit the flow of vehicles onto the motorway from the North Shore:

A range of options could be used to limit the rate of flow able to cross the Harbour, including changes in the lane allocation. However, for the purposes of this assessment it has been agreed that the effects of the additional crossing will be assumed to be restricted by some means and that this should be reflected by modelling ramp signals on the important Esmonde Road southbound on ramp. Capacity constraints are already predicted to exist on the approaches to or on the other on ramps during the morning peak, and providing ramp signals at Esmonde Road will therefore further constrain the rate of flow able to pass across the harbour and into the Auckland CBD.

So we’ll spend $5 billion on adding a huge amount of capacity across the Waitemata Harbour but we’ll still need to use things like ramp signals to limit the flow of vehicles onto the motorway – doesn’t that kind of defeat the purpose of the whole project?

The impact of the project on some city streets is pretty massive in terms of additional vehicles – especially Fanshawe Street and Cook Street (Curran Street and Shelly Beach Road, two residential streets, get slammed as well):local-road-volumesTo cut what is becoming a pretty long story short, it really does seem as though the AWHC project involves spending $5 billion to make it easier to drive your car into the city centre – something we actually don’t want you to do. In other words, it is building the most expensive transport project ever to create more congested inner city streets and a less liveable city centre. It’s a huge amount of money on something that will make Auckland a far far worse city.

For that reason, it is quite simply the stupidest transport project ever.

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  1. “What the new road does do, of course, is free up huge amounts of new roadspace for vehicles travelling from the North Shore to the CBD. There are now four southbound lanes over the harbour bridge worth of capacity – all of which can only link to Shelly Beach Road, Fanshawe Street or Cook Street. That’s potentially an absolute flood of additional vehicles that could be funneled into central Auckland because they no longer need to ‘compete’ with the through traffic for roadspace over the Harbour Bridge.’

    SOLUTION: Impose a $10 road toll each way for cars that use the old harbour bridge to access Fanshawe Street and Cook Street

  2. Am wondering ,if this is being paraded to draw attention away from cost blow out on CRL. There are no traffic figures that make any sense in increasing vehicle capacity across the Harbour,just commuters without a free and easy option of getting to work. That bird has long flown from the nest,the new realities ,are WFH,work where you live,use public transport,walk or bike.
    As highlighted in the article,this creates more problems,than it solves,but “one more lane will fix it ” always strikes a chord.
    The likelihood of this every gaining traction,is dampened down by the eye watering cost,the perverse outcomes ,and the fact that no politician,local or national,will ever be able to claim,”l built that”. At best ,nationally,3 terms,nine years is a govt use by date,locally shorter than that. When inevitably ,Auckland Light Rail falls apart,any additional Harbour crossing is but a “pipe” dream.

  3. I’m not sure if have less faith in the transport engineers in this country to make sensible decisions or the keyboard engineers on this blog site.

    1. Transport engineers? Rather self serving politicians, informed by a large, partially self serving, aging bureaucracy, guided by yesteryears goals.

  4. So the same number of peak direction vehicle lanes, plus a bus lane and a pedestrian/cycle lane.
    Counter-flow does gain a general traffic lane.
    So overall not really traffic inducing, but does help buses and active modes while not doing a lot more other than providing resiliency (which is a fair point).
    Where the plan falls down though is by using tunnels (especially for the non-city SH1 traffic) is that trucks with Dangerous Goods (very common) can’t use tunnels!
    The sensible thing to do would be to build a new bridge similar to Hong Kong’s Tsing Ma Bridge. This would have 2x general traffic lanes each direction, 1x bus lane each direction with rail underneath. This would also be cheaper.

  5. It is not really 5B on a car bridge. 1B can be associated with the lycra lane and 2b can be allocated to rail. That is a 2B spend on adding resilience to an import infrastructure item – possibly the most import – in NZ.
    This has broad cross party support, certainly both National and Labour are for it. I suspect if you ask Aucklanders, they also will support it.
    What needs to be done is this added to the Covid recovery projects, so that RC consent can be rammed through and the project not held up by misinformed eco snow flakes.

  6. I thought we were supposed to be reducing road transport use not increasing it. I HAVE LIVED IN AUCKLAND FOR 50 PLUS YEARS and have only been to Auckland downtown twice. I live in South Auckland and have no need to venture into nobsville. People should work where they live so no need to drive.

    1. What happens if you changed jobs? Does that mean you can only ever work in South Auckland? Or do you need to change houses every time you decide to advance your career?

    2. I think that’s more of a you situation that reflective of everyone, I’ve lived here 24 years and been to downtown hundreds of times, often for work. Which also pokes a hole in the work from home argument, not a possibility for trades, truck drives etc. if you had to do my 1 1/2 hour commute daily you might change your mind

    3. I think that’s more of a you situation that reflective of everyone, I’ve lived here 24 years and been to downtown hundreds of times, often for work. Which also pokes a hole in the work from home argument, not a possibility for trades, truck drives etc. if you had to do my 1 1/2 hour commute daily you might change your mind!

  7. I live in Birkenhead and traffic from there is already heavily incentivised to use PT to get to the CBD.

    The problem is, PT is useless, utterly and completely useless to get anywhere else.

    In my case getting to/from Rosebank Road, which should be simple as it is well connected to an empty motorway from the CBD, and a busy manufacturing centre.
    The solutions are obvious if the planners open their minds and stop focussing soley on the CBD.

    Continue with the poor PT strategies and Bus routings and it is useless.

  8. I wish they would look at a crossing in a different place far from the current bridge. We are just drawing more traffic into the cbd/crl/ spaghetti junction and creating issues.
    I liked a light rail across from the city through ponsonby /Grey Lynn and then crossing on a light rail/ cycling/ walking/ maybe bus bridge between pt chev and chatswood somewhere and then carrying on through western North shore to another light rail/cycling/ walking bridge between beach haven and hobsonville.

    1. How about we expand the capacity of the upper harbour crossing, a spur passenger railway line could utilise the existing Northern line and service the North Shore .. or add buslanes and utilise SH 16/Western Springs to the city.. a tunnel using existing feeder routes is not going to solve the congestion problem..

  9. If this was a heart bypass proposal – it probably wouldn’t bypass the clear section of the artery and feed into the blocked part?

  10. Auckland is a backwater, barely a city. Once you privileged lefties realize that, the better.
    The harbour is a creek, it needs to be crossed. People have a choice; cross it in a covid infested box, cross it by sweating like a rapist, or cross it in the aircon comfort of a BMW/Merc/Audi or whatever. Any sane person is going to take their car.
    I guess your parents over indulged you, but the harsh reality for you to understand is majority rule. Look no further than the changing political landscape at local and national elections and you can see what the majority want.
    Just get over yourselves, or F O to Denmark (if you can get a visa), The NZ you want is out of step with the NZ the majority of Kiwis want.

    1. Man, the National/ACT takes seems to be wildly pro-wasting a huge amount of time and money on something we could achieve far more efficiently without tunnels as well as pro-crapping their pants over someone having a different opinion to them.

      Remind me again, which one of us is meant to be the snowflakes here?

    2. If more people make their lives within “Human powered distance” (battery assist is okay by me) of where they live NZ will become wealthier.
      Euro trash cars DO NOT make NZ Wealthy!
      Walking over the harbour repeatedly is a dumb idea.
      For a start the bridge doesn’t like being walked on, it is a cold windy place most of time…
      A Team NZ engineered cycle lane would achieve a similar capacity improvement for a fraction of the cost.

  11. Spend the 5 billion on a mega fleet of electric buses that run frequently on North/South, East/West and ring routes. 3 billion to cover the cost of buses, 2 billion invested to pay drivers and running costs. Should be very low cost/free to ride. Problem solved.

  12. What is needed is to create better use of the city’s motorway network by removing all the congestion causing on ramp signals and replacing with toll gantries on all motorway on ramps from Warkworth to Bombay, which would replace the present Auckland fuel levy. The toll gantries would only be on the on ramps and not at the beginning of the motorways, so as not to charge people traveling right through Auckland.

    Doing this would: 1) reduce unnecessary travel on the motorways, 2) help to incentivise people within Auckland to use alternative options such as public transport, and 3) keep the motorways freer for those that really need to use them and making it worth paying to use.

    The tolls collected on the motorway system would then help fund the following essential transport infrastructure projects which Auckland needs:

    1. Replace the current Auckland Harbour Bridge with a new bridge, to a design similar to that proposed with the ANZAC Centenary Bridge a few years ago, which would incorporate road traffic lanes on the top, with light rail, pedestrian and cycle paths underneath, running in a more direct route from Victoria Park in the CBD through to Northcote Point:

    2. Convert the Northern Busway into a regular standard street level light rail line running from Silverdale via the new harbour bridge into the city along Fanshawe Street, into two routes running 1) via Queen Street, K Road, Great North Road and the SH16 Northwestern Motorway to Westgate, and 2) via Customs Street, Anzac Avenue, Symonds Street, Dominion Road to Stoddard Road in Mt Roskill.

    3. Create a proper motorway into East Auckland with converting the South Eastern Highway (from the intersection of O’Rorke Road in Penrose), through Ti Rakau Drive and Te Irirangi Drive into a proper full 100km/hr motorway, with grade separated interchanges along its length, including with the SH1 Southern Motorway at either end at Mt Wellington and Manukau.

    The road corridor is wide enough to do this, as well as in conjunction:

    4. A new street level light rail line to be built along the route of the new eastern motorway from Panmure station, along the route of the current Eastern Busway along Lagoon Drive, Pakuranga Road, Ti Rakau Drive, Te Irirangi Drive, Great South Road, Ronwood Avenue, Davies Avenue to Manukau station.

    5. Build a heavy rail line between Onehunga and Puhinui / Manukau via Auckland Airport, with double tracking the existing Onehunga Branch line and extending it across the Manukau Harbour to Auckland Airport, through to the main trunk line at Puhinui, running alongside SH20 South Western Motorway, SH20A and Puhinui Road.

    Doing this will then enable the current Onehunga line and Eastern line via Panmure to be linked together in a large teardrop shape loop via the City Rail Link tunnel and Manukau station, providing a rapid transit loop which covers most of urban Auckland.

    Also in conjunction with this, the current Southern line and Western line would be linked together into one route which runs across Auckland from Pukekohe to Swanson / Helensville, which needs to be achieved with:

    6. Extending the double tracking and electrification on the North Auckland line (Western line) from Swanson to Helensville.

    By doing this, two simple ‘one seat journeys’ would be created with the existing heavy rail network with a central loop covering much of the city, and a cross town route running from one side of Auckland to the other.

    Having a rail line running via Auckland Airport would also enable a much-needed proper decent long distance inter-regional rail terminal to be built for Auckland at the airport, thus providing better links into Auckland and to the Auckland International Airport from neighbouring regions.

    Doing all the above would significantly help reduce Auckland’s congestion and improve travel times across the city, by reducing unnecessary travel on the city’s motorway network, while at the same time providing a proper fast motorway route through East Auckland, and creating a sensible heavy rail and light rail rapid transit network along routes which will be of the most benefit and use to a far greater number of people across Auckland.

    1. Tolls cannot only be on the motorway network. Otherwise it will displace current motorway trips onto local surface streets, create a heap of congestion, and put more traffic onto infrastructure that is more dangerous, and heavily used to pedestrians / bikes / buses.

      Congestion charging needs to be complete rings, or there needs to be massively more bus priority on surface streets. Or it will make the motorways fast for a select few, and demolish every other trip anyone makes in the city.

  13. Well for what its worth my idea was that the new link had rail to CBD and the car lanes went under the city and only emerged at tip top corner.
    Why do this well it means you bypass 90% of the bottle neck areas. So if you want to get tobthe CBD you take train or your car over the bridge.
    This then allows a good gast trip to the real south.

  14. So the thing to bear in mind here is that providing extra roads into the CBD will not entice any more cars there during the week, there isn’t enough parking and office use is in decline. During weekends/public events it will be handy, but you either work there or you don’t, so the old bridge will be half empty with a nice light flow of traffic and occasionally a cyclist or pedestrian who feels like he needs some serious exercise on a windy rainy day. The only useful purpose for the extra bridge capacity would be a light rail link to Britomart or Mt Eden. So a link inside the new city rail tunnel will needed. While I agree it doesn’t provide extra capacity for traffic heading south or west, at least they won’t be stuck on the bridge

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