Wellington Scoop

Decongesting traffic – without more roads


by Michael C Barnett
In a recent article, I challenged Wellington’s road and transport planners to expand their thinking and to ease congestion in the city by making a paradigm shift away from more road construction. I suggested that proposals to expand the road corridor between the Terrace Tunnel and Cobham Drive should be abandoned, the Vivian Street off ramp should be closed, and southbound through traffic should be redirected along Karo Drive to the Basin Reserve. How will this work and what would be the benefits?

Currently, driving west from the Arras Tunnel along Arthur Street and Karo Drive to the Terrace Tunnel there are three traffic lanes for through traffic, except for the short stretch of road between Abel Smith and Vivian Streets where it narrows to two lanes. With a little re-engineering, this section could accommodate a third lane, allowing for the free flow of traffic in two directions; one lane west to east and two lanes east to west. With the exception of the closed ramp at Vivian Street, all other options for entry and exit would remain unchanged.

What would be the benefits of such a change? At present, through traffic traveling west to east passes through seven sets of traffic lights along Vivian Street and Kent Terrace.

The same traffic re-routed along Karo Drive and Arthur Street would travel a shorter distance and encounter only four sets of traffic lights, resulting in significantly reduced travel times. I would guess that the time saving would be greater than the 90 seconds promised by NZTA, when it was promoting the Basin flyover.

And what about the Basin Reserve? Much has been made of the difficulties at this so called choke point. But there’s nothing that some commonsense and low cost changes to the current set up could not fix.

Several suggestions were tabled at the 2014 Board of Inquiry. Mine included the removal of many of the physical obstacles to allow for freer flow of moving traffic around the Basin.

Along Dufferin Street on the east side of the Basin, more than half the road width is taken up with parking space for buses and cars, leaving only two lanes for moving vehicles. I consider this an embarrassing waste of road space to provide for parked vehicles, which use it for less than two hours a day when school is in. There are other constrictions limiting the free flow of traffic around the Basin Reserve. Why not remove these obstacles and associated traffic lights and let the Basin operate as a giant free flowing roundabout? Not only would this reduce congestion would also allow for a dedicated bus lane around the outer perimeter.

These are things that should be implemented now, rather than waiting three or four years to reach a compromise that may not even work.

Consider too the potential impact of freeing up Vivian Street and Kent Terrace from excess traffic flow. A substantial part of the central business district could be opened up too much needed redevelopment, in a manner compatible with stated objectives. Currently, the area bounded by Courtenay Place, Cuba Street, Karo Drive and Cambridge Terrace is a wasteland of under utilised commercial and vacant land. With foresight and careful planning this area could be developed into a wonderland of residential, retail and commercial property with a scattering of open space to meet community needs.

Wellingtonians have asked for public transport improvements, fewer roads and cars, a more pedestrian-friendly city and protection of the natural environment. These are desirable goals, but to achieve them will take a paradigm shift in thinking. Proposals for a second Mount Victoria Tunnel and the widening of Ruahine Street and Wellington Road are not compatible with these objectives.

Further, I reiterate there is a common misconception that more motorways will ease congestion and reduce travel times. This in spite of worldwide evidence to the contrary. During the past forty years, many cities around the world have closed roads and reallocated existing road space and in the process significantly reduced traffic volumes with no adverse effect. Our planners and decision-makers need to take note of these traffic engineering fallacies and the positive experience of these cities that have wisely put people first and designed their transport systems around the desired urban form.

Over one billion dollars is currently budgeted to expand the road space along the east/west corridor from the Terrace Tunnel to Cobham Drive. This money would be better spent on public transport, walking and cycling. All it requires is a change of mindset and a focus on reducing the volume of traffic entering and/or passing through the city at peak hours. Reallocating the existing road space as I have suggested forms one part of the equation toward achieving this.

Michael C Barnett is a retired Wellington civil engineer with experience in roads, transport and urban development.


  1. TrevorH, 9. February 2017, 9:14

    Yes, some of the impediments around the Basin Reserve could readily be removed to improve the flow of traffic. But the need for a second tunnel through Mt Victoria remains and is pressing. Economic activity around the airport and in the Eastern suburbs has expanded enormously in recent years. So has the resident population through infill housing and other property development; Shelly Bay now looks set to be the scene of further housing expansion. The route is also part of State Highway One and therefore nationally important. Failure to act imposes a serious constraint on Wellington’s future. More cycle routes won’t fix this.

  2. Russell Tregonning, 9. February 2017, 11:51

    A second tunnel through Mt Victoria, like the proposed new lanes added to Ruahine Street (where no-one lives) will just increase car traffic through our city and despoil our valuable town belt. Not only that, but congestion will soon return.
    There is a better way, as Michael Barnett suggests i.e. reduce car traffic entering the city. This will make our city less congested, cleaner and more liveable. Better public transport like all-electric light rail via the hospital to the airport with connector buses to this central spine will be a much better way to spend $1billion+ . This enhanced public transport together with safer cycle& walking infrastructure is the 21st century way of combating congestion, reduce climate and other pollution while giving major health benefits.

  3. Kerry Wood, 9. February 2017, 20:24

    The problem is that cars need too much road space and junction time. Three cars, typically carrying up to four people at peak hours, need as much space as one bus, typically carrying 40–60 people at peak hours. Worse, drivers often expect to use road space for parking. More emphasise on providing for cars makes walking and cycling dangerous and unpleasant, and their response makes congestion worse

    Your assumptions make good sense if urban transport policies in New Zealand are and will remain the best approach. However, there is good evidence that other ways of doing things are cheaper, more sustainable and much more effective.

    — Why does closing a motorway make little or no difference? Questions were being raised as early as the 1930s, in both London and New York, and now New York’s Broadway is down to a single traffic lane at one point. Check out ‘Induced demand’ on Wikipedia.

    — A new factor is climate change. Continuing present transport policies is unsustainable, not in the tree-hugger sense but the economic sense: ‘Things that cannot go on for ever stop.”

    — A special factor in Wellington is the very restricted street space in the central area. The worst point for public transport is between Stewart Dawsons and Frank Kitts Park. Effective solutions are going to need four lanes and either bus rapid transit or light rail. However, BRT stops in Brisbane are 27 metres wide: twice the width of Manners St. Light rail might be cheaper by the time enough space has been found for BRT.

  4. luke, 9. February 2017, 21:40

    it would be foolhardy to spend a large sum of money without at least trialling this idea for a couple of years.

    Light Rail has got to be part of the mix between Newtown and the railway station to reduce the number of buses too

  5. KB, 10. February 2017, 14:36

    Autonomous electric vehicles are going to lead to a boom in car usage , and a massive decrease in fixed route public transport – whether we like it or not. Which means we are going to need more and smarter roads. Pretending this isn’t going to happen soon and preaching 20th century solutions is delusional head-in-the-sand thinking.

  6. Andrew, 10. February 2017, 15:34

    KB, all I can think of after reading your comment is the blimp sized humans in the ‘Wall-E’ movie who are too lazy (or otherwise inclined) to get up and walk.
    More roads? Is that the sum total of 21st century thinking?

  7. Ross Clark, 10. February 2017, 23:26

    As I keep harping on: fix central city parking provision, so much of the car traffic isn’t coming into the CBD in the first place, and the road network can concentrate on taking traffic /around/ the CBD.

  8. Guy M, 11. February 2017, 8:28

    KB – autonomous cars MAY be the answer or they may not. There are more unanswered questions about them than there are answers, as yet. Remember the Segway? That was going to change the world too. It didn’t – it just became a gimmick. My guess? That we will still need good, cheap, fast, convenient, safe, comfortable, and affordable public transport systems in 100 years – and who knows what that will be. But it is unlikely to be cars, autonomous or not.

  9. Kb, 11. February 2017, 8:51

    @Andrew I love that movie! And yes I agree with you. unfortunately history shows us we usually can’t stop people from doing things that in the long run are worse for them (absent regulation). A big advantage of autonomous cars is that they will enable a boost in freedom of movement for a big chunk of the population who do not have their own personal transport (particularly the elderly, but also children/teenagers, the disabled etc) to greatly increase their mobility. However this will increase car usage.

  10. City Lad, 11. February 2017, 22:44

    There’ll never be autonomous vehicles. Humans won’t accept the risks involved.

  11. Wellington Commuter, 12. February 2017, 8:55

    @City Lad likely to join an illustrious club about future predictions:

    “This ‘telephone’ has too many shortcomings to be seriously considered as a means of communication. The device is inherently of no value to us.” — Western Union internal memo, 1876.

    “Radio has no future. Heavier-than-air flying machines are impossible. X-rays will prove to be a hoax.” — William Thomson, Lord Kelvin, British scientist and President of the Royal Society, 1893

    “The actual building of roads devoted to motor cars is not for the near future, in spite of many rumours to that effect.” — Harper’s Weekly, 1902

    “Who the hell wants to hear actors talk?” — H. M. Warner, Warner Brothers, 1927

    “Atomic energy might be as good as our present-day explosives, but it is unlikely to produce anything very much more dangerous.” — Winston Churchill, 1939

    “There is no reason anyone would want a computer in their home.” — Ken Olson, president, chairman and founder of Digital Equipment Corp., 1977.

    “640K ought to be enough for anybody.” — Attributed to Bill Gates, 1981

    “I do not think that there will be a woman prime minister in my lifetime.” — Margaret Thatcher, when Education Minister

  12. Kerry Wood, 12. February 2017, 11:25

    Ross is right: a big part of the problem in Wellington is too many parking spaces. Twenty five years ago parking in central Wellington (measured as places per thousand jobs) was over 1100, comparable with Christchurch and Phoenix and substantially higher than Detroit, Houston, Denver, Perth, Adelaide or Auckland. It was double the figure for Los Angeles and four times the figure for Sydney. (Kerry Wood: ‘The paradox of congestion’ IPENZ Transportation Group Conference, 2007).

    At a guess Wellington still has very high provision for car parking, and too much of it is street parking, wasting valuable space much better used for other purposes, such as hire bikes.

    Autonomous car may help a little. They may be able to increase street capacity by more consistent speeds and shorter gaps between cars, but nowhere near the tenfold benefit from a bus lane.

    KB may be right, that we can’t stop autonomous cars, but so what? Autonomous cars can only use the roads available and fewer lanes will limit their use. If their popularity causes queues, the alternatives will simply be better-used, and everything brought back into balance. Central London is expecting more travel on cycles than in cars within a decade, and New York has shut part of Broadway down to one traffic lane.

    And the congestion caused by reducing capacity? None, except perhaps for a few days until people get used to it.

  13. City Lad, 12. February 2017, 12:28

    Henry Ford and his Model T revolutionised the motor industry. Cars still have four wheels and driven by us humans. Some trains in other countries are autonomous. But they can’t stray from the tracks. Mr Ford would be shaking his head at the thought of having driverless road transport.

  14. Wellington Commuter, 13. February 2017, 9:05

    @City Lad … I seriously doubt that Henry Ford “would be shaking his head at the thought of having driverless road transport” … he was a true visionary industrialist that changed the world and would more likely be part of this movement than being a nay-sayer.

    If you are interested, one article on the breadth of Henry Ford’s vision and how revolutionary it was at the time is: http://www.assemblymag.com/articles/83965-special-section-the-extraordinary-vision-of-henry-ford

  15. Richard Keller, 13. February 2017, 9:06

    Thanks Michael for again calling out the ‘road and transport planners’ (engineers) for their desperate promotion of more roads in a time when it is clear to all that radical reductions of carbon emissions is a top priority. Of course the engineers are counting on the continuing support for their plans from the Kapiti and Hutt suburbs who continue to see Wellington city primarily as an obstacle in getting to the airport.

    Thanks particularly for the detail in suggested changes. For me, it would be useful to see diagrams. Do you have any?

    Perhaps ‘wonderland’ is a bit beyond reasonable expectations, however, so have a think about that.


  16. Rumpole, 14. February 2017, 7:42

    While travelling on the rural road in her autonomous car, my client was reading a newspaper and drinking Champaign. She cannot be held responsible for the collision with the herd of cows. It was entirely the car’s failure to avoid these animals. My client and the farmer will both seek substantial compensation from the car manufacturer.

  17. Glen Smith, 14. February 2017, 8:33

    Michael. Nice articles challenging the pervading misconception that building more roads improves congestion and, conversely, that closing roads necessarily increases congestion. However Wellington’s population is predicted to grow by 46,000 (23%) in the next 30 years and if we want to keep an open mobile city we need to plan for the predicted 20% increase in passenger trips. Before we start halving the capacity on major thoroughfares, and alienating the majority of the population who still rely on cars, we need some more analysis. When roads overseas are closed and congestion doesnt increase where do the cars go? And is the same likely to happen in Wellington?
    The cars disappear by Anthony Downs ‘Triple Devergence’ (the converse of triple convergence mentioned by Kerry Wood). That is each individual commuter will make a behavioural decision that maximises their travel efficiency. If a particular route is congested at a particular time they will choose a different route (spatial divergence), a different travel time (time divergence) or a different travel mode (modal divergence) until the increased congestion on these alternatives counteracts any advantage in changing. An equilibrium is reached. Any infrastructure change will produce behaviour change until a new equilibrium is achieved.
    The Vivian St and Karo Drive/Arthur Street routes are for across town commuters who have to get past Wellington’s narrow ‘waist’ occupied by the CBD. Alternative routes are scarce and already at capacity so spatial divergence isnt an option. Similarly commuters have already largely filled time divergence options (a previous co-worker got up at 5 am to commute from the Hutt) with congestion extending for ever longer periods of the day. What we want is mode divergence onto bus and rail, which, with potential efficiency almost an order of magnitude higher than road, is essential in our compact city.
    Sadly, as Hamlet would say, ‘there’s the rub’. The across town public transport barriers are huge – so huge as to be almost impossible. Commuters have to endure an up to half an hour across town bus penalty along the most busy streets in the city, and rail users an additional 5-10 minute mode transfer penalty at the station. Congestion would have to increase to a 40 minute delay before across town car users are likely to diverge to public transport. Even if they did, the Golden Mile is already 100% over capacity with no ability to absorb growth let alone any divergence from road.
    A second across town public transport corridor is essential. This should be a high quality ‘bypass’ route. The only real option is the Quays, using 2 of the 6 lanes, which would also service the CBD. The mode should be rail to integrate into our existing efficient network, preferably (as Brent Efford advocates) seamlessly. The logical destination the airport.
    Until this essential corridor is established, decreasing capacity on existing across town roads will only increase congestion and alienate the public, rather than achieving the mode shift to public transport that we want.

  18. Luke, 14. February 2017, 11:13

    I agree, funnelling all Public Transport along a heavily congested golden mile while a 6 lane mini motorway exists a block away is ridiculous.

    A quick trip with Public Transport along the quays gets my vote.

  19. Wellington Commuter, 14. February 2017, 14:42

    Glenn & Luke. A PT dedicated route along the Quays is a good idea but it has already been explored in depth. The bottom line is it simply doesn’t work for a large number of current and potential future PT users because the walking access is too far for them (e.g. if you work on The Terrace, it is a long walk to the quays compared to getting to Lambton Quay). This means any dedicated PT on the Quays will likely be under-utilised while Lambton Quay PT services will remain overloaded.

    So from a vehicle point of view you may get “A quick trip with Public Transport along the quays”, but from a PT commuter end-to-end travel point of view it would be considerably slower.

  20. Kerry Wood, 14. February 2017, 21:11

    FIT has been able to come up with two new routes, so I am not sure what happened about ‘explored in depth.’ Yes, there are a few rubs, but the solution has to be “four lanes to the trains.” The Spine Study assumed four lanes for modelling, on part of the route, but then they seemed to fade from sight, a bit like the Cheshire Cat.

    The obvious first option is an upgraded golden mile, but Wellington will need something better before long. The golden mile is already carrying 6000 PT passengers an hour in the morning peak. It is approaching a hard limit, with delay demonstrations daily. Some people don’t want to walk far, and good light rail avoids frequent stops, so the golden mile is probably best reserved for buses.

    Additional capacity is available: all it needs is reprioritisation. Using figures from the Global Street Design Guide (Wellington is in it: Lower Cuba St), a 3 metre lane can carry around 10,000+ people an hour on light rail, 4000-8000 in buses, 8000 on foot, 7000 on bikes, 600-1600 in cars. But none at all in parking lanes.

    One new option for light rail is on the seaward side of the waterfront, clear of turning traffic. It could be non-stop, or with stops at Kumutoto, Frank Kitts Park or both. Overbridges will improve access, possibly with a covered overhead walkway all the way to Lambton Quay.

    Another new option puts light rail on a pedestrianised Lambton Quay, with two lanes for light rail and two for buses. This works as far south as Midland Park—with an interchange—and then light rail can wriggle across to a waterfront stop at Frank Kitts Park. It has very little effect on existing traffic circulation, apart from private motor vehicles on Lambton Quay: see http://intranet.affinity.co.nz/projects/FITWellington/ for details.

    The big advantage of an overcrowded route is that it justifies the step-change Wellington needs. 6000 passengers an hour could be split between say 4000/hr on light rail and 2000/hr on buses, and 4000 pass/hr is usually enough to make light rail viable. Trams could run as often as every five or six minutes on opening day, reducing transfer delays to a reliable three to five minutes or so. Combine that with light rail generally on reserved lanes, and many trips will be faster with a transfer than they are without a transfer today. Better still, transfers make a much wider range of travel options practical on public transport.

  21. KB, 15. February 2017, 16:07

    I don’t get the argument for light rail happening because 4000+ passengers an hour use it along Lambton Quay. This is one tiny section of the transport network where multiple routes converge – except for the short inner city route, those 4000+ passengers are all travelling on seperate routes that go in different directions, none of which are anywhere near 4000+ passengers an hour.

  22. Kerry Wood, 16. February 2017, 10:55

    This is the reality of public transport. It must be designed for peak flows, then manage off-peak demand with reduced services, without cutting services back so much that they become unreliable. A well-managed bus route will often have buses running empty, but they are still useful because they have ‘option value’: users have certainty that the bus will be available if they need it, at the advertised time. It sounds inefficient compared with cars, but is efficient when you look at the overall system, saving energy and reducing congestion.

    If a bus run was cancelled as soon as the patronage went below six passengers or so, what sort of patronage would it attract? More savings come when families decide that they no longer need a second or third car, because the bus is cheap and effective.

    Light rail is just the same, except that it can carry many more passengers without overloading the route.