Challenging the road planners

by Michael C Barnett
The Regional Council, the City Council and the Transport Agency are currently engaged in their “Let’s Get Wellington Moving” initiative on how to resolve traffic and transport issues in the city.

Following lengthy public engagement and surveys during 2016, key findings indicated that people valued the compactness of the city and ease of getting around; they want public transport improvements, fewer roads and cars, a more pedestrian-friendly city, and protection for the natural environment. These findings represent an admirable expression of what kind of city environment people would like to see. But achieving them will take a paradigm shift away from expanding the road corridor between the Terrace tunnel and Cobham Drive, which forms a major part of the current Land Transport Plan.

There is much evidence in New Zealand and abroad to indicate that constructing more motorways and bridges through an urban area does not lead to significant travel time savings or easing congestion (which is the common assumption of road and traffic engineers.) Conversely, there is much evidence that total or partial road closures can lead to a significant reduction in the amount of traffic in the vicinity, thereby achieving the easing of congestion that everybody wants.

American writer and political activist Jane Jacobs spent a lifetime studying and writing about economic development and the decay of city environments. Jacobs did not have a high opinion of traffic engineers and traffic management as it has been practiced over the past 60 years. She castigated them for their failure to ask and address the right questions, and their failure to investigate after desired outcomes are not achieved.

She claimed that “in the pursuit of maximising traffic movement, traffic engineers have abandoned and betrayed science as it is understood” and she described two examples where communities challenged the professionals and their proposals for traffic improvements.

During the 1950s she led community action to save New York’s Washington Square, a community park in Greenwich Village, from bisection by a limited access expressway, and to close a 2-lane carriageway through the park to all but emergency vehicles.

During the debate leading up to abandonment of the expressway and closure of the road, “the traffic commissioner told us traffic is like water: if it is dammed up or diverted from its course in one place, it will find other outlets where it meets less resistance. To close off the carriage road without providing a new road would, he predicted, inundate all the narrow streets in the park’s vicinity with thwarted traffic and belching fumes, threatening the safety of children to the point that they couldn’t even reach the park.” Following a test closure of the road, these predictions did not come to fruition. Nowhere did the traffic increase. Traffic counts were slightly down in the park’s vicinity. “Where did the traffic go? This question was never asked.”

Jacobs also describes a dispute 30 years later with authorities in her Toronto neighbourhood, where a similar situation arose and was fought by the community. The same water analogy was presented by the traffic engineers and was subsequently debunked. Jacobs writes:

“Here they are, another generation of nice, mis-educated young men, about to waste their careers on a fake science that cares nothing about evidence, that doesn’t ask a fruitful question in the first place and when the unexpected evidence turns up anyhow, doesn’t pursue it.”

Once again the traffic flow projections had been discredited by real world experience and once again the reasons why it was wrong were not investigated.

Jacobs also described her observations when travelling by taxi to a downtown destination in Toronto. On a trip from the airport to a downtown micro destination, one part of the trip was along an elevated limited access highway, with on and off ramps feeding to and from the city’s grid of one-way streets.

“On the expressway stretch the meter is ticking over, the trip seems economical and I am getting good distance for my money. Then I hit a choke point at the exit ramp and from then on everything changes. Considering what it is costing me, I am getting very little distance. I am not complaining about this. As research it is economical. What worries me rather, is the expensive burden on the city and the planet of air pollution and urban road congestion that the expensive part of my trip is registering.

“The driver must weave circuitously around the block, then around another block and so on to reach the correct side of the street on which to deposit me. All the way to my micro-destination, from the moment we enter the street grid, we are surrounded by delivery vans, other taxis, and private cars whose drivers also are attempting to reach their micro-destinations. ….. Our joint circuitous congestion hampers all others attempting to make use of the streets: public transit vehicles, pedestrians and bicycle couriers.”

She identifies what she considers to be two serious flaws.

Firstly, instead of addressing the question ‘how can we help this great diversity of users reach their great diversity of micro-destinations most directly?’, the designers seem to be asking themselves – ‘How can people reach a macro-destination downtown most speedily?’

The second flaw is that the one-way street system leads the driver on a Barnes dance to reach a micro-destination. The no left turns, no standing signs and other rules are designed to keep vehicles out of one another’s way and carry out the theme of a speedy trip. She suggests that perhaps one-way street systems are not such a good idea.

A study by a research team at the University of London and reported in The New Scientist in 1998 tends to suggest that Jacobs is right. This study identified sixty cases worldwide in which roads had been closed or their carrying capacity reduced and its principal findings were:

· Planning models assume closing a road will cause traffic using it to move elsewhere

· Computer models used by urban transportation planners yield incorrect answers

· When a road is closed, an average of 20% of its traffic seemed to vanish and in some cases as much as 60%.

There are many examples where enlightened planning authorities have moved to close highways and channel investment into public transport, walking and cycling to and improve the urban environment.

Wellingtonians are asking for public transport improvements, fewer roads and cars, a more pedestrian friendly city, and a desire to protect the natural environment. This is achievable, but expanding the road corridor to Cobham Drive is not the answer.

Maybe closing the Vivian Street off ramp and directing through traffic two way along the existing corridor to the Basin Reserve and beyond would be worth trialling.

Whatever the outcome, one lives in hope that the Let’s Get Wellington Moving team will take note of the fallacies identified by Jacobs and the positive experience in cities that have seen the wisdom of putting people first and designing transport systems around the desired urban form.

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



  1. Luke, 31. January 2017, 9:49

    I was standing at the lights recently waiting for a procession of single occupant vehicles before I could cross Vivian Street. I’m unsure why being in a vehicle gives one priority over somebody on foot. Cities are for people not cars. Same applies to the mini motorway seperating Wellington from its waterfront. Your trial suggestion has merit. Failing that, sh1 should go be trenched under Tory St and other pedestrian thoroughfare.

  2. Ross Clark, 31. January 2017, 23:42

    People will not take their cars into a city centre if they have no-where to park them. While reducing non-commuter parking may not be feasible, tackling *commuter* parking is the challenge everyone is avoiding.

    The main focus of the road network should be to take people *around* the central city, instead of *into* the central city. This is how Amsterdam works; a superb public transport network for the inner city and a ring road network as well – especially if it is configured in such a way as to prevent short-distance journeys from using it (the main flaw of London’s M25).

  3. Traveller, 1. February 2017, 9:23

    That’s a brilliant idea to rescue Vivian Street by closing the offramp from the motorway. But what route is proposed for all the southbound traffic? (There’s not much room on Karo Drive.)

  4. Guy M, 1. February 2017, 10:16

    Well, actually Traveller, the Arras Tunnel is 4 lanes wide at one end, so you could, technically, probably get 2-way traffic through there if you tried…

  5. Traveller, 1. February 2017, 10:55

    But not all of Karo Drive is four lanes. At its Cuba Street crossing, a heritage building might have to be sacrificed. And at the Willis Street intersection, new blocks of flats have just been completed on either side of the road – a sad example of planners’ inability to consider the future. Of course, tunnelling would solve most of these problems. Specially under Cuba Street, where pedestrians have an interminable wait to cross the highway.

  6. Brent Efford, 1. February 2017, 14:03

    Brilliantly written, Michael – it is about time that the core assumptions behind Wellington traffic engineering were challenged. Unfortunately, conservative local politicians and planners have bought into those assumptions to the extent that we now have one of the most highly motorised cities in the world (yes, really – third highest CBD parking provision and HIGHEST motorway lane length per citizen, according to Prof Peter Newman) AND one of the most incomplete rail transit systems – it doesn’t even penetrate the CBD, a dysfunction few other rail PT systems suffer.
    My experience of perforce having to drive the route at afternoon peak periods on occasions is that the worst congestion going north occurs between Arras Tunnel and the start of the motorway – precisely the bit that the Inner City Bypass (Karo Drive) was touted as fixing (and which the alternative of a continuous parallel Wellington City Rail Link spine would alleviate). Sure, the Mt Vic Tunnel approaches crawl at such times but they keep moving, not so the 4+ lanes to the north.
    So much for “four lanes to the planes” as some sort of solution – and just wait for those new Transmission Gully motorists added to the traffic stream in a few years!
    My fear is that LGWM is inherently fixated on alternative traffic engineering approaches, not sustainability and quality of life. We’ll see!

  7. Russell Tregonning, 1. February 2017, 21:32

    Very good research, Michael. Jane Jacobs has made a major contribution in debunking many of the perceived ‘truths’ ( ? ‘alternative facts’) believed by traffic planners.
    At a lecture to U3A Wellington on 13 June 2014, Mike Seabourne, NZTA transport planner & manager Central Region, said (paraphrased) “Traffic is like water and needs wide channels”. So we travellers haven’t got a brain? No Mike– the evidence says we choose another route/mode/time to travel when congestion occurs–we don’t just passively move in our mindless aqueous way (despite the fact that the brain is mainly composed of water).
    Also, from Mike–“NZTA has to act like good corporate citizens towards its customers”. So we taxpayers who fund billions to NZTA at the expense of rail and active transport infrastructure) are just ‘customers’.
    We need an overhaul to our land transport arrangements. NZTA must be a true ‘transport’ organisation–not just a road/car/ truck promoter. We ‘customers’ need to ask for better.

  8. Kerry Wood, 2. February 2017, 10:15

    The odd thing is that we have been throwing away money for so long. It has been 40 years since we learned that good passenger rail manages congestion by controlling travel times. Now we know that buses and trams give the same benefits if they have priority, such as Auckland’s Northern Busway. Public transport may attract two thirds of commuters when travel times are equal.

    A 2007 technical paper of mine showed that parking provision in central Auckland (spaces per 1000 jobs) was higher than either Los Angeles or Houston. Christchurch was higher still and Wellington highest of all, despite a relatively low proportion of commuters by car.

    The economic benefit of more roads is wiped out by ‘triple convergence’ of existing traffic from three sources:
    Other routes: now I can take the direct route.
    Other modes: now I can save time in the car.
    Other times of day: I can spend another ten minutes in bed.

    Another effect is happening right now. A building boom on the Kapiti Coast, with rising land values, as Transmission Gully is built. London went though that experience when the M4 opened in the 1960s: it was congested on Monday morning, and still is.

    We need a major rethink of transport, nationally and locally: it will benefit everybody.

  9. Richard Keller, 2. February 2017, 15:52

    Nice two articles, Michael. So how do you explain the insistence of the traffic planners to ignore the actual results? Surely the answer lies in their commitment to a larger idea? To an ideology? I eagerly await your explanation (before I offer mine.) Thanks.

  10. Henry Filth, 3. February 2017, 14:38

    If public transport took people from where they are, to where they want to go, when they want to go there, it might be a lot more popular. So how do we get to that happy state? Is it really by throwing all the money into high capacity, high volume, limited destination systems? Systems that don’t take people where they wsnt to go, require frequent changes and waits, all in foul wet Wellington weather.

  11. Kerry Wood, 3. February 2017, 20:33

    This is off-topic, but very briefly:
    — Most people live near or sometimes on two bus routes.
    — The central city bus route is heavily overloaded. I have seen queues of 13 buses, and I believe they are sometimes longer.
    — Making changes slows the trip, of course, but that can be offset by making public transport faster, with better timekeeping and timetables designed for quick transfers.
    — An integrated system like this, with no delays, has far fewer bus route kilometres and needs fewer buses. Buses on the remaining routes can run more frequently, which allows faster transfers.
    See also NZTA research paper 396.

  12. Michael Barnett, 4. February 2017, 17:23

    Traveller. The answer to your query re Karo Drive, two lanes – one in each direction – is all that is needed. As Jacobs and the University of London research studies have pointed out, many cities around the world have closed roads and reallocated existing road space this has resulted in a significant reduction in traffic volumes with no adverse effect.

    In their modelling traffic engineers tend to make make wrong assumptions about where traffic goes – wrong assumptions in wrong answers out. As the researchers have discovered, traffic reduction can be partly explained by recognising that people react to change in road conditions in much more complex ways than has traditionally been assumed in traffic models.

    I believe there is a strong case for trailing what I suggest. If successful and I believe it would be, it opens up an entire area of the central city to redevelopment along the lines of the expressed desires of the Lets Get Wellington Moving surveys respondents.

  13. Michael Barnett, 4. February 2017, 17:35

    Like Jane Jacobs says, they don’t ask the right questions, and when results are not what they expect they do not follow up and ask why? My belief is that here in New Zealand the roading culture of NZTA influences all that they do and they do not look beyond more motorways as the solution to traffic and transport problems. Culture change is not easily achieved and perhaps we need a new government funding agency dedicated to urban design and transport planning for our major metropolitan areas.


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