Flashback Saturday: The linear city and other science fictions

This post by Peter Nunns was first published in March 2016

Last week, urban designer lecturers Dushko Bogunovich and Matthew Bradbury published an article on their vision for transforming Auckland into a “linear city”:

Instead, we suggest a linear, city-region that follows the opportunities and respects the constraints in the landscape. Its central spine would connect many nodes of density, functioning as centres of commerce and production, with high-rise living. There could be 20-odd nodes between Whangarei and Hamilton.

This is what we call the “working city”. In contrast – the “lifestyle city” would be situated on the glorious east coast. We see it as part of the larger “NZ Riviera”, stretching from Whangarei to Whakatane. Here, the world-renowned qualities of Auckland’s superb suburban lifestyle would mature to the level where Auckland would truly become the “world’s lifestyle capital”.

New infrastructure technologies, such as localised sewerage and water systems, super-efficient solar panels, internet and electric cars, mean that any new urban settlement is not necessarily reliant on expensive centralised infrastructure systems. We no longer have to get our power from the South Island or by burning fossil fuel, and we don’t have to drive two hours to work.

If this sounds a bit like science fiction, that’s because it literally is science fiction. The ur-form for the linear city – and its most complete expression – is a 1975 utopian science fiction novel by Ernest Callenbach: Ecotopia.

Ecotopia imagined an environmental utopia in a future US West Coast that had seceded from the rest of the country. Urban space and economic life have been upended: the new nation has pursued radical decentralisation and sustainable living.

Bogunovich and Bradbury don’t go as far as Callenbach in calling for an end to investment capital, radical downsizing of central government, and a ban on all cars, but they do harp on many of the same themes when it comes to transport and urban form. In the book, for example, San Francisco has been downsized to a mere village, its population spread out into “minicities” on rapid transit lines:

the great concentrations of people in San Francisco, Oakland, Portland, Seattle, and even the smaller metropolitan areas began to disperse somewhat. New minicities sprung up in favorable locations, with their own linkage necklaces of transit lines: Napa, on its winding, Seine-like river, at last pollution-free; Carquinez-Martinez, stretching out along rolling hills dropping down to the Strait; and others throughout the country.

Bogunovich and Bradbury echo Callenbach’s language when they speak of a central transit spine connecting “many [small] nodes of density”. It’s a seductive idea. But, as public transport guru Jarrett Walker pointed out in his review of Ecotopia, it’s an intrinsically unworkable one from a transport perspective:

A gleaming high speed rail system delivers his hero through a transbay tube to an intimate, shrinking village called San Francisco. But real transbay tunnels and high speed rail require major cities to create the demand around their stations. Those cities need the big infrastructure of power and water and transit. That infrastructure may sometimes require cutting down some trees, accepting the impacts of a dam, building densely where somebody already lives, or creating space for efficient movement on a street that could otherwise have been a park, a creek, a kiosk, a gathering place.

The contradictory, fantastical nature of Bogunovich and Bradbury’s vision becomes even more apparent when we consider the real-world examples they cite for Auckland to follow. These places, they argue, combine a low-density linear form with highly efficient rapid transit and natural amenities:

Frankfurt is a famous example of a super-efficient city that consists of more than 70 local authorities. It prides itself on its inclusion of agriculture into the metropolitan fabric, its first class, evenly distributed, recreational green open spaces, and international airport amidst a forest, which serves three major cities.

Other famous models of successful, decentralised and polycentric development are metropolitan Munich and the urban region of the Ruhr. Both cover large areas, include plentiful open spaces, and have managed to contain urban sprawl in the form of a coherent polycentric pattern.

Let’s take a look at these places. Here’s a map of the Ruhr region. According to Wikipedia, the region is home to 8.5 million people – over five times as many as in Auckland. From end to end, the main urban corridor – from Duisberg to Dortmund – is around 80 kilometres long. That’s about the same as the distance from Pukekohe to Silverdale.

So if we wanted Auckland to be more like the Ruhr, we would have to increase the population of urban Auckland fivefold. That’s a level of intensification far, far beyond anything contemplated in the Unitary Plan.

We run into similar problems with Frankfurt and Munich, which are roughly comparable in population to Auckland but considerably denser. Charting Transport has helpfully published comparative data on population-weighted densities in Australian and European cities. (Population-weighted density is the most accurate measure of density – it measures the density of the neighbourhood the average resident lives in.) According to that data, Frankfurt is twice as dense as Melbourne, and Munich is almost three times as dense. (Auckland and Melbourne have pretty similar densities.)

For the visual learners, here’s a randomly selected neighbourhood several kilometres from the Frankfurt city centre. Observe how this kind of medium density would be totally illegal under existing Auckland planning rules:

So rather than making the case for a sprawled “linear city”, Frankfurt, Munich, and the Ruhr illustrate Jarrett Walker’s point that population density is necessary to obtain efficiencies in infrastructure provision, including well-utilised rapid transit. Those cities have developed intensively where there is demand to do so, especially in inner-city suburbs. As data on infrastructure costs for low- and high-density developments in Auckland shows, this can save money:

Bogunovich and Bradbury’s problems in distinguishing between science fiction and reality get worse when they start discussing Auckland’s existing urban form and infrastructure. They argue that:

Being located on a land-bridge, Auckland has mainly grown in the northern and southern directions. After 100 years of growth and amalgamation, it has grown into a linear conurbation some 70km long. By 2040 it could be 150km long. This is not bad news; linear cities are famously efficient.

Are they really? As Bogunovich and Bradbury concede, Auckland already has a relatively linear urban form. If this does indeed improve efficiency, shouldn’t we already be reaping the benefits in terms of lower house prices and more efficient transport outcomes?

Or, to put it another way, isn’t continuing to do the same thing and hoping for a different outcome the very definition of insanity?

In response to this concern, Bogunovich and Bradbury say that they want to continue doing the same thing – urban expansion into nodes up and down State Highway 1 – but differently in an unspecified way:

Growth is already happening along this corridor anyway – witness the boom in Te Rapa, Pokeno, Silverdale and Warkworth. However, this development is haphazard, exacerbating traditional urban sprawl and commuting distances. It also relies too much on expensive and vulnerable infrastructure.

This is also very problematic: they don’t provide any specific explanation of how their linear city would differ from the one that actually exists. This has serious cost implications. As Auckland Council found when devising a “Future Urban Land Supply Strategy” last year, urban expansion is expensive. They are expecting network infrastructure costs to rise to $100,000-$200,000 per dwelling for greenfield development.

In Bogunovich and Bradbury’s vision, “distributed, small scale, clean, green and smart infrastructure” would bring down these costs. This, again, echoes the science fiction world of Ecotopia. But without details – or better yet, costed and implementable plans – “technology will transform the way we live!” is an empty slogan. It means nothing.

Their discussion of the transport and labour market implications of a 150-kilometre long linear city “that extends at least from Wellsford and Helensville to Pokeno and Orere Point” is equally unsatisfying. They state that considerable horizontal expansion will lead to lower, not higher, transport costs: “we don’t have to drive two hours to work”.

For this to work, it would require people in the outer nodes to work locally, rather than commuting to other areas of the city. That would represent a significant change from the way that Auckland (and every other large city) works. At present, people who live further out commute longer distances, on average:

Previous attempts to decentralise the city have not changed this pattern, because it is intrinsic to the way that urban labour markets work. As former World Bank urban researcher Alain Bertaud observes, normal cities involve people commuting between a lot of different points, which enables the agglomeration economies that make cities work. An “urban village” model, in which everybody commutes short distances to the nearest “node”, occurs in planners’ dreams but never in real life:

This isn’t to say that Bogunovich and Bradbury’s ideas are all bad. Given Auckland’s geographical constraints, there is a good case to build a better rapid transit network focused on key corridors with high demand. That’s exactly what Transportblog has proposed in its Congestion Free Network, and it’s what Auckland Transport is planning to build:

Enabling more housing in areas that have good transport accessibility is also a good idea. In fact, that is exactly what the Unitary Plan’s Regional Policy Statement says should happen:

2. Enable higher residential densities and the efficient use of land in neighbourhoods:

a. within and around centres and within moderate walking distances from the city, metropolitan, town and local centres

b. in areas close to the frequent public transport routes and facilities

c. in close proximity to existing or proposed large open spaces, community facilities, education and healthcare facilities

d. adequately serviced by existing physical infrastructure or where infrastructure can be efficiently upgraded.

But, as I’ve explained above, the vision of Auckland as an exclusively “linear city” simply isn’t grounded in reality. It may be fine as science fiction, but it would fail in practice.

In fact, the examples chosen by Bogunovich and Bradbury make that very clear. Auckland’s low-density, linear urban form has led to our current housing affordability and transport problems. The German cities, which are much more densely populated, have been more successful in avoiding those problems. Emulating them would mean allowing more mid-rise housing to be constructed near the centre, not less!

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