Severance is an urban design term term used to describe separation effects on a place caused by some obstacle of scale. Also know as The Barrier Effect. Sometimes these barriers are political and the severance intentional; a physical attempt to keep people in or out or just apart. Obvious examples are the Great Wall of China, the new wall in Palestine, or like below; the Berlin Wall.
More usually Severance is caused by human constructions such as canals, rail lines, or even cultural things like historic palaces or big city parks. Sometimes in the second group the severance is intentional such as in the construction of walls and battlements. Other examples include large industrial plants, military bases, or any other massive interruption.
Severance generally causes cost and inconvenience to a place and difficulties to both commercial and social transaction. But, and especially when it caused by natural landforms, it may lead to defining the quality of a place through both its separation from other areas and by concentrating activities and business. In fact many cities owe much of their form and even their identities to the effects of containment by local geographical features [Venice!], and others suffer from a formlessness allowed by the easy spread into a surrounding countryside free of natural barriers [Phoenix, Las Vegas].
Wellington is a local example of the first group, the strict containment by steep hills and wild seas has done much to keep it compact and define it. Where as Christchurch can be argued to have suffered from a lack of shape and intensity because of its easy spread onto the surrounding plains.
There are significant differences between natural and artificial Severance. The presence of the former may in fact be the very reason there is a city in this place at all; a harbour, a river, a hill. And the construction of bridges or tunnels to breach or cross these obstacles will be important moments in the story of these cities. But the construction of something that causes Severance as a by-product of its main purpose is another thing all together. A common cause of separation is transport infrastructure such as rail lines, highways, ports, and airports.
Here Severance can usually be considered to be a dis-benefit of a particular project, and ideally care will be taken to ameliorate its affects. But this doesn’t always happen, especially because it will almost always add cost to a project and in the excitement of a new technology side effects are often just ignored. Like in the railway mania of the 19th century; a great many cities were violently affected in the name of progress by this new system. Here’s the first exception:
There is a considerable irony when severance is caused by transport projects. Projects whose primary aim is to improve connection. This may simply be a case of the privileging of one kind or direction of movement over another [say highways over local roads], or the valuing of one type of place over another [distant commuter suburbs over older innercity ones]. Or the combination of both: a sacrificing of quality of place to quality of movement [Auckland's motorways were sold in part as slum clearance].
This issue is particularly evident in Auckland, so much so that it clearly deserves the title: Severance City.
By forming an almost complete moat around the city’s CBD mightn’t we reasonably expect a mini-Manhattan effect from this isolation; an intensification of habitation, commerce, and construction within this area in response? Well it hasn’t happened yet at least in part because of the particular conditions of motorway severance, discussed below, but interestingly this may be something that can be improved by reducing the CBD’s exposure to the negative effects of this severing Ouroborus. So long as we invest in fixing it.
Because the motorways around the CBD are not only delivering vehicles to and from the city, but also carry an enormous amount of traffic heading elsewhere, are in fact the core of the entire region-wide road system, it means they are of a scale and complexity that makes them a formidable barrier. Even where they are crossed with bridges it makes for a long, exposed, and unappealing journey. So walking or cycling to and from the inner suburbs that survived the motorway construction is considerably affected by their presence.
And because the construction of this system was co-ordinated with the removal of the well used tram system and, until recently, the managed decline of the passenger rail network it has also perversely left the CBD’s condition dependent on a daily flood of vehicles onto its older city streets. Which of course has had a profound effect on the quality of life and place there as well as its effectiveness as an economic centre. So much space and building goes into car parking and distribution throughout the CBD that the condition of the motorway system has become synonymous with the city itself; despite being isolated by this system it is also hostage to it: Not just Severance City but also Congestion City.
In order to improve the quality and performance at the heart of our biggest city this phenomenon needs to be addressed, both by re-stitching the links across the divide but also by reducing the impacts of auto-dominance within the ring. So it is not simply a case of putting more road bridges across the motorways, in fact there is nowhere that these could go, but rather we urgently need to build more capacity across the motorway severance that doesn’t add more vehicles to city streets; and in fact allows us to reduce their numbers.
And there is no scheme that can do this as well as the City Rail Link. As virtually every city of scale on this planet has found, the best way to enable an urban centre flourish, and with it its wider region, is to connect it with its hinterland in a way that doesn’t destroy either in the process. Linking up our existing rail network under the motorway will be a transforming solution to this problem for the CBD as well as the wider city as both will be connected through this divide. As Matt illustrates so well below; the width of the arrows indicates capacity.
But it is also clear that effort must go into repairing the links across the motorways. To that end, along with architect Julie Stout, I am running an Advanced Design Studio at the School of Architecture this semester where we have 15 bright young architects to be coming up with creative ways to repair the damage caused by the motorway craze of last century. Hopefully they will have some great solutions and I look forward to getting some of them to post them here once the year is over.
Just imagine being able to walk from Wellesley St street to the Domain again, or a direct route from the new Parnell train station to the University, or to be able to get across Fanshaw Street alive…..