I’ve been following the dialogue sprung by Planetizen’s recent post on urban grids: Beloved and Abandoned: A Platting Named Portland. The article is an evaluation of the regularized urban grid as exemplified by Portland (200’ sq.’ blocks). The article concludes that Portland’s grid just doesn’t succeed against the contemporary criteria of efficiency and the related tenants of sustainability and bottom-line cost. For a local, Portland response to this urban planning evaluation see Landscape and Urbanism
Beloved and Abandoned doesn’t focus much attention on the origins of urban grids or how they perpetuate themselves within the city, and the discussion of the feel or aesthetics of of the city is minimal. The formal grid is discussed in relation to its assumed opposite—the medieval and the labyrinthian:
“As a drawing, the plan has a feel of flawlessness, the appearance of perfection, particularly in contrast with labyrinthine medieval town plans or recent bewildering suburbs. When this perfection is combined with a pleasant experience on the ground an indissoluble match is made…Coupled with connectivity, its rectilinear geometry is indisputably more advantageous for navigation on foot, car or bike than any alternatives. Visitors often feel lost and disoriented in medieval towns and in contemporary suburbs and this feeling leads to anxiety and even fear and a sense that all is not well.”
In the F.A.D. mode of exploring constrasts to Portland, and as a counter example to the modern efficiency approach and the notion of confusion driven anxiety emerging from a lack of straight lines, consider the city of Guanajuato Mexico.
The city was founded by the Spanish Conquistadors as a mining town for Silver, which dictated the siting of the city and also dictated that the city would not conform to nearly any of the urban planning ideals set forth by the Spanish crown in the laws of the Indies (in particular the Spanish desire for rectilinear gridded cities). Guanajuato is built into the steep valleys of the Guanajuato river valley, with the curves of the river forming its central spine. Prone to flooding, the city built upward along the banks of the river but continued to be repeatedly flooded. Rather than taking a hint, the city responded by getting more proactive in its engineering. The Guanajuato river was eventually dammed and re-routed in tunnels beneath the city where it still runs today.
The Guanajuato region is still economically dependent on mining, but the city itself has expanded and diversified. The provisional curvy grids of the mining town became the lasting structure of the city…the urban “first causes” (a la Aldo Rossi) that remain long after the conquistadors. Over time this structure has been extended and attained more complexity than the initial framework.
In the image above you can see a dotted line of one of the subterranean roads that travel beneath the city. There are miles of these tunnels beneath Guanajuato, some of them occupying former channels of the river, others dug through the earth to pass through the steep surrounding hills. These roadways meander in the same way as the on-ground grid.
I had the opportunity to spend time exploring the city as part of a design research grant in 2005. Below are some images from that research.
Sunken street with elevated housing to avoid flooding from the river before it was dammed and rerouted. A fascinating element of walking around the city is the way you often are unable to to tell what “at grade” is due to the vertical pairings of the grid combined with the density of the surrounding structures.
Guanajuato is one of the most fascinating cities I have ever walked. Similar to London, Venice and medieval villages in northern Italy, the fascination lies in the curiosity sustained by never knowing what’s coming next , the sense of the cruise, the derive . You have to pay attention to the city or you do get lost until you physically know the place. This is an asset to a city rather than a liability. The city’s convoluted complexity creates local-specific knowledge rather than placelessness, in contrast to grids that privilege efficiency over other factors.
And the irony for Guanajuato is that the grid form is largely unintended. The boiled spaghetti networks were a result of natural features; a grid that was not all that respectful of those features, yet one that by necessity had to meld its evolving infrastructure around it. And as was already mentioned elsewhere, unless we are building another Curitiba or Canberra, we inherit grid structures we have to work with, rather than invent. And these early, formative structures have a tendency to autonomously elaborate or continue to build themselves. Like nearly all other cities Guanajuato has incrementally evolved through near limitless non-coordinated intentional alterations, yet still retains its physical structure.