A Savannah in the Desert?

An Odonomy of Savannah VII: A Tale of Two Grids

~ part ii ~
inertness and porosity

Of all the random, visually interesting development patterns I've stumbled across on Google Maps, the trailer/RV parks of Mesa, Arizona sure compose some intriguing aerial ruminations. Unlike the garden a la francaise interests that sometimes appear in aerial photos of suburban subdivisions, what strikes me most about Mesa's patterns are the rectilinear and simple geometries they playfully vary in Mesa's half-mile arterial grid fabric. Here are examples of what I mean:







The brutally efficient compactness of these trailer park patterns, jiggling and permuting different ways within their self-absorbed perimeters, makes one's eye squint a bit at the optical glare produced. Indeed, the bright roofs of the densely packed units are a noticeable feature of Mesa from earth orbit. The bright band in the center of the Mesa area aerial below represents these trailer parks from on high, which are abutting Mesa's Main Street/Apache Trail east-west artery, cutting right between a contrastive greenish swath of sprinkler-squirting Arizona subdivisions:

One can't help to wonder if these trailer parks reflect a lot of solar radiation away from the Phoenix area, and one even suspects a collective recoup here of sorts in lieu of Mesa's heat-island contribution to net global-warming impact. I wouldn't even be surprised if they also help make up for that indeterminate bit of glacial retraction and polar snowmelt that Mesa's emissions produce.

Regardless, I, of course, can't help but to notice the formal similarity between these developments and a Savannah Ward.

Here, for example, is a typical Mesa/Apache Junction trailer park development:

Compare with a (more residentially comprised) Savannah Ward...

For the heck of it, here are other variants of Mesa's trailer parks:

In the above examples, notice that the community/leasing complex usually in the smack center of the development appears as a staple Mesa trailer park amenity. Notice also the way the main drive of the development ties head-on to the complex, much like Savannah's signature north-south streets that lead directly (and encircle) the garden squares. Moreover, these entrance drives tend not to be loading streets, but what I define as "avenue" types that channel travelers directly (and sometimes ceremoniously) to destination points as their predominant function. Of course, the Mesa developments are much larger than a Savannah Ward, up to six times in size even, but the shared community amenity is, very interestingly, roughly the size of a Savannah garden square.

What's most interesting to me about the above comparison, however, is the near similarity in dimensions between Savannah's original town lots, which vary slightly more or less than 60'-0" by 90'-0", and a typical Mesa trailer lot, usually sized around 55'-0" by 80'-0". In some locations, Mesa's developments even have what appear to be woonerf-like open, semi-shared "backyard" spaces in the block interiors (between the rows of mobiles), a tantalizing equivalent to Savannah's intimate residential service alleys. While it, of course, developed more densely and compactly over time, Savannah's present form has evolved out of town lots just a little bit bigger than these Mesa trailer lots. In fact, in some of the more residential squares, Savannah's lots have subdivided further into lots much smaller than the trailer lots, but in a hardly noticeable manner. It's hard to imagine that two or three stately Savannah Victorians can fit in an area not very much larger than a Mesa trailer lot, but they do...and this they do in Savannah with a kind of quiet, comfortable manner that brings added intimacy to their street-setting:

The three detached Victorians on the left share what was originally a single 60' x 100' Savannah town lot

All this begs the intriguing question, could Mesa evolve over time into a kind of "desert" version of Savannah?  Well, if you just glance at the image of a Mesa trailer park by Flickr poster kevindooley (at the top of this post), one can easily begin to imagine suggestive possibilities for a desert-scaped woonerf.  (Why, my landscape urbanists out there in AZ, just turn that couch into a Diller Scofidio park bench and you're already 50% of the way there!)  Unfortunately, the challenges for such a transformation are more daunting than that, of course.  Which brings me back to a critical asset of Savannah's "Two Grids".

I mentioned in part i that Savannah has two literal overlapping grids.  One primary grid handles most of the vehicular traffic work-load, and serves as Savannah's equivalent for Mesa's half-mile segmented arterial grid.  But the other grid of Savannah, which handles the local traffic and much of the ped/bike movement, is not just a discontinuous local/collector/service network but, in great distinction with Mesa, is a true grid, which holds its own integrity from ward to ward.  Savannah's contiguous secondary grid is the unique asset of its form, a profound quality of Savannah's form worth interrogating and experimenting with in our form investigations for cities.  The two-grid system synthesizes Savannah's economic diversity to the very specific circumstances of its public realm and harmonizes its transformations.  

In part i, I went so far as to claim that Savannah's fabric is "open" in its synthetic function, in that uses and their interrelationships are not pre-determinately set or stiffly delimited and are seemingly allowed to transform over time, in distinction to top-heavy and ready city planning approaches. But, I'm realizing "open" might be a bit of a misleading term, and misapplying the takeaway, if one interprets this modifier as "randomizing" or politically-neutering the act of development or, even more, as contemplating some theory of libertarianism.  Rather, I dealt at length in that post with exactly the more mundane and determinate exertions of Savannah's form on land use and transportation decisions in Savannah.  The truth is, Savannah's form must be socially negotiated continuously, as all inhabitants must in every city, but, what is somewhat novel, is exactly how Savannah's system-like form "tunes" and harmonizes these negotiations.  Form and negotiation travel here hand-in-hand in a noticeable way, and both build upon each other.  They make Savannah's invisible "rules" of city transformation legible to the historically reflective eye.  Today, however, Savannah's form has closed like a trapdoor on itself, at least to conditions of transformation in our time scales of experience.  Historical preservation priorities have reinforced this.  A harmonized stasis it might be, but a stasis nonetheless for our present-day vantages of development.  In this respect, we may look with interest at Mesa's potential to urbanize.

Unfortunately, Mesa's discombobulated collector/local/service street fabric exerts a dubious influence on its potential for Savannah-like urbanization.  These small-lot trailer park conurbations are not likely to see any evolutionary development along the lines of Savannah's historical trajectory (even if these fabrics made urbanistic sense - which they don't, really, but I won't treat that topic in depth now). Simply, Mesa's private street networks only serve the abutting users of the street; they do not avail themselves to the greater traffic of the city. This is by no means a trivial distinction. Not only that, but these developments often have a single and highly controlled point of entry, their sole link to the primary grid.   They might as well be gated entry, conventional garden apartment developments, and their only likely fate is to be likewise redeveloped wholesale once their conditions of deterioration become unbearable.

In Savannah, small-grain local negotiations produced gradual urbanization and gave birth to land use diversity, but Mesa's single-use developments and disconnected private fabrics transform only with transactions involving what Jane Jacobs called "cataclysmic money": upon the decisions of leveraged landholders somewhat removed from any slow-forming communities that they might impact.   Savannah's land use diversity evolved under conditions of "porosity" both of travel and of capital flows, catering to locally modulated conditions of access, adjacency and travel pattern in ways that guaranteed that local investments would need to weather the test of time.  But such conditions are not permissible in a Mesa trailer park, both due to the lack of its users' agency in land-investment decisions and their sole dependence on vehicular links to employment and consumption resources that lie outside of the development.  Their money, whose source is more than likely from the outside, likewise travels only in one direction: outside.  It cannot be invested within except to be immediately consumed or parked there intermittently on wheels.  Their interests (and hopes) lie elsewhere.  Their TV's and iphones guarantee it.  Mesa, simply, has too much flux within and without and the inert edges between inside and outside are its most stable condition.

What would happen if this street had more cross connections?...

View Larger Map


Might intermittent residency, economic disadvantage, social powerlessness and isolation continue to haunt Mesa's trailer parks? Might they see their trailer lots become individually owned investment assets? Might they connect their wealthy, land invested neighbors to the north and south of them in interesting ways to create the ripe connections needed for urbanizing Mesa's "Main Street" from a drive of strip centers to vital centers that can also concentrate social capital?

What are the inert conditions that are responsible for this?...

Mesa's Crime Rate Map ...Not just bright from space.