The City of Brasilia, conceived and built in the 1950's and 60's, is the exemplar of modernist urban planning. It's got it all: extreme separation of uses, access only by motor vehicle, mid-rise boxy buildings set in vast open spaces, and a conspicuous absence of any history before the mid-twentieth century. There are no traffic lights or sidewalks in the city (at least in the original design), and almost every four-way intersection is a cloverleaf interchange. The design ensures that motorists will never have to inconvenience themselves by stopping, and pedestrians don't mind because they theoretically don't exist. It all fits together like a machine - actually an airplane, by resemblance.
But when the city is viewed from above we can see incursions of organic human life superimposed on top of the plan. The picture below is near the center of the city, where the wings meet the fuselage of the plane. A network of paths are clear evidence that pedestrians have crossed the open field where they are not suppose to.
These rogue pedestrians don't have an easy task. Virtually the only way to access this space is to cross at least six lanes of traffic and then cross another six lanes to exit. The width of the open space is 1/4 of a mile, which is exactly twice the width of the national mall in Washington D.C., and there is no shade or amenities whatsoever. They still make the journey.
Drawing the human use on the map reveals a complex network of activity very different from the plan.
This is the network of function over geometry. The paths are trodden out of convenience, but they also gently meander. Lewis Mumford recognized this unviersal tendency back in 1961, just as Brasilia was under construction.
"the slow curve is the natural line of the footwalker, as anyone can observe as he looks back at his tracks in the snow across an open field."Not only do the curves shift the field of view slightly offering some aesthetic variation, because of topography they can even be the most energy-efficient route. (Unless, that is, you have a bulldozer to eliminate all preexisting topography.)
Although it's hard to prove conclusively, it looks like safety concerns played a part in determining where the highways were crossed. Several paths seem to converge at points where on-ramps and off-ramps are separated from the main flow of traffic. Crossing at these points allows the pedestrian to have breaks of median before having to make the next step. It looks as if some people have been willing to sacrifice a certain degree of time in order to cross a little more safely at one of these points.
Interestingly, these points of convergence are analogous to the forces that led to the origins of medieval Paris. The only difference being that Paris was formed at the easiest crossing point of the Seine river, where an island reduced the distance, and residents of Brasilia are attempting to cross a river of automobile traffic at a breaking point. If I were in the hot dog stand business (and it were allowed) I'd know exactly where to set up shop.
Lewis Mumford explained further what he admired in medieval cities,
"Organic planning does not begin with a preconceived goal; it moves from need to need, from opportunity to opportunity, in a series of adaptations that themselves become increasingly coherent and purposeful, so that they generate a complex final design, hardly less unified than a pre-formed geometric pattern."yes, this happens even in Brasilia.