The walking paths of Brasilia

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.

Visualizing 3D Cities one building at a time

Philadelphia Skyline from Google Building Maker

The folks at Google have set for themselves the ambitious goal of modeling every building on earth. Rather, I should say that we have been given this challenge. On Tuesday, Google launched a new tool, Google Building Maker, that allows users to create a simple three-dimensional outline of structures and map aerial photos onto it. If Sketch-up is the powerful modeling tool, this is the quick and dirty method of populating the world's cities with complex texture. From the looks of Philadelphia this evening, only three days into it, these cities will be growing quickly. I modeled the Philadelphia Museum of Art pictured in the foreground, but someone else beat me to it. Many of the individual houses in the surrounding neighborhood are already completed.

The tool isn't perfect. Trees that obscure the sides of buildings get mapped onto the structure itself. Complex buildings with ornamentation are difficult to capture. However, Building Maker integrates nicely into Sketch-up, allowing these inconsistencies to be improved with time.

Some Car-free Zones

I've been browsing through the wikipedia list of car-free zones around the world and reading about some of them at Carfree cities. Here are some overhead shots courtesy of Google Earth.

Plenty of pedestrian areas in Europe are preserved sections of the originally walled medieval town. Gronginen is a university town in the Netherlands. About 30,000 people live in the car-free area.


Fes-al-Bali is a medina in the city of Fes, Morocco, also of medieval origin. It's probably the most populous area without automobile use in the world.


There are also some new communities that prohibit private cars. This is Discovery Bay on Lantau island across from Hong Kong. About 14,000 people live here and it is still in the process of development.


Curitiba, Brazil is considered to be a model for transportation planning. About 20 blocks in the center of the city are for pedestrians.


A few cities in the United States have created small pedestrian malls in their centers. One of the best known is the River Walk in San Antonio, Texas.


This is Last Chance Gulch in Helena, Montana.

Missoula's public planning data

As a Google Earth junkie and an armchair planning enthusiast, I was pleased to find that the city of Missoula offers some Google Earth overlays with transportation data - various borders and traffic counting stations. A separate overlay features some of the projects on the slate for the next few years.

For example, I found that the the traffic into my neighborhood, the lower Rattlesnake, has actually declined a little since 2004, after two decades of steady increases. I wonder if that is just a statistical blip in the data or if it points to a meaningful change. I know that development in the Rattlesnake has certainly not declined.

Imagine how free software like Google Earth could revolutionize the public involvement in land use and transportation planning. All of us could play the planner with a wiki-style interface, and local governments would have substantial insight into the wishes of their constituents. This is a good start.

Geometry of Capitals

The abstract concept of a modern nation-state calls for nothing other than abstract geometrical patterns for the nation's capital.

The Hexagon of Canberra, Australia (1913)
Planned by Walter Burley and Marion Mahony Griffin of Chicago.


The Triangle of New Delhi, India (1929)
Planned by Edwin Lutyens under British colonial rule.


The Airplane/Butterfly of Brasilia (1956)
Architect Oscar Niemeyer insisted upon butterfly, but most people see an airplane.


The Oval of Yamoussoukro, Côte d'Ivoire (1983)


The Rectangle of Astana, Kazakhstan (under construction)
Astana is fascinating. Newly acquired oil money is fueling some of the most opulent architecture in the world way out in the isolated steppes of northern Kazakhstan.