Which street pattern represents your continent?

When I was two years old, my family moved from the Bay Area to Northampton, Massachusetts. My earliest memories are from there and it is one of the three or four places I usually claim as my hometown.

My family loved Northampton, and even after moving away, we would make regular pilgrimages back every few summers or so. I really wasn’t sure what I liked so much about it until I went to urban design school, but now I know part of it was the organic street grid. Each block feels distinct, and the slight curves of the streets create outdoor rooms, while the density of the street network allows multiple ways to get to your destination.

Unfortunately, the organic street system, common in other parts of the world, is a rare thing in the US and Canada. I decided to take a look at the major cities of Anglo-America and see where I could find organic cities. But first, here are the general characteristics of the street patterns I found:

Gridiron

Gridiron streets are among the simplest to design. Simply lay out a series of streets at right angles, forming either square or rectangular blocks. Often, but not always, the blocks are all the same size.

Grids represent power and organization. Whether that power is political, as is the cases of the Roman colonies or cities of the Soviet era such as Almaty, Kazakhstan; religious, as in the cases of Philadelphia or Salt Lake City; or commercial, as in the case of hundreds, if not thousands, of towns laid out in grids parallel to a railroad track or radiating from a central factory, grids almost never arise piecemeal.

Many cities with grids at their center may have non-grid patterns outside of their centers, whether these be the organic slums of the developing world or the suburban cul-de-sacs of Anywhere, USA. By the same token, many cities with other patterns at their center may also have gridded areas, such as Boston’s Back Bay. One example I like to discuss is Pittsburgh (one of my other hometowns), where extreme terrain keeps a grid from being applied all across the city, but they developed in each neighborhood, such that Downtown, the Cultural District, Strip District, the Bluff, and most other neighborhoods all have their own grids which sometimes collide in interesting or confusing  ways. In Pittsburgh, when a street curves, you know you’re entering a new neighborhood.

Organic

Organic streets go every which way. They start and end, seemingly at random. They curve back and forth. Ideally they still form a dense grid of streets, but not always.

Organic streets can come from disorganized, fast-paced development, as is common in today’s slums: or it can grow slowly over time, as one plot of land is divided and streets are built over the new boundary, like many of the old towns of England and other European powers. However, in The City Shaped, Spiro Kostof makes a point that organic cities are not necessarily unplanned. Far from it; they are planned most sensitively, one building or parcel at a time. Kostof also points out that the seemingly random lines of organic streets may actually be anything but: they may follow contour lines, political divisions, watercourses, or other features.

Loose Grid

The loose grid is sort of a compromise between the two systems above. Streets mostly come to four-way intersections as with the gridiron, but they may curve and shift gradually as with the organic.

The loose grid fills the spectrum between gridiron and organic. In many cases, it is a sort of transitional form that goes both ways. A city that starts on a strict gridiron plan can, over a long time, decompose into a more organic pattern, as can be seen with the many cities in Europe that started as a Roman colony and then became more organic during the middle ages. Conversely, a pattern that started off more organic can become regularized and formalized to form a more grid-like plan. This can be seen in Lower Manhattan, where the ghost of the original grid can be seen in the curing streets, but intersections have become regularized over time and streets are fairly evenly spaced, despite their curves.

Radial Grid

The radial grid is a gridiron plan on steroids. It is strictly geometric, regardless of existing topography, and in some cases changes the topography to better match the geometry. If the gridiron represents power, the radial grid represents power without subtlety: streets radiate from churches, palaces, state buildings, and other emblems of authority.

The radial grid takes much more skill to design and implement than the standard grid, and as such is much more rare. It is often seen in the palatial estates of Europe, as at Versailles and Karlsruhe, and in capitals both democratic and colonial, as in Washington, DC and New Delhi.

Rarely implementable on the scale of an entire city, many cities have sections with radial grids. Paris, an organic city, had parts of it wholly demolished in the 19th century to be redeveloped in grand radial style. Though it retains its overall organic pattern, grand boulevards such as the Champs Elysees link powerful monuments such as the Tuileries and the Arc de Triumph across the organic fabric.

Suburban

When I say the suburban pattern is less common, I mean in the center of cities or towns. Overall, the suburban pattern is probably the dominant one in Anglo-America, but rarely do cities of this pattern ever grow to considerable size.

Suburban streets are built for cars, and they are built hierarchically: local streets, built for few cars, connect to collector streets with more cars, which further connect to arterial streets which carry even more cars. Blocks, if they exist at all, are exceptionally large. Higher level streets may form loose grids, or in some cases even a strict gridiron, but local streets, in an effort to discourage through traffic, are made of loops and cul-de-sacs. These streets curve, sometimes following topography, but more often than not simply to create a faux-organic feel, but developed quickly and on extremely large scales, these places are anything but.

I am doing my best to control my anti-suburban rants, but they are in many ways toxic places. Rather than explaining why here, I would refer you to the book Suburban Nation.

These are the street patterns I found looking at the top 50 cities in the US and Canada. And what pattern did I find most common?

US and Canada:

I looked at the top 50 cities in the US and Canada, and overwhelmingly they are gridiron cities. of the 50, 38 had this pattern.

This probably has to do with the fact that American cities are colonial cities. Many of them were designed to expand quickly and accept a large volume of immigrants in a short amount of time, and the unsophisticated, unnatural, yet highly effective gridiron facilitated that development.

The next largest group, at 5, were loose grids. Of these, New York and Montreal seemed to be formalizations of previous organic street systems, while the other three were gridiron plans adapted, minimally, to topography.

Three cities on the list actually had suburban patterns at their centers. In all three cases, however, these cities were not the center of their relative metropolises; rather, they just happened to be particularly large suburbs of even larger cities.

Radial grids and organic street patterns each had two. The radials included Washington, DC’s baroque avenues, as well as Detroit, which was originally platted with triangular blocks that came to six-way intersections with streets every 60 degrees. However, this plan was barely implemented beyond the Campus Martius.

The only organic cities were Boston and Quebec City. I’m not sure what makes these two unique, beyond possibly their initially constrained footprint. Boston 350 years ago was nearly an island, with today’s Back Bay and South Boston being built almost entirely on fill. Quebec City was one of a very few walled cities in the Americas, and the original core within the wall retains an organic pattern. It may be that other cities in America, where such constraints did not exist, felt a need to plan for quick expansion, which is easily accomplished by a gridiron pattern.

So America really isn’t the place to look for organic cities. But the general consensus is that Europe is chock full of them. So I looked at the top 50 cities in the European Union and found the following.

Europe:

Sure enough, 35 out of the top 50 are organic.

It is interesting reading Kostof’s history of urban deveopment, where among other things he discusses how the gridiron plans of Greek and Roman colonies decayed into organic patterns over thousands of years and even more small transactions of property. Who knows, in a thousand years, and possibly with the decay of existing power structures, Kansas City may look like Vilnius.

Thirteen of the remaining cities showed loose grid patterns. These cities were located all over Europe, but were strongly concentrated in the east, especially Poland. Many of Poland’s major cities took a lot of damage in World War II and were rebuilt under Soviet control, so old patterns could easily have been regularized in the new regime.

Only two of the top 50 showed gridiron plans: Turin and Glasgow. Both of these are much younger cities than the others on this list, having really come into their own as factory towns of the early industrial era. With the emphasis on mechanization in that era, it is not terribly surprising that these cities would look like their parts were mass-produced.

If the difference between Anglo-American cities and European cities is simple grids that facilitate fast development versus millennia of organic development, then what do the cities of colonial Latin America look like?

Latin America:

43 out of 50 cities in Latin America featured a loose grid.

This is largely due to the rule that governed colonial Spanish development in the Americas: the Law of the Indies. This law proscribed how to lay out the main plaza, major buildings such as the cathedral and the palace, and a grid of a few streets. In many Latin American cities, there is a fairly strict grid at the very center, but it quickly relaxes only a few blocks from the Plaza Mayor.

Four of the top 50 cities in Latin America feature gridiron plans. The three of these settled by the Spanish, Guadalajara, Puebla and Asuncion, could theoretically just have been a lot better about implementing the Law of the Indies. The fourth, Belo Horizonte, has an interesting and unique city plan. It is based on a regular gridiron plan with square blocks, but radials at 45 degrees overlay that base to form a supergrid. Although this plan looks very interesting from above, I wonder if this city experiences the same issues that Washington, DC faces with the difficulty of developing triangular blocks and difficult intersections with as many as eight legs at a juncture.

Of the final three cities, two were organic and one was radial. I don’t know enough about the history of Sao Paulo to explain why it has an organic street pattern, and would invite anyone who knows more than me to explain why in the comments section. La Paz is a little easier to read. It is located high in the Andes Mountains, where the topography makes it difficult to implement a more geometric grid pattern. Goiania, the only radial city in the group, has a series of public spaces from which streets radiate and ripple.

Well, I’ve done three continents already, so I might as well finish the bunch. Asia, what have you got?

Asia:

I only did the top 30 cities in Asia, because that list was easier to find on Wikipedia. Of these 30, 22 had organic street patterns.

Although many of these are ancient cities, it’s not like they never experienced colonialism. But what you see in many of these cases is an organic core, and then a region of more geometric development, which is a colonial or foreign quarter.

Five of these cities showed a loose grid pattern. These grids tell a variety of stories. For instance, in Shenzhen and Shenyang, a supergrid of highways is filled in with slightly looser development, but still oriented toward the supergrid. This is a Modernist grid system, and in some ways is just a higher density version of places like Irvine, California. Osaka and Taipei are a bit more like Lower Manhattan, where it looks like an organic pattern was modernized (and in some places entirely demolished) to make way for a more regular, modern city. Beijing is unique, in that it’s grid is very much a show of power, demonstrated initially by the godlike emperor, and now has been co-opted to a degree as a symbol of the power of the state.

Three cities showed gridiron plans. Of these, Delhi and Hong Kong can be explained as colonial intervention. Nagoya, on the other hand, is laid out in its grid as a form of cosmic or religious significance.

On to Africa.

Africa:

But just barely.

Africa was the only continent without a landslide winner, with 25 of the top 50 cities being loose grids. However, this can largely be explained by the differences between North and Sub-Saharan Africa.

All of the loose grid cities are located south of the Sahara Desert. It may be that these cities were built on African foundations, but were regularized through European colonialism.

Seventeen of the remaining cities feature an organic pattern at their center. Although a handful of these are in West Africa, and one in Madagascar, most are in North Africa. This dense organic pattern is the Medina, the old quarter of the Islamic world. These narrow, winding, and often dead-end streets are the result of Muslim teachings related to the family and privacy. Even in these cases, however, there is often a more formalized colonial quarter outside of the center, as is very well illustrated at Algiers.

The last eight cities all have gridiron plans. Of these, half of them are in South Africa, arguably the part of Africa most heavily colonized by Europeans. No wonder it looks the most like the US.

I decided not to do Australia, because they only have 16 cities with over 100,000 people so it wouldn’t really be on the same scale as everything else I’ve been looking at.

Looking at the grid of a city can tell you a lot about its history, and looking at the grids of many cities can tell you about a larger culture. I think many people in the Americas value the organic cities we find in Europe, which is one of the reasons so many of us with means choose to visit them. But while we could see that sort of urbanism at home, our governmental and development structures don’t support it. But who knows; as governments and cultures evolve, and given enough time to properly age and grow, cities may be able to overcome the power structure of the grid for a more free and natural organic pattern.

May 2015 Update: Oceania

As I said above, Australia only has 16 cities with over 100,000 people, so I had passed over it before. But this post ended up on Reddit and several commentators mentioned that, even if Australia didn’t have enough for a larger sample, I should have expanded it to Oceania.

The question becomes how one defines Oceania. Generally, it is made up of the small island nations of the Pacific. It often (but not always) includes Australia and New Zealand, and less regularly includes Indonesia, Malaysia, and Singapore. When I looked up lists of population figures for Oceania, I could only find lists for Australia, Indonesia, New Zealand, and Papua New Guinea. Since Indonesia could be Oceanic or not, I decided to take a look at both options, just to be sure.

So, with Indonesia:

Of the top 50 cities in Oceania with Indonesia included, 33 of them are organic. Of those 33, every single one of them is in Indonesia. Since none of them are in any of the other countries, and since Indonesia is not by all definitions considered a part of Oceania, I thought I’d take take them out and see what we had. With only the 25 cities from the other three nations with over 100,000 people, it was barely enough for a good sample, but here’s what you get:

Of the 25 cities, 13 have loose grids. In a lot of cases, some of these cities might have a very small gridiron area that quickly has to adapt to steeper topography, as is the case in Brisbane and many of the cities in New Zealand. Other cities, like Sydney, are almost more of a hodgepodge of grid types from neighborhood to neighborhood. Eight cities had gridiron plans, although they were often limited to their downtowns and fell apart into one of the less regimented systems further out. Two cities in Australia, Gold Coast and Sunshine Coast, are unusual in that they are essentially just very very large suburbs. Port Moresby in Papua New Guinea has an organic plan, and Canberra is well known for it’s modern interpretation of the Baroque radial grid plan.