Criticism of modernistic urban planning and its failures tends to epitomize Le Corbusier as the main culprit behind the change in planning approach during the 20th century. Some may suggest that without Corbusier our urban planning would remain humanistic and rational like at has been during most of human history. While Corbusier definitely deserves an honorary place among the people who destroyed the profession of urban planning and created inhuman habitats, he was far from being alone, and was working in the zeitgeist of his time when many other planners envisaged a slew of anti-urban plans.

One of the modernistic concepts which is (unfortunately) still very much alive is the Neighborhood Unit. This concept was summarized by Clarence Perry in 1929 for New York Regional Survey and is the main subject of this post. Below is the most recognized diagram that is associated with Perry’s work. You may note that Perry surrounded his ideal neighborhood with highways and on further inspection you may also note that he avoided making any direct links from one neighborhood street to another neighborhood across the highway, thus making sure its neighborhood remains in its own limited world.

Neighborhood Unit Diagram. “New York Regional Survey, Vol 7” by Source. Licensed under Fair use via Wikipedia.
Neighborhood Unit Diagram

Perry advocated for planning of an autonomous unit centered around an elementary school with just a little bit of everyday needs in it. When reading his seminal text a few points pop up, that are unfortunately still very prevalent in current planning practices almost a hundred years later. For one, Perry’s meticulous analysis the elementary school (from page 46) carefully examines the number of children in an average household and goes on to use this demographic information as if it was written in stone. Well, as it happens average households in New York today are quite different than they were a hundred years ago (they are much smaller with much fewer families having three children or more) and will probably be very different in another hundred years. The same goes for his analysis of shopping needs (from page 76) which again assumes that society is static. Perry goes into enormous details on the specific shops that are needed inside a neighborhood unit (including a millinery, which is a fancy word for a hat making shop) versus those that should only be found downtown.

The basic assumption is that everything is static – demographics (family size) do not change and society needs at large do not change (schools, churches and so forth). Furthermore, as far as urban development goes, Perry assumes that in the future everything of importance will be concentrated in the downtown and no significant urban changes will occur in terms of metropolitan development and land use dispersal. To some degree, assumptions of an unchanging future are the backbone of all modernistic urban planning. After analyzing people’s needs Perry proceeds towards the street network he thought would liberate people. The text embraces full automobility as inevitable and predicts that in the future everyone will have an automobile and every trip outside of the neighborhood unit will be done by one. It assumes only two kinds of streets – local streets and fast highways. There is no place for main streets (major commercial streets) in Perry’s world. Against this unrealistic background Perry tried to address pedestrian needs and made his neighborhoods completely disconnected from each other and from the city that they were added to.

The diagram below shows how Perry viewed the classic American open-ended grid that is at the base of all the decent urbanism that still remains in the US. In his view the grid led to nowhere in particular, while his closed street scheme leads to “place where people want to go”. In practice the grid leads to a myriad of destinations open to change and growth, while a closed and disconnected street network leads to a place that’s quite resistible to change.

Where do you want to go today?
The neighborhood unit - Perry-42

The prevalence of the Neighborhood Unit concept in urban planning and current state of debate on its merits and downsides is neatly articulated in a recently published academic paper in the Journal of Urbanism by Michael Mehaffy, Sergio Porta and Ombretta Romice. The paper is titled: “The “neighborhood unit” on trial: a case study in the impacts of urban morphology”. Mehaffy et al. show that even advocates that work on urban planning reform such as the American New Urbanism tend to view the Neighborhood Unit in a positive way. The paper goes on to show how Perry tried to separate between slow pedestrians and fast moving vehicles so as to accomodate vehicular traffic to the largest degree possible. The authors dig deep and discuss how Neighborhood Unit plans may lead to increased segregation and significantly hamper public transit:

By not centering neighborhoods on arterials, the Perry model and its variants create a fragmented transit service area that cannot be serviced cost-effectively. According to such critics, this failure has a significant impact on the viability of a public transit system, and on the resulting ability to reduce carbon emissions from urban transportation.

In contrast to the dysfunctional Neighborhood Unit a few examples of real city development with emphasis on well connected urban fabric are given: London, Barcelona and my personal favorite – Portland, Oregon.

Perry’s Neighborhood Unit concept did not wreak havoc only in the USA, but spread across the globe. Israel, which was established during the modernistic golden age (1948) embraced the Neighborhood Unit concept with zeal and now has many municipalities made only of Neighborhood units with no real city parts whatsoever. One example for such a place is the port city of Ashdod (established 1956) which consists of a large port and industrial area to its north and 17 Neighborhood Units to the south. The city has about 250,000 people in it, but instead of utilizing this congregation of people it is actually made up of 17 villages of 10,000-20,000 people, each with its own slowly decaying low-level commerce. Below is Ashdod’s map with its disconnected neighborhoods.

Ashdod is now trying to take one of its arterial roads and turn it into a real urban street, connecting its disjointed neighborhoods (you can read more about it here) with an ambitious plan that tackles street network changes, land use changes, commercial development and public transit. Whether such a change is feasible is open to debate.

In conclusion, planners need to be aware of the Neighborhood Unit’s major shortcomings and should resist the urge to plan a closed and segregated ideal and never-changing urban habitats. After all, those places may be much worse than open-ended places that are open to change.