As urban areas develop, each city forms a unique structural logic. With this structure usually conceived on an ad-hoc basis, political terms such as “metropolitan area” and “neighborhood” are not always useful when analyzing and comparing the performance of cities. In a quest for new analytical tools, Robin Renner has devised an anatomically-based classification system in his new book Urban Being: Anatomy & Identity of the City. Through a thoughtful investigation of existing urban areas from around the globe using satellite images and personal experiences, Urban Being offers an insight into how transportation networks and streetscapes can be best organized to promote a healthy metropolitan environment.
Renner’s analysis ranges from macro-regions that can even cross country borders to the defined spaces between arterial roads in cities, which he calls "urban cells." As the neighborhoods and units in which inhabitants reside, urban cells are important when examining the identity and efficiency of a city. They are defined by both their physical properties and the actions that take place inside of them. Below is a small sample of how Renner analyzes urban cells from the book.
The form of an urban cell depends on two main factors: topography and transportation. Topographical conditions such as the mountains of Rio De Janeiro and canals of Amsterdam have created cells of varying densities. In Los Angeles for example, the network of highways and roads—referred to as main arteries—grids the city in such a way that compresses the center and expands in the periphery to form large residential cells. These forms, in turn, have an effect on the types of buildings and functions that are typically hosted in these cells.
The smallest typology of urban cells is the block cell, which is a singular block surrounded by main traffic arteries. Due to high automobile and pedestrian traffic, high-rise office buildings typically concentrate here. The bustling nature of these cells discourages the development of quieter programs such as living and dining. Examples of block cell sub centers are the financial districts in Los Angeles, Melbourne, Taipei, and Shanghai.
A linear cell is often created when a main artery is divided into two one-way streets, causing more narrow and pedestrian-friendly avenues. Along with factors such as slow automobile traffic and strong public transportation, linear cells are important commercial hubs. Copacabana is an example of a linear cell that has long been utilized as a destination for shopping in Rio de Janeiro.
The largest cell in the nucleus is the central cell. This cell is often the origin of the city and in the physical center. Central cells have the highest density of pedestrian traffic, therefore housing a large concentration of stores and restaurants. Since these cells have often divested of automobile infrastructure, public transportation plays an important role in the movement of people towards the center. Cities such as Stuttgart and Munich have strong central cells that connect commerce and pedestrians.
The way in which a cell is used is can also determine its size and traffic pattern. Cell functions can range from offering only the basic conditions for living to including more diverse uses such as parks and commerce. Cells with a priority on pedestrian accessibility typically feature residential housing, and cells with heavy automobile traffic favor business and industry.
Successful residential cells feature slow interior traffic that allows for pedestrian-focused streets. Trees, centrally located parks, supermarkets, and schools increase the quality of life for residents in this cell. Although the residential cell should provide a quiet living area, it should not be completely disconnected from the rest of the urban nucleus. This connection is provided primarily through the arterial main roads and the public transportation centers found along them. Renner defines the ideal size for residential cells to be between 400 meters and 800 meters based on examples such as Polanco in Mexico City and Providencia in Santiago.
Due to their access to highways, railroads, or rivers, large central cells are conducive to industry. The growth of a city has been historically tied to the success of its industrial exports and is still a vital factor in its strength. According to Renner, public transportation should be introduced into industrial cells so that workers can have a shortened commute and be less reliant on cars. Edmonton’s oil and gas enterprise is an example of an industrial cell that formed through its proximity to train tracks.