The turning radius of a team of four oxen pulling a four-wheel cart determined the width of the streets in Salt Lake City. (Image source: Wikipedia)
I´ve been reading the article by Fanis Grammenos at Planetizen.com, which I´ve found highly interesting, specially for me that have been living in Buenos Aires´ grid for so many years.
He writes about the pros and cons of the grid, first of all, he shows two charts of developable land compared to right of way (ROW) and size of block for some cities in USA.
Then, he gives us examples of critics from urbanists, beginning from those who defend urban fractal morphology. At this point, I should make a separate note. As an example ¨in between¨, Buenos Aires is a strict grid but seen in 3D or seen by a pedestrian, it is highly fractal; I wrote many articles about it. So, articulations and scaling are not lost.
A sampling of 3 simple grids and their corresponding percentage of land used for ROWs.
¨Olmstead in the 1800s abandoned orthogonal planning and introduced curvilinear streets that were to become the model for innumerable subdivisions. Camillo Sitte portrays the grid as unimaginative and unworthy of consideration for new towns. Raymond Unwin in his writings and works rejects the simple, open grid, succeeds in ushering the cul-de-sac through the British parliament and lays out plans free of the rigidity and repetitiveness of the simple grid.
As contemporary theory embraces the city as an organism that obeys fractal laws (seen in the works of Alexander, Salingaros, Mehaffy, Mashall and Salat), more fundamental weaknesses of the uniform grid emerged. For example we read that: “Making a line straight, or regularizing a street, as 19th century urbanism has often done, eliminated intermediary scales and hence the possibility of geometric interaction and coupling of smaller scales. In other words it killed life. For thousands of years, historical cities avoided straight lines, creating multiply connected rich structures by way of slight discontinuities in relation to straight lines.”(Salat)¨
Then, Grammenos explains that some blocks length are the product of the need for a team of four oxen pulling a cart to turn around within the street; and of course, a modern adaptation is needed.
We cannot copy good examples from another countries, to prioritize pedestrians; what is good for Middle East, is not good for fast avenues in California, right?
Finally, he proposes a middle-term solution, which I like very much, it´s a block with partitions as needed for vehicles and pedestrians.
Breaking the convenient, but outdated, uniformity of the 18th and 19th Century American grids would be a first step in recovering the land efficiency mandated by current ecological and economic imperatives. Pointing in that direction, Savannah’s composite, cellular grid includes variable size streets and blocks for private, civic and religious functions. A second step would be to include block sizes that can accommodate building types and sizes unknown in the 1800s, again defying block uniformity. A third step would be to adapt its streets for the now universal motorized mobility, of cars, buses, trucks, trams and motorcycles, that is radically different from when oxen, equine and legs shared the transport of goods and people.
In summary, examining the simple grids in this set serves as an introduction to optimizing land use, people circulation and the movement of goods. The resulting challenge is to use these insights to develop patterns that accommodate contemporary urban land economics, transportation, environmental priorities and citizen aspirations as these patterns may have done in their time.
Read the article in full: