We recently linked to a Times article describing the French proposal to make Paris a 100-mile metropolis, stretching along the Seine river valley to the English Channel at Le Havre.
While the concept can stir the imagination, urbanists should approach it with a lot of professional scepticism. There are practical problems with the idea, but allow me to dwell first on the geometric problem, which is fairly abstract.
While towns often form along existing routes or at crossroads, beginning as linear or radial strip settlements, by the time they become cities they are tangled knots of radial and concentric systems. Large cities tend to be simple blobs in shape, unless deformed by severe topographic constraints like Mumbai or San Francisco. Even the New York agglomeration has overcome the twisting of the Hudson to become a blob centred on Manhattan.
A city cannot be stretched out along a line for the same reason that a soap bubble cannot be a long, thin rod. It is a grossly inefficient form to contain the forces pushing and pulling within the urban fabric. (True physicists will realise this is an inaccurate analogy, but they will bear with us mere urbanists.)
A linear city experiences either chronic congestion or massive duplication of infrastructure along its spine, as Mumbai's rail lines and the San Francisco Bay area's freeways demonstrate. The populations of different suburbs are sorely isolated from each other by the extreme distances, reducing the natural flow of goods and labour across the city, making an inefficient spatial economy.
Like a long soap bubble, a city conceived along a line will tend to 'burst' into two or more smaller blobbish bubbles again. In the case of the 100-mile metropole, we would really only see an expansion of three bubbles: Paris, Rouen and Le Havre. Only very specific activities not dependent on the intrinsic efficiencies of urban locations will line the highways between the three. These are typically light industry requiring very low overheads and premium residential development like retirement villages and country homes.
The 100-mile metropole is thus merely a rhetorical device, not a viable proposition for the metropolitan form of Paris. It is merely to galvanise support for the idea that Paris requires a major seaport. But how should we evaluate even that proposition?
We should look at the rest of the rhetoric. The proposal is introduced with the following phrases (in French here):
"The future of greater Paris and of France turns on bringing together the sea and the capital. History shows us: no metropolis can truly attain a global scale without a maritime dimension, and the global cities of yesterday and of tomorrow move towards their ports. … We must urgently make Paris … the seaport and natural capital of Western Europe."
What's wrong here, apart from typical Gallic hubris? Firstly, history shows us less than we think in the information age. Many cities attain global status by developing superior knowledge economies, and many port cities remain as mere entrepots for their regions. The global cities of Europe are the likes of London, Paris, Milan; its busiest ports are the smaller cities of Rotterdam, Hamburg and Antwerp.
Secondly, the future of France does not depend on the global status of its capital; this is a Parisian's fantasy. France has five other major seaports and several major cities outside Paris all worthy of investment. Of these, Marseilles is far better located for the busy shipping lanes through the Suez canal, and Nantes or Bordeaux better pointed towards West Africa and the Americas. Reviving France's industrial power requires a concerted strategy for all of these centres; overinvesting in Paris would be to their detriment.
The industrial rhetoric clouds some of the real politics behind the proposals. Jean-Claude Hazera, editor of the French financial paper Les Echos, makes a number of excellent points (in French here).
The mayor of Le Havre "underlines the importance of ports, invoking the fact that 85% of global merchandise passes by sea. Yet the landmark project that has really galvanised [Normandy's politicians] is the transport line … for passengers! … The Paris seaport is perhaps nothing other than a big TGV lobby."
Considering the merits of the industrial argument, Hazera proposes that "the capital is very well connected to the sea by Antwerp … and soon the Seine-Nord canal. Le Havre can develop, even without any connection to Paris, as the premier large port on the Channel, sending off containers towards London or Duisburg [Dusseldorf] in the Ruhr." The fortunes of Paris and Le Havre are far less interdependent than the 100-mile metropole suggests.
The best argument Hazera sees is that Paris build a manufacturing and processing economy behind Le Havre and Rouen, noting that Paris is no further from these ports than Beijing is from its ports in Tianjin. But this requires inverting the spatial structure of the Paris region. "The logistic capacities of Île-de-France, highly centred on the east and southeast (Melun, Rungis) must be tipped toward the west."
To do this requires land for redevelopment, which is not forthcoming. Mayors all along the river near Paris refuse to cede their terrain, and downstream of Rouen, "the ecologists dream of classing every loop of the Seine as natural reserve."
At this point the grand projet is little more than a troublesome and expensive industrial development plan for northern France. The debates have drifted far from the 100-mile metropole lovingly depicted by architect Antoine Grumbach in last year's competition.
Planning the expansion of a city is less about formal invention than we would like to believe, and more about wrestling prosaically with the logic of the regional economy. Little of the logic behind the 100-mile metropole seems arresting enough to radically reshape the city of Paris.