Dense urban centers are good; sprawling suburbs are bad. Put in the simplest terms, that's what the conventional environmental wisdom tells us. But sometimes spreading out a little is just what a big city needs.In already massive metropolises like Mexico City and Istanbul, the built area sprawls over a vast acreage, while much commercial and economic activity still takes place in the center, forcing residents to commute long distances on a daily basis. Istanbul has expanded 57 percent in just the last 30 years, while the Distrito Federal, or Mexico City proper, now holds less than half the population of the greater metropolitan area.
Bringing 'Cityness' to Outlying Communities
"Mexico City is now taking place outside the city," architect and professor Jose Castillo told the participants at the ninth Urban Age conference, held this past week in Istanbul, before posing the question: "Is mobility about bringing people to the city, or about bringing cityness to these communities?"
New plans for both London and Paris hope to address similar problems by enhancing and linking emerging areas of urban concentration to create "polycentric" cities that minimize transit needs (and thus environmental impact). Anticipating an influx of 800,000 new people between 2001 and 2016, London hopes to contain that growth on already developed land within its existing greenbelt by increasing density around a network of public-transportation hubs, said Richard Rogers, the chairman of the London-based architecture firm Rogers Stirk Harbour + Partners.
'Repairing the Breaks in the Urban Fabric'
Likewise, the French capital is making its development plans in line with the motto "build Paris on Paris," Rogers said. "Existing transit networks are often radial, so you always have to go through the center," he added, noting that by connecting outlying neighborhoods with ring routes, you "create value by repairing the breaks in the urban fabric."
Hafencity will be connected to the rest of Hamburg through pedestrian and cycling routes, as well as metro lines. Image via Hafencity Hamburg.
Retrofitting and integrating deteriorating, underused parts of a city -- without displacing the often poor people who live there -- is a crucial part of such a strategy. In London, the 2012 Olympics site is being created in a former industrial area with high levels of unemployment that has been cut off from the rest of the city by freeways. In an attempt to rebuild the area for the Games and beyond, 30 bridges and underpasses to the surrounding neighborhoods are being planned to keep the new development from "becoming an island," according to Olympics executive Andrew Altman.
Integrating Anacostia and Hafencity
In Washington, D.C., efforts to restore the neglected Anacostia waterfront seek to bring the impoverished area onto the regular city map, while Mexico City is introducing a bus rapid transit line to integrate informal settlements on the outskirts, and the Hafencity plan for Hamburg's obsolete harbor is connecting the old waterfront to the rest of the city through new metro lines and pedestrian bridges.
"When we assume that a district is decaying, it hides the fact that it also holds life and resources," said Richard Sennett, a sociology professor at the London School of Economics. "Decay is often presented as a progressive disease like cancer that requires drastic surgery. But the preference we should always have as urbanists is to take what's there as reparable, which assumes that the people who live there are capable of regenerating these places, not that they themselves are decayed and need to be replaced."
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