The problem of city making today does not so much concern making new ones as it does transforming those that already exist-especially suburbs-and edge-city developments. What can the United States learn from French President Nicolas Sarkozy and his goal to remake Paris?

President Barack Obama has called for investment in infrastructure, education, and renewable energy initiatives to secure a future in which the United States remains competitive in the 21st century. Though billions of dollars have been allotted to infrastructure as part of the stimulus package, it is not clear how these investments will strategically affect the development of America’s ever-expanding cities. Can investments in the public infrastructure and the public realm yield synergistic results that generate sustained economic drivers while enhancing the quality of life and the environment?

Important questions loom concerning the role of public leadership in rethinking the metropolis, especially as leaders face pressing economic challenges. Despite the state of the economy, French President Nicholas Sarkozy has recently invested considerable political and public capital in finding a way to comprehensively transform Paris and its suburbs into a more sustainable and effective urban form.

His awareness of the importance of metropolitan affairs was heightened when, as French interior minister, he witnessed the 2005 suburban riots in La Courneuv and came to recognize the social and political consequences of inaction. In response, Sarkozy now is leveraging the French presidency’s traditional prerogative to undertake a “grand project”—in this case, tackling the seemingly intractable problem of redesigning the Paris suburbs as part of a larger metropolitan vision.

Whereas former Prime Minister Georges Pompidou and former President Francois Mitterrand built cultural monuments in the city’s center, Sarkozy has chosen suburban Paris and the larger metropolitan area for his grand project. In September 2007, he established a commission to select ten architecture firms to lead multidisciplinary teams. Engineers, geographers, social scientists, and even philosophers collaborated on Sarkozy’s challenge: to create bold visions for making Paris a model post–Kyoto Protocol metropolis of the 21st century to drive economic activity and innovation while enhancing the quality of life of residents.

The project is not focused on the picture-postcard views of Paris and its broad tree-lined avenues. While Paris represents an urban ideal in the history of city making, this urban model does not extend outside Le Périphérique—the 20-mile (33-km) arterial roadway that circumscribes Paris’s core. Yet, more than three-quarters of metropolitan Paris’s 8 million inhabitants reside in its suburbs, which have been the site of social unrest and riots. High unemployment, poor access to transit, and poorly designed housing developments are but a few of the challenges plaguing Paris’s poorer immigrant suburbs. In some places, the large swaths of land required to support the highway and rail networks servicing the city and its surroundings have carved up the suburbs into fragmented and isolated districts, limiting links between suburbs and between the suburbs and the city. The suburban architecture and public spaces are less than remarkable. And, as the girth of the Paris metropolis expands, farmland and landscape are consumed, damaging the ecology and tarnishing the landscape.

These problems have a familiar ring in the United States. The suburban development pattern of post– World War II America has been exported around the world, prompting unsustainable development and building practices. The problem of city making today does not so much concern making new ones as it does transforming those that already exist—especially suburbs—and edge-city developments. The suburban metropolis is relatively young.

Coherent strategies have yet to be developed for transforming metropolitan agglomerations into urban configurations that are ecologically, economically, and socially sustainable, as well as environments that are memorable and provide architectural delight. Therein lies the potential of Sarkozy’s undertaking— that it serve to advance this discussion while providing a repository of solutions.

The results of the design initiative were introduced to the public in March 2009, offering an illuminating analysis of the Paris metropolis and associated problems. The plans put forth by the ten teams of designers at firms such as Jean Nouvel, Studio 09, Antoine Grumbach, and Studio LIN tackle such issues as the often-inefficient infrastructure systems and development patterns found in Parisian suburbs that burden limited community and government financial resources.

Since the architects’ presentations a year ago, Sarkozy has announced a major new $50 billion infrastructure initiative supporting complementary proposals for improving and extending the subway network between the suburbs and other destinations like airports. In December, the French National Assembly approved a bill, proposed by development minister Christian Blanc, outlining a Greater Paris Metro line expansion. The proposed 80-mile (13-km) loop would connect airports north and south of the city with business centers and suburbs. The $32 billion project is still pending Senate approval, but is proposed to open in 2017. Sarkozy also established L’Atelier International du Grand Paris, a public interest group made of the ten teams, to more formally establish objectives for transforming Greater Paris.

In the original proposals submitted, a number of the teams focused on strategies for densifying and intensifying underused areas by layering new buildings, programs, and infrastructure onto the existing suburbs. Strategically introducing new building types or hybrids— buildings that combine different uses and building typologies—are effective tools in establishing new, more efficient development patterns. In particular, some hybrid types that combine landscape and infrastructure can be effective in healing the scars of poorly conceived highway and rail projects that separate communities from each other or from the landscape.

Other teams proposed improving the integration of infrastructure systems as a way of connecting inaccessible metropolitan districts or simply reducing transit time between metropolitan destinations. Overlaying new transit routes as part of an expanded multimodal system not only can create a more efficient and effective transportation network, but also can make underused districts more valuable.

Combating the negative effects of the sprawling metropolises on local ecologies was a key driver in many of the design proposals, which used inventive strategies for integrating nature into the city. For instance, the river Seine and its valley could act as a revitalized armature for urban development models that are ecologically sensitive. Urban development could be concentrated in existing nodes and corridors, while farms and forests would be preserved and restored as part of protected green precincts. As development pressures increase, solutions for intensifying existing built areas would take hold. Nature is not limited to green zones, however. A number of proposals illustrate strategies for repopulating the metropolis with farms and forests, generating recreational opportunities while pumping oxygen into the atmosphere.

The model of a city consisting of a center supported by satellite communities is consistently challenged in most of the design initiative schemes. The postindustrial metropolis operates as a polycentric/ multinodal conglomeration. While this current form and structure may not be ideal, recognizing this reality permits the engagement of new strategies, including the coordinated infusion of infrastructural, urban, and architectural interventions to strengthen connections between dispersed nodes. This would allow the metropolis to evolve into a meaningfully interconnected and layered network of nodes, each intensified with new uses and amenities. Success would be dependent in part on the knitting together of new and existing infrastructure systems.

Sir Richard Rogers, principal of London-based Rogers Stirk Harbour & Partners, proposed ten guiding principles for metropolitan Paris, addressing its governance, economy, transportation network, and environmental footprint. The design strategy focuses on creating a new metropolitan armature that helps bridge the physical barriers of the city and create a new compact polycentric metropolitan city by strengthening transportation interchanges.

Transforming existing infrastructure systems into a new green armature would help the city overcome existing barriers separating neighborhoods. The plan, where viable, would cover existing large swaths of rail lines segmenting the city. New multilayered, multipurpose parks would bridge the rail lines and help restitch the city’s fabric, while water purification systems, renewable energy sources, recycling centers, and other amenities would be provided.

The proposal by Paris-based Antoine Grumbach and Associates would build on Napoleon Bonaparte’s 1802 concept of having Paris–Rouen–Le Havre function as a single city with the Seine as its main road. This proposal considers city making as a region-scaled enterprise. By overlaying a lattice-like system of infrastructure—high-speed trains, public transportation, road networks, open space, and even art installations—onto the existing cities and villages in the Seine’s broad valley, the plan interweaves nature and urbanity as part of a higher-order metropolitan network. This strategy would provide greater accessibility to regional cities and increase clarity regarding the metropolis’s form and order. However, the question arises whether, in extending the reach of the metropolis, this strategy would perpetuate sprawl, or instead would preconfigure the metropolitan form and limit its destructive tendencies.

Paris-based Pritzker Prize–winning architect Jean Nouvel recognizes that the complexity of the Sarkozy’s project is so big that one can “only pick a few points of intervention.” One of Nouvel’s tactics would be to transform the nondescript towers, slabs, and under-used public spaces of the modernists’ failed housing developments into a varied collection of hybrid building types. By selectively demolishing parts of buildings, altering unit layouts, redefining entries, and adding building skins, the Nouvel plan would create the possibility of a new identity for residents. He also proposes rethinking the role of the surrounding landscape, its forest, and its farms. Clearly defined green zones would be brought into the city, to the front door of residences and neighborhoods, offering community farming and recreational opportunities. Renderings of crystalline towers, immersed in the transformed fabric of housing estates and reconstituted landscapes, convey a bold future for the metropolis.

Italian architects Bernardo Secchi and Paola Vigano of the Studio 09 team think of the city as a kind of “porous sponge” and center their attention on a system of waterways. They propose transforming the metropolis according to an understanding of the ecology of the Seine and its supporting tributaries, as well as the network of canals and harbors. Anticipating the impact of global warming on the metropolitan topography, their plans would layer future developments and systems to give Paris a new “spatial structure without destroying the city.”

The proposal of Finn Geipel of the Berlin-based LIN team calls for a full range of architectural and urban transformations. It recognizes that change will take time. Time-lapse images show how neighborhoods and districts could change over time as part of a compact and multipolar metropolis that “engages urban qualities and natural wealth.”

Winny Mass and the Dutch architecture firm MVRDV call for a Paris Plus agenda, promoting “more ambition, more density, more efficiency, more ecology, and more compactness.” MVRDV proposes use of its software and web tool, the “city calculator”—developed in collaboration with the Why Factory, a think tank at the Delft University of Technology in Delft, the Netherlands—to support sustainable planning. The tool uses qualitative and quantitative parameters to develop design proposals that can evaluate the city’s potential behavior and performance in comparison with other cities.

Ahead is the more challenging problem of implementing the full range of ideas presented in these proposals as vision meets reality, in particular navigating the complicated decision-making processes governing the Paris metropolis. As an example, the proposed Metro expansion was not without opposition in the National Assembly, passing on a vote of 299–216. The opposition asserts that too much would be spent on a quick fix to a much larger and complex problem.

At this critical time, what can be done in the way of rethinking cities, suburbs, and metropolises more synergistically? While the American Recovery and Reinvestment Act recently provided California with $2.3 billion in funding to build a high-speed, intercity rail line from Anaheim to San Francisco, it pales in comparison with China’s expansive infrastructure initiatives. China’s new nationwide high-speed rail network is the second-largest public works program in history behind the Eisenhower interstate highway system. More important, though, such massive initiatives need to be coordinated as part of larger integrated efforts to view the metropolis as a key building block in regenerating a renewed economy.