Editor's note: Ryan Gravel is a senior urban designer at Perkins+Will. His master's thesis was the original vision for the ambitious Atlanta BeltLine urban renewal project.
Atlanta (CNN) -- It may seem ironic that one of the most sustainable city infrastructure projects underway in the United States is taking shape in a metropolitan region known best for its traffic congestion and expansive urban sprawl.
Or perhaps it should be expected here, where, consciously or not, we are beginning to reconcile the physical structure of highways and arterial roads on which we have prospered for the last 60 years with a dramatically changing marketplace that has rendered that structure newly less desirable.
In either case, it is remarkable that in a region many view as the poster-child for urban sprawl, we also find the Atlanta BeltLine, a uniquely innovative, sustainable and ambitious idea that has begun to address not only the physical challenges of sprawl, but also to change Atlanta's cultural expectations for itself and for its future.
And for regions of the world as culturally different as China and The Netherlands, where one can find evidence of the same early steps toward urban sprawl that America took six decades ago, Atlanta's grasp for more sustainable strategies should serve as fair warning.
In college, I spent a year abroad in Paris and almost every day I would walk under an abandoned railroad viaduct on my way to the grocery store or laudromat. When I returned a few years later, the viaduct had been transformed.
At street level its large brick vaults were filled with arts-related studios and businesses, reinvented as the Viaduc des Arts. And along the railroad up top there was the Promenade Plantee, a linear garden walk with a third-story vantage point that changes the way you see Paris and how people might think about obsolete urban infrastructure and public space.
Later in graduate school, I envisioned a much larger transformation for my own hometown. The Atlanta BeltLine began its current reincarnation as my thesis project on public transit, economic development and community revitalization.
The proposal repurposes a loop of mostly abandoned railroad tracks encircling downtown into a sustainable new transportation corridor and a signature public meeting ground comprised of a linear park with an electric tramway and multi-use trails. It reinvigorates 45 diverse neighborhoods along the way, organizes adjacent abandoned industrial land for transit-oriented development, expands transit service within the urban core, and connects various parts of an emerging regional trail system.
But while this physical transformation of underutilized infrastructure is a relevant precedent for other cities -- the Promenade Plantee is itself a prototype for the much larger, BeltLine-scaled Petite Ceinture that encircles the historic heart of Paris -- that may not be its most compelling story. In a world that faces daunting challenges for sustainable urban development and increasingly polarized politics, perhaps a more important lesson is the project's role as a catalyst for cultural change.
Starting in 2001 and over the next three years, with infectious optimism and a lot of hard work, the citizens of Atlanta bought into a compelling grassroots vision for the Atlanta BeltLine and made it their own, creating a powerful informal alliance between neighborhood groups, developers and nonprofit organizations who found themselves in the unlikely position of advocating for the same set of ideas.
This broad support then empowered the city's political and business leadership to endorse the project and sparked an expansion of the project's vision, including over 1,000 acres of new parks, the largest affordable-housing initiative in the city's history and perhaps the longest and most unique arboretum in the country.
With every expansion of its vision, the physical project reinforces changing cultural preferences about the built environment, demonstrating local sustainable growth strategies that can be applied to other parts of the region, and over time, make comprehensive changes more politically palatable. In this way, the Atlanta BeltLine not only profoundly changes the physical city, it changes the way we think about Atlanta -- what is possible, and what our cultural expectations are for the places that we live.
This kind of change is critical to the region's economic success -- to any region struggling to reinvent itself so that it can thrive in the global marketplace. Because while these new perspectives contrast sharply with previous generations who built our sprawling roadway network, they mirror national shifts in preferences about the built environment driven largely by a general disenchantment with car-dependent lifestyles and an increasing desire for cultural authenticity in the places that we live and work.
Successful cities have always been places where people want to be, and once again technology and changing generational preferences are redefining that kind of place, this time leading us back toward social environments with mixed-use districts, strong cultural resources, greater mobility and a more robust public realm. Communities that recognize and take advantage of these changes first will be best positioned to succeed in a more competitive future.
So whether they look to district-scaled projects like the South Bronx Greenway in New York or Seoul's Cheonggyecheon, or to city scaled projects like the Petite Ceinture or Madrid's Calle-30, or to complex regional proposals like those for the Los Angeles River, cities can find innovative, non-partisan public works projects that not only begin the physical transformation required to attract future residents and jobs, but also catalyze a cultural shift in thinking about what kinds of policies and infrastructure we should be investing in. This cultural shift will mean far more for global sustainability than any physical project ever could.
The opinions expressed in this commentary are solely those of Ryan Gravel.