Inspired by his studies in Paris, Ryan Gravel wrote his master's thesis at the Georgia Institute of Technology on his idea of converting Atlanta's abandoned 22-mile-long freight-rail corridor, which encircles the city's urban core, into a "belt line" that would reconnect the city's neighborhoods. After graduation, the idea lingered. Gravel later started Friends of the BeltLine, a non-profit that helped win support to push the project forward.

GRAVEL

Gravel's thesis has evolved into the $2.8-billion Atlanta BeltLine project, now under construction. The massive undertaking—one of the largest of its kind in the world—will incorporate 22 miles of transit, 33 miles of trails that connect 40 city parks, an arboretum and 1,100 acres of brownfield redevelopment as well as the city's largest-ever affordable housing initiative. In 2011, city officials opened five new BeltLine parks, the project's first allotment of an estimated 1,300 acres of new parks and green space.

Now a senior urban designer with Perkins+Will, which is handling the corridor design, Gravel remains rooted in the community and even moved his family to a local neighborhood.

Gravel says the BeltLine is about transforming Atlanta and giving the city a tool to compete. "The way [cities] compete is by making themselves into places where people really want to live," he says.

Following that logic, he insists the BeltLine's most important design ideas don't belong to him, but to local residents.

"The biggest thing is [Gravel's] continued insistence and involvement in making sure this grassroots project remains centered in the community," says Valarie Wilson, executive director of the Atlanta BeltLine Partnership.

"He gave Atlanta a great idea and a great vision," Wilson says.