ATLANTA — Could this traffic-clogged Southern city, long derided as the epitome of suburban sprawl, really be discovering its walkable, bike-friendly, density-embracing, streetcar-riding, human-scale soul?

The answer is evident in the outpouring of affection that residents here have showered on the Atlanta BeltLine, which aims to convert 22 miles of mostly disused railway beds circling the city’s urban core into a biking and pedestrian loop, a new streetcar line, and a staggeringly ambitious engine of urban revitalization.

Even though just a small fraction of the loop trail has been completed, Atlantans, in one of the purer expressions of America’s newly rekindled romance with city life, have already passionately embraced the project. And like any budding romance, it is full of high hopes — for an Atlanta that is more racially integrated, less congested and, in a change refreshing to many here, more focused on improving the lives of residents rather than just projecting a glittering New South image to the rest of the world.

It’s not just Atlantans who see something that is potentially transformative.

“It’s the most important rail-transit project that’s been proposed in the country, possibly in the world,” said Christopher B. Leinberger of the George Washington University School of Business, who follows urban redesign projects and has for years called Atlanta “the poster child of sprawl.”