The Atlanta BeltLine, dubbed, the country’s “most ambitious” or “best” smart growth project is, obviously, a big project. It involves re-purposing a 22-mile rail corridor to include new forms of public transit (streetcars or light rail connected to MARTA at a number of locations), trails for walking and bicycling, and a number of parks, all around the center of Atlanta. The city is putting $2.8 billion (yes, billion) into it and there is a ton of private investment going in as well.