Except for hiking the AT from Springer Mountain, you'll be hard-pressed to get all the way to Gatlinburg by public (or foot-powered?) transit alone. There is a Greyhound bus from Atlanta to Knoxville, which is about 45 minutes from Gatlinburg. Once you get to Gatlinburg, however, you will have access to the city's trolley system, the fifth-largest mass transit system in Tennessee. Find more info about Gatlinburg here: http://vacation.away.com/tennessee/travel-v2-cid321344-gatlinburg-cid400173-travel.html.