I cannot help you out with Nashville. However, a very good route around Atlanta is US-27 South. Get off I-75 in Calhoun, Ga. and get on Ga. 53 to Rome. Go South to LaGrange and get on I-185 to Columbus. At Fort Benning get on US 280 to Richland. Go straight on Ga. 520 to Albany and get on US 82. US 82 will take you all the way to Jekyl. Great roads, very little traffic, all 4 lane, and mostly 65 mph. Very senic highway. If you are retired or active military you go right by Fort Benning and MCLB Albany. Fort Benning has a great campground. A little longer, but well worth the extra time.