Hyw 27 Chattanooga South to I10

ress's post is good. Take the bypass around the east side of Rome. In fact take I-75 to Calhoun and GA-53 to Rome. You'll miss all the mess coming out of Chattanooga and the miles of 45-25 thru Summerville GA. I would say the slow spots are LaGrange and Carrollton, neither has a bypass. Get fuel in Columbus, you should make Tallahassee with no issue, less than 200 miles.
Also good COE parks on West Point Lake near LaGrange. Small city campground in Colquitt, GA. very small and right on US-27.