From I-85 west, I would take exit 149 (US441) south to right before you get to Eatonton and take the James Martin bypass to GA State Road 16 west. Continue on GA 16 west through Monticello, Jackson, Griffin. After you go under I-85, bear rightto continue on Rt 16 which merges with US Alt 27 and 29. After you get through Newnan turn left to stay on 16, alt 27 and 29. This will bring you back to I-20. GA 16 is a 12 lane road. You will need to plan your stops at Walmarts or fuel stops. This adds about 100 miles to your trip and because it goes through small towns it adds more time. We like it because it's scenic farm country and less stress.