Terminus could be around macon area !
1.lets look at some maps it's around macon area but likely not withen Macon, so maybe Macon will be Alexadria ?
2.also they focused alot ! on macon both Michonne and the Governor pointed to them on the map
You can see this, particularly, when you look at the little inward point (almost like a nose on a face in profile) directly south of Columbus.
also heres a better map of GA, railroads,
and old map of GA,
Here <better one
Now i hear terminus is some type of railroad stop near macon, it' also fits the out line of the western part of the State were it would be, and it does seem to be more south of atlanta