I don't know official policy of page, but they are next to useless. I've never seen signage off of interstates in Georgia on the actual routes. I think they exist purely to appease local cities with additional interstate signage through their towns. For example, as I just looked at Google Street View in Tifton, there isn't even signage at the top of the of the ramp at exit 59. I have a few friends in South Georgia, and they never speak of the loops when giving directions. It's always the state highway number or road name.