SR20, aka McDonough Hampton Road

Changing road ID #1511002000 functional class from 4 (Minor arterial) to 3 (Principal arterial).
### Description
4 lane road with depressed grass median.  AADT 11,000
### Justification
Continuation of recommended change on SR20 east of this section.  SR20 connects to Hwy 19/41 & I-75.
#### Entire segment
#### County
Henry County