As a Seagrove resident, I'd say the jamup at 30A/395 is so infrequent as to render ANY investment there a waste. It only happens at the absolute peak, like 4th of July weekend. The rest of the time, it flows just fine. As I've often said, this isn't Atlanta, so what's the rush anyway?
If we just HAVE to spend some county $, let's put up a traffic light and turn it on only on peak visit times. The rest of the time, I'd bet the current 3-way stop would flow more traffic than a light. It sure seems that the Rosemary light actually impedes traffic flow rather than helping it, both on 30A and on Barrett Circle.