Given that either installing a roundabout or adding left turn lanes at the Kingsway and Frederica intersection will cost about $750,000, I can’t see why it’s such a hard decision.
The left turn lanes will improve traffic flow slightly when there are no cars in those lanes, but if there are, the improvement will be negligible since traffic flow will still be limited until the left lane clears and the lights cycle. It will also mean considerable changes to the electrical controls for those lights, thus resulting in higher maintenance and occasional malfunctions, like the one that already occurs there.
As long as you rely on traffic lights, the traffic won’t be flowing in any direction part of the time. When traffic flow in one direction gets a caution light, it will last for five seconds and then the traffic in all directions will get a red light for a couple seconds. To make matters worse, I have observed that when the driver in the lead car gets the green light, they feel they need to add about five more seconds to be safe. When you add all of these human delays occurring during one complete cycle, it means more time when no one is moving in any direction.
The traffic is always moving in a roundabout, and unless there is a major issue with the airport or golf course, it is a much better choice.
St. Simons Island