One such circle -- in which traffic flows counterclockwise with motorists yielding to cars already in the roadway and with vehicles entering from each leg simultaneously -- has been approved as a concept.
When the Old Alabama Road project is complete, it will become the new State Route 113, and GDOT wants a roundabout to intersect it and Old State Route 113, the existing roadway.
Several other roundabouts for Bartow County are under consideration, including at the intersections of State Route 293 and Grassdale Road; State Route 293 and Ironbelt Road; State Route 293 and West Cherokee Avenue and Fite and Wofford streets; State Route 293 and Hamilton Crossing Road; the Interstate 75 interchange and Old Allatoona Road; and the interstate interchange and Red Top Mountain Road, according to GDOT's website.
The U.S. Department of Transportation and Federal Highway Administration issued guidance on the topic.
"Roundabouts are the preferred safety alternative for a wide range of intersections. Although they may not be appropriate in all circumstances, they should be considered as an alternative for all proposed new intersections on federally funded projects, particularly those with major road volumes less than 90 percent of the total entering volume. Roundabouts should also be considered for all existing intersections that have been identified as needing major safety or operational improvements. This would include freeway interchange ramp terminals and rural intersections," the statement says.
Last year, state officials revised Georgia's roundabout policy to require consideration of the circles as an alternative and an analysis of the possibility if certain thresholds are met. The change also allowed multi-lane roundabouts.
Motorists could be seeing a lot more of them in the future. According to Georgia's policy, roundabouts will be considered in new or reconstruction projects, for existing intersections that have been identified as needing major safety or operational improvements, and in all requests for signals at intersections.
Before-and-after studies of 55 intersections across the country prove roundabouts are safer, according to GDOT. The agency cites a 35-percent decrease in crashes, 76-percent decrease in crashes with injuries, 81-percent decrease in fatal or incapacitating crashes for single-lane urban roundabouts and 71-percent decrease in fatal or incapacitating crashes for single-lane rural roundabouts.
Experts say roundabouts have 75 percent fewer conflict points than traditional traffic light intersections and the conflict points are different -- instead of high-speed, high-angle and high-energy points, roundabouts have low-speed, low-angle and low-energy points.
Although they need more land than traditional intersections, roundabouts are expected to save money through decreased maintenance costs. They could cost more to install than intersections with traffic signals, but if the intersection does not already have turn lanes, construction costs for either could be similar, according to GDOT.
For more information, visit www.dot.state.ga.us/travelingingeorgia/roundabouts.