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A roundabout is a circular intersection or junction of two or more streets or highways. By design, roundabouts are intended to move traffic more smoothly and consistently with fewer and less severe collisions than other types of intersections. All roundabouts are characterized by special approaches, instructional signage, and a center circle island that often is landscaped. Many roundabouts have “splitter” islands at exits to separate exiting and entering vehicles, pedestrian crossings, sidewalks, and bicycle lanes.

Roundabout traffic moves in a counterclockwise fashion around a center island. Drivers exit at the adjoining street or highway of their choosing. Unlike traditional intersections that control traffic flow with lighted signals or stop signs, roundabouts are yield-only, meaning that unless there are vehicles in the roundabout, drivers approaching the roundabout do not have to stop. In a common four-leg roundabout, a driver making a right turn takes the first exit; the second exit to continue going straight; and the third exit to turn left.

Yes, in many ways, they are. Research shows roundabouts move 30-50 percent more traffic, have far fewer “accident points” (16 compared to 56 for traditional intersections), reduce fatal crashes by 90 percent, save $5,000 per year on average in electricity and maintenance costs, cut vehicle emissions and fuel use, and last 15 years longer than intersections with traffic signals.

According to traffic research studies, it won’t. The National Cooperative Highway Research Program reports that there are 76 percent fewer crashes with injuries on roundabouts compared to traditional intersections. The crashes that do take place on roundabouts usually are sideswipes, not the more severe right-angle “T-bone” crashes.

With the way the roundabout at the Indiana 64/162 intersection is constructed, it won’t be. The single-lane roundabout is being designed to accommodate trucks with a 65-foot wheelbase (WB-65). WB-65 tractor-trailers are the size of semi-trucks that travel interstate highways. Most trucks that travel on 64/162 are WB-40 to WB-50.

Also, the roadway leading up to the roundabout will be 16 feet wide from the raised median to the curb. The final sections of road that connect with the roundabout – known as “approaches” – will be wider than 16 feet.

In addition, a truck apron will be added to the roundabout’s inner circle, allowing additional lane width, larger turning radiuses and better clearance for lowboy trailers.

During prime travel times, there may be a few vehicles lined up to enter the roundabout, but even then it isn’t likely to cause the types of backups seen with traffic lights and four-way stops. Studies by the federal National Cooperative Highway Research Program show that traffic moves smoother, and at 30-50 percent higher capacity, than at traditional intersections.

The project is still in the design phase, but the single-lane, four-leg roundabout will allow vehicles access to both east-west travel on Indiana 64 and north-south travel on Indiana 162, as the intersection is now. Because the roundabout is in a rural area heavily traveled by trucks, farm machinery, and other large vehicles, the dimensions likely will be larger with other features to allow for easier navigation.

In size, most likely. The center circle island may not mound as much as roundabouts in cities, and landscaping may be kept to a minimum to provide for better sight lines in all directions.