Roundabouts can seem like an evil plot to confuse and baffle a driver. Why would you want to have something so confusing? There are three reasons why roundabouts, traffic circles and traffic calming circles were formed.
Normal intersections meet at 90 degree angles which during a crash, the crash is usually a T-bone (T-bone = a car going through an intersection is struck by an oncoming car in the side of their car, thus making a shape of a T). In a roundabout, the crash is usually less than a 45 degree angle and the vehicles are moving in the same direction. This would result in a less violent crash and causing less severe injuries. Also more often, by my estimation, the car is more likely repairable. The key is that people have less chance of injury.
MAINTAINING THE FLOW
A roundabout helps maintains the flow of traffic. The most effective intersection, at best, has one flow of traffic stopped at all times. We do have flashing (demand) green lights on side streets, which facilitate longer green light times for the heavier flow of traffic. But in a roundabout, traffic is flowing and only stops momentarily when traffic is in the roundabout.
It is more cost efficient to build a roundabout than to build an overpass, therefore, saving the city a great deal but installing a roundabout.
A roundabout is not to confuse and baffle a driver, but is more efficient, safer and more cost effective. Which is why I tell my new driving students that I believe they will be seeing more and more roundabouts in their lifetime than before.