Traffic approaching the intersection must drive around the circle and yield to those cars which have already entered the circle. Designated either by markings or a curbed island, a roundabout breaks up a driver's line of sight. The driver is less sure of what to expect ahead and will generally lower his or her driving speeds. Roundabouts can also provide a refuge for pedestrians when they are crossing the street. Other traffic calming devices may be more effective in reducing your traffic problems.
Roundabouts are among the more expensive traffic calming devices.
Considerable evaluation is required before a location can be approved for this treatment.