Some large traffic circles provide straight path for major movement with higher speed. No parking is allowed on the circulating roadway. Some larger traffic circles permit parking within the circulating roadway. No pedestrian activities take place on the central island. Some larger traffic circles provide for pedestrian crossing to, and activities on, the central island.
All vehicles circulate around the central island.
Splitter Island Required. Table S.2 presents some advantages and disadvantages of roundabouts. Advantages and Disadvantages Comparison Category Advantages Disadvantages Safety - There are a reduced number of conflict points compared to uncontrolled intersection. Lower operational speeds yield fewer and less severe accidents. Since roundabouts are unfamiliar to the average driver in the US, there is likely to be an initial period where accidents increase.