What is a traffic roundabout?
A traffic roundabout is a type of intersection control device with a central island that allows freer movement of vehicles than traditional signalized and signed intersections.
Traffic enters the roundabout and circulates counterclockwise, to the right of the central island. Vehicles entering the roundabout must yield to all traffic already in the roundabout.
- increase traveller safety
- reduce travel delay
- are economical
- reduce unnecessary idling and air pollution
- may improve the appearance of streets and intersections
Roundabouts have fewer conflict points, slower speeds, and are easier to negotiate than other traffic management methods. There are fewer collisions and fewer injuries from collisions when roundabouts are used. Freer flowing traffic allows for reduced travel times and reduced environmental impacts.
Roundabouts are safe and efficient, but they are not the ideal solution for every intersection. The operations and maintenance expense of roundabouts is less than that of traffic signals. As with the decision to install traffic signals and other control devices, numerous factors are evaluated when deciding the best control for an intersection. Life-cycle cost, land requirements, safety, operations and other factors need to be considered.