Unpacking roundabouts, traffic circles, and mini-circles

There is a lot of confusion when approaching roundabouts (more commonly known as “traffic circles” in South Africa) and their much smaller offspring, the “mini-circle”. KEVIN VAN DER MERWE, executive manager – certification and operations at the Road Freight Association, explains the differences and how drivers should behave when approaching each one.

Some motorists come to a complete stop at a circle, treating it as a four-way stop and wanting to proceed in the sequence that they stopped. This is usually the same driver who only reduces speed at a four-way stop, demonstrating some strange and unpredictable behaviour. This goes entirely against what traffic rules are designed to do, which is to ensure the predictability of drivers’ responses to road environmental inputs, observations, and road traffic signs. It is when drivers respond in an unpredictable manner that crashes and road conflict are most likely to occur.

Traffic circles and mini-circles are not the same, and different rules apply to each.

The biggest difference applicable at a traffic circle (roundabout) is that the circle is elevated above the roadway and often uses curbing to physically impose the position of the circle and channelling islands. These are used as physical obstacles preventing vehicles from easily driving over them without sustaining damage.

The physical nature and presence of the circle (roundabout) compel motorists to drive around it. They require more space and can only be constructed in large intersections, so their planning is generally required at some stage before the development of an area or suburb.

The dimensions and steerability of the vehicles using traffic circles will also dictate the size of the traffic circle. Other factors – such as topography and whether buses and articulated commercial vehicles (CVs) frequently use the area – will impact on the decision over whether to use a traffic circle or some other method of traffic control (such as stop signs or traffic signals) at an intersection.

When approaching a traffic circle, certain duties are imposed on a driver. You should:

• Reduce speed and stop if necessary.
• Move around the traffic circle in a clockwise direction.
• Obey all road traffic signs, markings, signals, and rules.
• Yield the right of way to pedestrians and traffic from the right already in the traffic circle, particularly when the vehicles are close enough to be a danger to you as your vehicle enters the traffic circle.
• If your intention is to take the first exit from the traffic circle, you should indicate left when approaching the circle. For all other exits out of the circle, indicate left while in the circle, in good time prior to the exit being taken.