We’re starting to see more Roundabouts installed around the upstate. They’re used in lieu of standard intersections which might have stop signs or a traffic light. Think about the last time you used a 4-way stop intersection, and how much time is lost when it’s someone else’s turn to go, and they sit there for a few seconds. Multiply that nearly every car that has to stop, and you can see how not stopping, or yielding has big benefits.
The Difference Between a Roudabouts and a Traffic Circle
Traffic circles are typically larger – they allow vehicles to enter at a higher rate of speed, and often have signals or stop signs to reduce potential traffic. Roundabouts are smaller, and primarly what you see around Greenville, in areas like the CU-ICAR campus. Roundabouts are designed to make vehicles negotiate a sharper turn, forcing you to slow down.
Two-lane Roundabouts: How to Pick a Lane.
- Right Lane: for going straight through or taking the first right only.
- Left Lane: for going straight through, making a left-turn or a u-turn only.
- Traffic entering the circle should yield to vehicles in the circle.
- You should pick your lane before entering the circle.
- You should only change lanes in the circle to move from the inner lane to the outer lane to exit on the far left.
Roundabout on the CU-ICAR campus in front of the TD Bank Building. There are two lanes.
Traffic Circle in the Donaldson Area. Note the larger diameter and easier entry-angles. Incoming traffic should yield to traffic already in the circle.
They can also be used in parking lots, the one below is along Woodruff road, in front of Cabela’s. As in all roundabouts, you are expected to yield to traffic already inside the circle, but should avoid stopping at the entrance if you are able to enter. Note the triangular yield markers, which indicate where you should be yielding if necessary.
Roundabouts are much more common in some other countries, including Australia, the United Kingdom and France. We visited Grand Cayman last year, which has many more roundabouts and traffic circles than traditional intersections, and they drive on the left side of the road, which made negotiating them particularly difficult, but by the 2nd or 3rd day we were there, it started to feel pretty natural.
Traffic Circle at the entrance to the Sierra Nevada Brewery.
Bonus: Double Crossover Diamond Interchange
While we haven’t seen one of these around Greenville just yet, a couple weekends ago we visited Sierra Nevada Brewery, and when you get off I-26, you use one of these on the bridge to cross over. It’s a pretty odd-looking design, especially since you momentarily cross over into the left side of the road, but apparently it’s more efficient than the typical interchanges found at offramps. You can read more about the Double Crossover Diamond Interchange on Wikipedia.
