Modern roundabout traits
- Designed to slow down traffic1
- Yield signs at entry points1
- Traffic flows in counterclockwise direction1
- Either one or two lanes1
- Raised central island2
- Reinforced concrete area, known as a truck apron, that rings central island to help larger vehicles turn2
Rules of the road
- Look to your left for oncoming traffic.3
- Yield to drivers already in roundabout.3
- Look for pedestrians before entering and exiting.3
- If a multilane roundabout, stay in your lane.3
- Do not stop.3
- Do not pass oversize vehicles.1
- If emergency vehicle appears, exit roundabout to let it pass.1
- Use right-turn signal when exiting.1
How to pick the correct lane in a multilane roundabout3
- Look for signs or pavement markings indicating where to make turns/continue straight.
- Select right (outer) lane to make right turn or continue straight.
- Select left (inner) lane to make left turn, U-turn or to go straight.
- Identify correct lane before entering roundabout.
Top eight states for roundabouts4
More than 300
- North Carolina Between 200 and 300
1 Intersection Safety – Roundabouts a Safer Choice, U.S. Department of Transportation, Federal Highway Administration, 2019. 2 Intersection Safety Roundabouts, U.S. Department of Transportation, Federal Highway Administration, 2019. 3 How to Drive a Roundabout, Washington State Department of Transportation, 2019. 4 Roundabouts Database – Reports, Kittelson & Associates Inc., 2017.
For all the benefits of roundabouts, this unfamiliar traffic pattern can throw drivers for a loop. If a newly installed roundabout along your commute has you going in circles, you’re probably not alone. Yet, these intersections are becoming increasingly common: there are more than 5,000 roundabouts in the U.S. 1 (The city of Carmel, Indiana, is the roundabout capital, with more than 100 roundabouts!) 2
So, how is a roundabout different from a traffic circle or rotary? For one, they have a smaller footprint. Also, there are no stoplights or stop signs, and entering drivers must yield to drivers already in the flow of traffic.3
Why are roundabouts being used more?
In short, they help improve safety and traffic. According to research by the Insurance Institute for Highway Safety (IIHS), roundabouts reduce fatal and incapacitating injury crashes by 90 percent, injury crashes by 76 percent and all crash severities combined by 38 percent.4
Wen Hu, senior research transportation engineer at IIHS, tells Amica, “I think more roundabouts are going to be built in all states because more people are realizing the traffic and safety benefits roundabouts could bring.”5
What makes roundabouts safer than traditional intersections?
Their circular design forces cars to slow down and lowers the possibility of head-on or T-bone collisions. It also reduces some drivers’ tendencies to speed up because there is no yellow traffic light to “beat.”6
Roundabouts also reduce congestion, because more cars can flow through them at once compared to a traditional intersection. Cars don’t need to stop and start as they do for traffic lights, resulting in better traffic flow, as well as lower pollution and fuel use. There’s a cost savings for municipalities, too, since there are no traffic signals to maintain.7
While it may take some time getting used to them, roundabouts eventually tend to win over the public, Hu says. “We did surveys of drivers in several communities, and after the construction was completed and drivers got a chance to drive at the roundabouts, the drivers are more likely to be in favor,” Hu explains.