Meridian Ave S and 240th St SE Roundabout

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Learn how to safely navigate a single-lane roundabout

• Traffic moves counterclockwise in a roundabout.
• Look and stop for pedestrians waiting to cross.
• Look to your left. Yield to vehicles in the roundabout.
• Wait for a gap in traffic before entering the roundabout.
• Pedestrians should always use the crosswalk. Never cross to the central island of the roundabout.
• Bicyclists can use the roundabout as a vehicle or use pedestrian paths with the same rights and responsibilities. 
• Oversized vehicles can ride up on the slightly-raised truck apron, which is designed to provide more space to complete the turn.

Roundabouts help to reduce accidents, reduce congestion and improve traffic flow, and improve air quality.

Improve safety

Roundabouts help reduce the likelihood and severity of collisions because of low travel speeds at intersections, one-way travel, and no light for drivers to try to beat.

Studies by the Insurance Institute of Highway Safety (IIHS) and Federal Highway Administration (FHWA) show that roundabouts:

• Reduce overall collisions by 37%
• Reduce injury collisions by 75%
• Reduce fatality collisions by 90%
• Reduce pedestrian collisions by 40%

Conflict points are also reduced with roundabouts compared to traditional intersections.

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Reduce congestion and improve traffic flow

Roundabouts allow for continuous flow of traffic. Drivers are not required to stop - only yield - so the intersection can handle more traffic in the same amount of time. 

Studies by the FHWA have found that roundabouts can increase traffic capacity by 30 - 50% compared to traditional intersections. The IIHS also found that roundabouts contributed to an 89% reduction in traffic delays. 

Improve air quality

Roundabouts can help improve air quality by lowering vehicle emissions from idling. The IIHS found that installing roundabouts instead of traffic signals or stop signs reduces carbon dioxide emissions by 23 - 34%.