Why Roundabouts?

What is a roundabout?

A roundabout is a type of circular intersection with yield control of entering traffic, islands on the approaches, and appropriate roadway curvature to reduce vehicle speeds. Modern roundabouts are different from rotaries and other traffic circles. For example, roundabouts are typically smaller than the large, high-speed rotaries still in use in some parts of the country. In addition, roundabouts are typically larger than neighborhood traffic circles used to calm traffic.

Why consider a roundabout?

Compared to other types of intersections, roundabouts have demonstrated safety and other benefits. Roundabouts:

> Improve safety

• More than 90% reduction in fatalities*
• 76% reduction in injuries**
• 35% reduction in all crashes**
• Slower speeds are generally safer for pedestrians

> Reduce congestion

• Efficient during both peak hours and other times
• Typically less delay

> Reduce pollution and fuel use

• Fewer stops and hard accelerations, less time idling

> Save money

• Often no signal equipment to install, power and maintain
• Smaller roundabouts may require less right-of-way than traditional intersections
• Often less pavement needed

> Complement other common community values

• Quieter operation
• Functional and aesthetically pleasing

Where does this information come from, and where can I learn more?

This informational page comes courtesy of the Federal Highway Administration. Check out more resources below!

Where can I watch City Manager John Williams explain roundabouts?

On the "Ask the City Manager" short video series on YouTube or yourwestlinn.com!

Did English progressive rock band Yes really make an 8 minute song about roundabouts in 1971?

Yes they did, and it's like catnip for our Planning Department. Planning has nothing to do with building West Linn's roundabouts, but we appreciate their good taste.

* “Safety Effect of Roundabout Conversions in the United States: Empirical Bayes
Observational Before-After Study.” Transportation Research Record 1751, Transportation
Research Board (TRB), National Academy of Sciences (NAS), Washington, D.C., 2001.
** NCHRP Report 572: Roundabouts in the United States. National Cooperative Highway
Research Program, TRB, NAS, Washington, D.C., 2007.