Some drivers find roundabouts confusing and counter-intuitive, but in the right situation, roundabouts can have major advantages over a traditional stop sign or signal-controlled intersection. These benefits include an increase in driver safety, a more efficient traffic flow, a more aesthetically pleasing intersection, lower construction and maintenance costs, and a positive environmental impact.


The greatest benefit of roundabout implementation is the increase in motorist safety. Reasons for this advantage include:

  • Drivers are approaching the intersection at a reduced speed and typically drive slower around a curve.

  • Drivers aren’t speeding up to beat a yellow traffic light.

  • The geometry of roundabouts prevents the possibility for T-bone or head-on collisions, which are the most fatal.

  • Fewer turning directions results in fewer potential contact points between vehicles and pedestrians.

Studies by the Insurance Institute for Highway Safety (IIHS) and Federal Highway Administration have shown that roundabouts typically achieve:

  • 37% reduction in overall collisions

  • 75% reduction in injury collisions

  • 90% reduction in fatality collisions

  • 40% reduction in pedestrian collisions

Graph provided by the Washington State Department of Transportation

Graph provided by the Washington State Department of Transportation


According to one study, replacing traditional traffic signals and 4-way stops with roundabouts resulted in the following environmental benefits:

  • 32% reduction of carbon monoxide emissions

  • 34% reduction in nitrous oxide emissions

  • 37% reduction in carbon dioxide emissions

  • 42% reduction in hydrocarbon emissions

Studies have also found that without the necessary start and stop used at traditional intersections, vehicles use up to 30% less gasoline as traffic moves more efficiently through roundabouts. At 10 intersections studied in Virginia, this savings amounted to more than 200,000 gallons of fuel per year.


For more information on the benefits of roundabouts in your community, please contact one of our experts today.

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