One of my random passions (along with dairy products, Vector and Shreddies cereal, cherry pie and basketball) is the roundabout intersection. After preaching the merits of roundabouts to friends, students and strangers for years I realized my personal website was lacking information on this glorious invention and created this page in response. Last Updated March 24, 2022.

Reasons Why The Roundabout Is Superior to Other Intersection Options

  • Safety – Roundabouts virtually eliminate any possibility of a “T-bone” or head-on collision, the most dangerous types of collisions. Further, they naturally encourage all approaching vehicles to slow down prior to entering rather than encouraging vehicles to speed up prior to entering as a traffic signal approaching yellow or red does. Any collisions that do occur in a roundabout are typically minor side-to-side collisions which pose much less risk of personal and vehicle harm.
  • Traffic Flow – When traffic volume is low (at certain times of the day or always), roundabouts almost completely eliminate the possibility that any vehicle will have to wait and idle for more than a few seconds. This is in direct contrast to traffic lights where cars traveling in one direction must wait for those traveling perpendicular even in the middle of the night with no one else around. When traffic volume is higher, roundabouts provide a more even and steady flow for all directions of traffic than traffic lights or stop signs.
  • Environment – Roundabouts allow cars to consume less fuel due to the significantly reduced idling time and reduced need to accelerate from a standstill With no electrical feed needed for signal lights the electrical burden of roundabouts is also lower.
  • Cost – Roundabouts require fewer. signal lights and less electrical infrastructure and paving than signalized intersections.
  • Beauty – A well-designed and well-functioning roundabout is far more beautiful and less jarring to the eye than a busy signalized intersection!

False Arguments Against Roundabouts

  • Complexity – It is argued that roundabouts are too complicated for drivers who are unfamiliar with them and the resulting confusion may cause more accidents rather than reducing accidents. This has always been a short-sighted argument given that drivers all over the world have been successfully navigating roundabouts since the invention of the automobile and further that the prevalence of roundabouts is increasing, rather than decreasing, throughout the world allowing drivers to become more and more familiar with them. Further, as discussed above, accidents resulting from roundabouts are likely to be far safer than those resulting from signalized intersections and to quickly reduce as drivers increase familiarity. Also lacking from this argument is recognition that many signalized intersections and 2-way, 3-way stop sign intersections appear familiar and simple but can vary widely in format creating a less noticeable but even more dangerous type of complexity.
  • Foreignness – Roundabouts are sometimes dismissed as being suitable in Europe and other countries with a long history of usage but too foreign to introduce into North America or other regions without the same history. The steady and increasing introduction of roundabouts in North America and elsewhere serves to directly undercut this argument.
  • Pedestrian Impacts – It is argued that roundabouts do not sufficiently prioritize pedestrians and that the interaction between pedestrians and vehicles at a roundabout are confusing. While this may be true in extreme situations described below, roundabouts that include crosswalks or traffic signals as well as triangular islands for pedestrians to wait can offer the best of both worlds for both drivers and pedestrians.
  • Safety – See safety discussion above

Limited Situations Where Roundabouts Are Less Preferable

  • Insufficient space for a roundabout to replace a tight signalized intersection or four-way stop
  • Extremely high traffic volume where the roundabout itself could end up completely jammed for long periods of time.
  • Situations where pedestrian volume and priority far exceeds vehicle volume and priority

Other Internet Resources Related to Roundabouts


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