Those are traffic circles or rotaries, not roundabouts.<p>Traffic circles are not roundabouts (nor are they &#x27;traffic calming circles&#x27;). Eg, <a href="http:&#x2F;&#x2F;www.heraldtribune.com&#x2F;article&#x2F;20090621&#x2F;columnist&#x2F;906211023?template=printpicart" rel="nofollow">http:&#x2F;&#x2F;www.heraldtribune.com&#x2F;article&#x2F;20090621&#x2F;columnist&#x2F;9062...</a> (warning: that&#x27;s the &quot;print&quot; page, rather than having three differet pages):<p>&gt; Often there is considerable confusion about roundabouts and traffic circles or rotaries. People often say that they don&#x27;t work in the Northeast (especially in New York and New Jersey) and are being removed, so why build them here [in Florida]? ...<p>&gt; A study done by Per Gardner at the University of Maine found that traffic circles have 3.5 to 6.5 times more crashes than roundabouts. ... Because of these growing concerns, the last design reference to traffic circles in the U.S. design standards was in 1965.<p>&gt; Then came roundabouts. The first roundabout in America was built in 1992 at an intersection in Gainesville. Although traffic circles and roundabouts use a circular design, they operate very differently. Traffic circles are very large and are designed for high-speed vehicle operation. Roundabouts are designed as small as possible, 16 to 180 feet wide, and operate at 15 mph to 25 mph.<p>See also <a href="http:&#x2F;&#x2F;www.wsdot.wa.gov&#x2F;Safety&#x2F;roundabouts&#x2F;BasicFacts.htm" rel="nofollow">http:&#x2F;&#x2F;www.wsdot.wa.gov&#x2F;Safety&#x2F;roundabouts&#x2F;BasicFacts.htm</a> and <a href="http:&#x2F;&#x2F;www.wcroads.org&#x2F;sites&#x2F;default&#x2F;files&#x2F;pdf&#x2F;media&#x2F;Modern%20Roundabout%20Myths.pdf" rel="nofollow">http:&#x2F;&#x2F;www.wcroads.org&#x2F;sites&#x2F;default&#x2F;files&#x2F;pdf&#x2F;media&#x2F;Modern%...</a> .