• American communities are more frequently seeing benefits in having traffic circles, including lower costs than overpasses or underpasses and reduced maintenance compared with grade-level intersections.
• Eugene Russell, director of the Center for Transportation Research and Training at Kansas State University, says reduced numbers of T-bone and head-on crashes are among the benefits of roundabouts, along with no idling engines at red lights.
• Omni-Means Engineers and Planners of Sacramento,Calif., targets roundabout business and says they are harder to design and easier to build than right-angle meetings.

From the article:

The roundabout, a circular intersection in which traffic flows through from incoming streets in one direction around a central island, is booming in the U.S.—so much so that some engineering firms see it as a straight-on opportunity. ...