A turnabout, roundabout or rotary is a continuously moving traffic circle that flows in one direction and serves as an intersection for two or more roads. Vehicles enter a turnabout by yielding to oncoming traffic, as moving vehicles in a traffic circle have the right of way.
Known as a Michigan left, turnabouts were first implemented in Michigan in 1960 to shorten the left-hand turn wait times at busy intersections. The outside lane of a traffic circle with two or more lanes is designated for immediate exit only. Traffic circles are common in Europe, where they are built for traffic control and aesthetics.