a small, flat roundabout (= a place where three or more roads join and traffic must go around a circular area in the middle, rather than straight across) that is shown only by marks on the road, and that it is possible to drive over if necessary

At a mini-roundabout it is important to remember that all vehicles must pass round the central markings, unless they are too large to do so. 在微型环岛，必须记住，所有车辆必须绕过中央标线，除非车辆太大，无法绕过。