Mini roundabouts are less common in North America, but frequently used in the UK. Their footprint is smaller, making them suitable for retrofit situations with right of way constraints (and lower cost). They are also commonly used where truck U-turns are not needed, so achieve all the safety benefits of compact modern roundabouts at a much lower cost. They are all truck apron, and in the UK are sometimes just paint on the road.

St. James, Minn.: Trucks at mini-roundabout video