U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
This diagram is of a single-lane mini-roundabout in the center of a four-way intersection. Roadways are shown entering the roundabout from the north, south, east, and west. The roadways entering the roundabout are shown with one lane on each side of a splitter island, with the one on the right of the splitter island used to enter the mini-roundabout and the one on the left used to exit it.
In the center of the diagram is a cobbled central island surrounded by a solid yellow edgline, noted as optional. A note indicates the central island may be either mountable, as depicted, or painted yellow. A circular roadway surrounds the central island and is marked with optional white arrows running in a counterclockwise direction that indicate vehicles may either go straight or turn left around the circle onto an adjacent road. Solid white edgelines mark the outer edge of the circular roadway at the four points where splitter islands are located to separate opposing traffic entering and exiting the circle. Broken white edgelines mark the point where vehicles entering the mini-roundabout should yield to oncoming traffic, although the area of the roadway to the right of each splitter island, where exiting vehicles travel, is not marked.
Three of the four triangular splitter islands displayed are drawn as mountable islands. Solid yellow edgelines surround each of these mountable splitter islands, with the exception of the white edgline at the flat part of the triangle, where the splitter island marks the diameter of the roundabout itself. The fourth splitter island is formed by two sets of double yellow lines on the long sides of the triangular splitter island. The diagram notes that splitter islands may be formed by two sets of double yellow lines or may be mountable. A crosswalk composed of a row of closely spaced white lines parallel to the flow of traffic is shown crossing all lanes and the narrow part of each splitter island.