The Road Circle Tool builds a closed, circular loop based on the currently selected road style. It can be used to build roundabouts and other circular road features. The tool builds the circle from four connected roads, each making a single 90-degree turn.
Click the Road Circle Tool button.
Optionally, click the desired road style in the Library Browser if you want to build a road of a particular style. If no road style is picked, a basic default style is used.
Right-click and drag from the location of the center of the circle to the desired radius.