Select the junction you want to edit.
Click the Edit Junction button on the Junctions toolbar or select Edit Junction from the Junctions drop down menu. The Junction Properties dialog is displayed.
The Junction Properties dialog is modeless so you can leave it displayed while you continue working.
The left hand pane is a tree view list of the roundabout elements including the traffic circle and the arms. If only the General element is listed on the left then you did not select a junction; pick a junction now. Click + to expand the tree view.
The right hand pane lists the details of the selected element.
The Junction Properties Diagram is used to explain the terminology. Select the Diagram button to display it and click again to hide it.
In many of the pages within the Junction Properties dialog, there are Max and Min columns. These refer to the limiting values recommended by the design standard that you have chosen to use. In many cases you will be permitted to exceed these values but they appear as warnings on the drawing and as exceptions in a design check report.