If you have ARCADY then you can benefit from the automatic 2-way transfer of data between it and Roundabouts. This page lets you choose what you see in the head up display (HUD).
Click Arcady Analysis in the left-hand pane. The Arcady page is displayed. Select Enable ARCADY Link to invoke the link for this roundabout.
If you have a compatible version of ARCADY installed with the link feature enabled, then ARCADY starts automatically and, by default, minimised.
Currently the link only supports normal roundabouts.