When using InRoads to view a horizontal alignment, some of the graphics within the active design file will disappear. Also, if any changes are made to the horizontal alignment (move or delete PI) graphics will disappear.
This behavior is due to the designer possibly copying graphics that has data attached and using the copied graphics to serve a different purpose other than initially intended.
A great scenario is one where a horizontal alignment is copied to create an edge of pavement. Although not visible, when that horizontal alignment was copied, it’s user data was copied with it and whenever there is an action that involves that horizontal alignment, the graphics created from that horizontal alignment is affected also (because of the user data still attached to the copied graphics).
To remove user data from a graphic element, invoke the Remove User Data command. This command is an Application Add-In and is docked under Tools.