If you have an existing overhead or underground line and you want to add ducts and/or conductors, communication cables, or gas pipes, you can do so in the following ways:
on the container to add the lines to the container. The line feature's geometry follows the segment's if they are different. For more information, see
To Modify Containment of Line Features.
The new line is added to the existing segment and can be seen when you display Feature Info on the segment.