secondary alignment

What is the issue? Roadway Designer provides "secondary alignment" command in Corridor menu as well as an icon from the toolbar.

Actually the problem is I'm unable to use the option and I dont understand where to use the option correctly.
Please explain the procedure.
Regards
Yamini

What do you want to do with secondary alignment?

In station location, loop lines are to be defined which are not designed (as same gradients as main line are followed). Can we use secondary alignment for this purpose.

Regards
Yamini

Could you provide a picture?

Secondary Alignment purpose is to change the direction of calculation since the secondary alignment is found.