Horizontal Alignment - In the Plan Window you have the capability of horizontally controlling the L-Line position. This is done by creating Plan Points along the length of the road. The L-Line is based on a P-Line field traverse.
Vertical Alignment - In the Profile Window you have the capability of vertically controlling the L-Line position. This is done by creating Profile Points along the length of the road.
See the following for more information on working with alignments: