Processing planar graphs

When the Input coverage contains linear data belonging to different planar graphs, the data will be maintained in the Output coverage.

For example, with coincident or colinear arcs such as arcs representing utility cables at different levels or a road following a stream, the coincident and colinear line segments will be preserved. However additional vertices may be inserted.

In the case of intersecting arcs such as a road passing over a stream, nodes will not be inserted at the apparent intersection.