I have a feature class that is the drainage areas of a proposed project. I need the outlines of these drainage areas to be dashed. How do I control the adjoining drainage areas outlines so that the pattern of the dashed lines do not overlap and display as a solid line.
You could use lines created from the polygons once they've been planarized to get rid of overlaps. We typically work with lines, points and polys as part of our normal procedures. In your case, however, it might require an extra feature class, but a line feature class has other benefits, such as allowing symbology categories, definition queries, ease of editing lines, etc.