"Bisect Polylines draws lines bisecting the angle between vertices of a polyline. Length of bisector line is half the distance to the previous vertex in the vertex order of the polyline. Arc segments are treated as straight. Only new style 'lightweight' polylines are supported, not old style polylines."
Notes from Cadalyst Tip Patrol: This routine works as stated and only for polylines. Load the routine BISECTPOLYLINES.FAS and start it by typing BISECT on the command line. Then select the polyline you want to bisect. The command will draw a line that bisects the angle of every vertex on the polyline, so if it is a long polyline, with several vertices, then there will be many bisecting lines drawn, so be careful. But it is a great tool that will allow you to very quickly bisect and angle.