Editing Polylines
To taper the width of individual polyline segments
- From the Modify menu, choose Object>Polyline.
- Select the polyline to edit.
- Enter e (Edit Vertex).
The first vertex is marked with an X. Move to the appropriate vertex with Next or Previous.
- Enter w (Width).
- Enter new starting and ending widths, and press ENTER to move to the next vertex. Repeat steps 4 and 5 for each segment.
- Enter u (Undo)to reverse actions back to the start of PEDIT.
- Enter x (Exit) to end editing vertexes.
- Enter x (Exit) again to end the command.
Modify toolbar: 
Command line equivalent: PEDIT