This AutoCAD routine from Raymond Rizkallah converts a polyline, line, or arc into a series of arrows. This could be very useful for showing direction.
Load the LISP file, then run the command ARB. Select a polyline, line, or arc, noting that the arrow direction is determined by the pick location. Specify the arrowhead length in drawing units and press Enter. The selected entity will be replaced with a series of arrowheads and arrowhead tails, forming a chain of directional indicators. If you are not happy with the arrowhead size, a single "U" will undo the entire command, and you can easily repeat the process. See the image below for a sample of before and after.