For something like a curb, I think the best way to do it would be draw a
polyline, and then convert it into a subassembly. Add Point, Link and Shape
codes (if you want). If you have multiple sizes, make a couple of different
size subassemblies. Make the subassemblies in a seperate drawing, the make a
block of each one. After making the block, save the drawing, and then drag
the block onto your tool palette and set the properties to "explode" on
insert. Now you'll have a nice palette of custom curbs that you can use in
your projects.
Cheers,
Peter Funk
Product Manager
Autodesk, Inc.