A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
SmartArts are great - as long as you do exactly what they want you to do. As soon as you try anything that they didn't foresee, then they'll fight you, kicking, biting and screaming all the way.
The lane crossover thingy isn't something SmartArts like to do, so I suggest setting up the diagram as close as you can get, then select the "Covert to shapes" command. You can't undo this and go back to a SmartArt, but once you have shapes, ungroup them and you can add any bits you like.
Good way to do achieve strange effects not part of the SmartArt logic.
Cheers, Blackadder