First, let me say this software is awesome. I've been waiting for years for something like this, and Mac friendly at that!
I would like to be able to create my own highway shields. There is a nice set built in, but limited for what I would like. I have played around creating symbols, but none have taken the route_num tag. I even mimicked the - color; narrow in the description wondering if that was a key. When you click on an existing shield on a path, it gives you the path attributes, but no attributes on the symbol.
It looks as if you can load your own symbol library, but I can find no information on how to create one, and exporting the existing one didn't help unlock its secrets.
Oh and a bridge without stobs in the middle would cool too