In a move that's been a long time coming, CalTopo now supports line styles.
When creating or editing a line, there's now a style option next to color, defaulting to solid. Click on it to choose a line style.
A number of directional and nondirectional styles are provided, but if you'd like to see something specific, let me know.
Unfortunately, due to limitations in the Google Maps API, styles are not available on polygons. Supplying polygon styles would mean dropping all the individual symbols on the map myself, which is doable from a technical perspective - that's how I support styles in the PDF generator and in the OpenLayers offline version - but might cause performance issues for large polygons. It might get added at some point.
So what to do when you carefully draw a route and then realize you want the arrows to point in another direction? Or when you want to add a line on top of a polygon boundary in order to style it? That's the subject of the next blog post: line modification.