Go back through my Seaboard Central 2.0 thread, and you'll see no less than three or four attempts to build roads on my layout, including joint compound, spackling, and styrene. Thanks to tips by DKS, Chris333, and others, I persevered and had the most success with 0.060" black styrene, light gray rattle can primer (base road color), chalks (weathering), and colored pencils (road striping). While I didn't put a crown in my model road, I think that could have been easily done by scribing down the centerline on the underside of the styrene and slightly bending it.
Your second attempt with spackling looks really good. The reason I tore out my spackling road was because it was so soft. If you insist on a wet product, this is where Woodland Scenics' Smooth-It shines, because it dries much harder. I used Smooth-It successfully on the Virginia Central, but I didn't use it on the Seaboard Central because it's so labor intensive. Styrene is much easier, even around the tracks, where a paper template and some tracing will get you the proper shapes.
That said, some paint and weathering on your road, though, and you're on your way!
DFF
