I have created some tools to create roads that follow the landscape nicely. I just define a set of points for the road, create a spline and make a couple of triangles along it and match the height of each vertex to the terrain. It works great so long as the terrain is flat ... I will have to figure out a better way to match the height, maybe flattening the terrain under the road but it's hard to get it to fit perfectly. And I will probably have to come up with an explanation for the existence of asphalt in my fantasy world