I proudly present you the new "Road-Generator". You can create complete roads within a few clicks:
1.) You see a normal terrain:
2.) Paint the road (pink/white) on the heightmap. The white color is the line for the terrain and the pink line is for the texture. Then choose a texture for the road and generate it:
3.) The terrain with the generated roads:
Here is the screen you can see the difference between "before" and "after". You can see that it not only paint a way on the terrain, it also deforms the terrain under the road: