Basically, I want to create a road system that transitions between asphalt and cobblestones. I also want the option of having road markings, while still maintaining a high-res texture.
The only obvious answer to me, is to map out all of the roads in Blender, then UV map it to some massive texture that does all of the transitions for me, however, up close it would look awful unless the texture size was something crazy like 1,000,000,000,000 x 1,000,000,000,000.
Make three textures. One repeating cobblestone texture. One repeating asphalt texture. One combination where you show the transition.
You could also use meshes to cover the seams. It all depends on your design.
HTH
I made you a small material that hopefully will give you a clue on how to make such material
The transition fallof will let you control the size of the transition. You can change the uvs to tile each texture, and at the end you add the stripes over all
