MAKING TILED TEXTURES LOOK BETTER USING ONE EXTRA MAP.
first, make a uv image of the part of your model that will have one texture tile on it.
then make a basic texture.
Now bring your UV image back, and put it on top of the basic texture.
Now you paint scratches etc inside the edges, without crossing them
you now have one basic texture, and one that is very battered.
In max, apply the basic texture to the whole model, and apply the second one to a polygon on the model, so it gets mat id 2.
Then just pick a few random poly's, and change their id to 2.
Because I did'nt paint over the lines earlier, It does'nt matter wich ones I choose.
Now the road has an ok amount of detail, and does not repeat itself much