hmm.. really good tutorial, except for one minor thing..
I think I would have added one more step in this tutorial, telling people to add a gaussian blur
on the asphalt layer. Not a big one, it's only about a radius of like 0,3 or so, but it will help. It eliminates the edges of the aphalt grains, which i thougt were a little bit too clear in this example. I understand, of course, that the edges are important, since you wouldn't be able too see the grains at all without them, but that is why you should go with such a low radius. It worked for me, but maybe you'll have to experiment with it..
otherways, that was great!