It's a good colour David but perhaps a little 'heavy'. I've not modelled tarmac roads but have used fine sandpaper/acrylic paint for lanes and have also used block paving finishing sand (also known as silver sand).
The roofing shingles are left over from the new roofing on our house. I saw a post of a modeler in the US that used the back of shingles. He painted it with a light coat of gray paint, and then sprayed a light coat of India ink on it. I have not done that yet. here is his posting. Scroll down toward the bottom.
The problem with all these sheets of material, is that there are un disguisable joints. As I have posted elsewhere, roads are made of particles too fine to see at our scales and simple matt paint is sufficient, especially if put on modelled Polyfilla or similar (cheaper) fillers. Then you can model in the camber (essential to any road), ridges and dips (country roads), cracks, grass infested cracks, etc. and then put some fine powder, pepper, very fine sand at the edges where the road joins the grassy verge or has a gutter in urban settings. And unless the road modelled is supposed to be freshly laid, the surface will have gone a mid grey at the darkest after a few days of traffic.
But make sure that paint is absolutely matt.