Beneath the pavement: what German city streets look like when exposed

(Giggle) This sounds like some sort of investigative reporting piece. Alas, I am not that advanced; I'm just nosy.

Have you ever wondered what German streets look like below the street level? There is road construction throughout town now so of course I had to check it out (and take a picture). I had heard that German roads (and especially the Autobahn) are really deep. Indeed, it looks as if the top layer is at least 8 inches deep (by my rough estimate, eyeballing it). There is even a layer below that. I'm too lazy to look up how deep the pavement goes, but it's deeper than it tends to be in the States.

In my home state, Michigan, even though we get a lot more freezing and thawing than my little corner of Germany does, the depth of our paved roads is horribly pitiful compared to German roads. Perhaps that's why we have to repair them so often? Maybe Michigan should invest in higher quality roads with fewer repairs. Or, we just need to wait for winter and enough snow to fill in the potholes, I guess.