Ah yes, the urban hotspots of…Scotland?

I’d guess grift. The pic shows gravel beneath the asphalt in those potholes. For any major road, you should be having more asphalt than that. Ontario major series highways have large amounts - 200-350mm is standard, 400 I’ve seen in areas with constraints. From the pic, I’d guess youre at 1-2 lifts, so maybe 100mm, at most? Given the speed of deterioration, likely only 1 60mm lift.