Any reason why this is? Scuffing against the curb is all I can think of.
At least in Virginia, the part of the road closest to the ditch deteriorates the quickest, because most 2-lane roads in the state have no shoulders and drainage ditches within a foot of the pavement. And the constant wetness seems to cause the pavement to give up quickly. I've seen where they'll put new asphalt down in a strip 4 feet wide on each edge of the pavement, because that's all deteriorated and the middle of the road is fine.
Apparently, continually repaving and fixing potholes is cheaper than fixing the drainage.