The tar-and-chippings thing does serve some purpose: it makes roads grippier - at least for wide, flat car tyres. As tarmac wears out, the surface becomes polished and slippery.
It's no fun to ride on though.
A few years back now, our council put up a temporary sign announcing a temporary road surface. It wasn't temporary, it was knackered then and with no work it's still knackered now. The sign got buried in the vegetation on the verge. In the second summer after it was put there, a farmer tore it to bits with his flail mower as he cut the verge: he couldn't see it. The wreckage is still there, and so are most of the potholes.