I had a spot on my asphalt driveway that was obviously being pushed up by a
root (there was a seam between two sections where water could get in so that
wasn't surprising). The last couple of days I tackled it, chopping up the
asphalt and digging around the root.

I expected to find the usual shape for roots, getting bigger as it got
closer to the tree. Instead I found something very strange. There was a big
lumpy bundle of twisted roots, up to 4 inches in diameter in places. But
they didn't go anywhere. They just wrapped around themselves and disappeared
into the soil in various directions. The really strange thing was that all
the branches were quite small - no more than one inch.

It's almost as if the bundle wasn't attached to a tree at all, but I assume
that one of those little side shoots must lead to a tree. There's a mature
ponderosa pine about 12 feet away so I assume that must be it.

I didn't know that roots could take such a bizarre shape, and also I'm
wondering how to prevent this thing happening again. I presume some small
deep root must have come to the surface some years ago and started that
whole process. I don't want to dig up more of my driveway than necessary to
get every tiny little root. I'm wondering if simply digging a deeper hole
and filling it with gravel before repaving would prevent root growth by
drying the zone out. (There's gravely soil there now).