The road

Also, sand is known for its ability to drain off water and for its load bearing capacity, plus obviously it's not organic like topsoil and won't decay and settle over time. It's usually viewed as a desirable fill material for backfilling pipes or as a sugbgrade under slabs and footings. The only caveat is that it has to be contained, like inside of a footing, or under a slab. Otherwise it can shift on you and/or be easily washed away from rain. Is there anyway to get topsoil or claylike materials to shore up the sides of the road? If you did that you could contain the sand and keep it from shifting and eroding away. Then, if you installed a decent amount of drain tile (perforated drain pipe) wrapped in filter cloth under the road so that any water that percolates down into the sand will be drained off, then I would think that would make it stable. And if you sealed the top of it with clay and then put stone on top of that, then I would think that would hold up ok. Of course if the guy who put the road in didn't remove the topsoil and organic material under all the sand, that material will decay and settle over time; which will cause the rest of the road to settle in a similar fashion.