On Tuesday, 11 February 2020 01:56:01 UTC, williamwright wrote:
I have a section of driveway that has a surface made of limestone that's
about a foot deep. It's OK and good enough except that part of it is on
a one in eight slope and when we have a downpour the finer bits of stone
get washed down the hill. I think the only solution is a proper surface,
but what? It is purely a utility area so appearance doesn't matter.
I don't want to spend a mint on this. The area I would do is ten foot
wide by about seventy feet long. Asphalt or what?
I wish my dad was still alive. He was in the road surfacing game in
supervisory roles for the last half of his working life. he'd know what
to do.

Bill

I assume you're going to DIY,in which case concrete is your best bet.
For utility, you only need do the sloping bit or even two parallel strips where the wheels run.
You need to think if trucks use it, there may be a need for reinforcing steel. Almost invariably the case. It only takes one truck to wreck it.

Sloping gravel roads need barriers at intervals and side ditches to direct the water off the road and convey it away.

The barriers can be a simple tump across the road at 45deg
They need regular attention as wheels wear them away and fine material piles up behind them.

You also need to avoid "tramlining" by driving allover a gravel road to equalise out the wear. (Water runs down the tramlines.)