I'm not an expert by any means but will relay what 40+ years of farming experience building various roads to fields and bins has taught me.

So much depends on what you have to start with. In our case we have a foot (give or take) of topsoil over impervious clay.

Another thing that is important is what kind of traffic is expected on the road.

For a narrow small road to our pond that mostly a Polaris 4 wheeler drives on, I just scattered some AB3 (inch crushed calcium rock with all size fines left in it).

Where we have heavy semi truck traffic going to and from our bins we srtip off all the topsoil down to clay, add a layer of 4-6" diameter rock with fines, then 2" cleaned lateral rock (like used for septic system drain fields), then top with AB3. We end up with about a foot total of rock. That is in our most sever traffic areas where heavy trucks are traveling repeatedly year round.

Other roads with various loads and seasonal use get something in between those two extremes. For a road that pickups travel on mostly we might just put down 2" cleaned lateral rock, then AB3 on top. The bigger rock keeps the finer stuff from disappearing into the topsoil.

If it is in a flat area with runoff we might make ditches on each side to keep the water away. If there is natural drainage just make sure the gravel either is above surrounding soil or flat so the water will run off and not pond.

If you have mostly rock to begin with underneath, or if your traffic load will be light, not nearly so much might need to be done.

"Around here" if we just put gravel or AB3 on top of the topsoil, it will quickly disappear into the soil if there is any kind of traffic with any kind of weight traveling over it. Go SE of here into the Ozarks, and they are mostly rock underneath and they have to do a minimal amount of topdressing to make their roads sound.

So it all "depends" on what you have to start with and what you will be driving over the top.

John

I subscribe to Pond Boss Magazine