Doesn't matter the length of the driveway, if you can drive on it, then just drive on it. Cinder will smooth it out. If you are planning on pouring a concrete driveway, then there would be more considerations.
Obsessively digging out all of the jungle-muck on your proposed driveway route, in a hand-cleared ohia forest scenario, and then ordering a truckfull of 3/4" or 1 1/2" drain gravel ("washed" or whatever they call it), is something you will never regret. Putting gravel or base-course on top of any significant amount of said muck is a recipe for continual muck reappearance. The drainage to be had by initially getting completely down to the pahoehoe will give you drainage that is.. priceless.
Sounds like Darren has personal experience to back up his advice. How long did it take ya to hand-clear yours, D? (Changing poopy diapers must be a walk in the park for ya now.
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I had a short section of my driveway that was a bit over a foot deep of muck. The cinder truck drivers were sinking way in, and refused to go in unless I corrected it. I removed nothing, and added 3" gravel (not 3" minus)sprinkled on top, maybe 8 inches thick. These big bony pieces sunk into the mud when the trucks went over it and locked it up. Now it is solid and good, years later. Not gooey at all.
The rest of my driveway is red cinder. "Pit run" which means unsifted. The whole thing was rolled by a D9. It came out very nice. Better than the road I live on, but definitely not the best. Gravel is way better, but too expensive for me. Even well-packed red cinder erodes and makes gullies on steep parts. In retrospect, I wish I had spent more money on dozer time to smooth out the steep parts.
Yes, the fat stash of drain gravel probably set up some nice drainage to wash through the muck. Still, the common theme is bigger drain gravel below. Then you can go smaller to arrive at barefoot friendly "pea gravel" or whatnot to top it off. (Also, I was fortunate to have a way flat driveway-route opportunity. And that came about by contemplating, and bivwacking, observing, and not letting zeal cause me to arbitrarily set off on a less appropriate driveway route.)
Tim, that little shovel-fest to get the 70 or so feet scratched clean took about 3 months of fairly consistent digging -- like the proverbial ditch digging -- 'cept way more fun. Then again, that was about ten years ago and I was way keen and idealistic -- maybe even naive. I remember stumbling through yellow ginger, thinking, "Holy cow, yellow ginger.., better be careful not to damage it.."
..Now it's just, "Is that Digiorno's ready? No? Oh well, better just drink some beer from 5000 miles away.. <belch!> Nah -- I kid. We all kid..
A D-9 ripped mine. Now it is grapefruit sized rocks that are a bit hard to walk on and bumpy to drive on but it is navigable and dry. I tried to dig a hole in the ripped driveway area for a gate post and only got down about 8" before I hit solid pahoehoe. I only had a couple of inches of soil to begin with. I think it washed down between the rocks. Anyway there are only a couple of puddles here and there when it rains hard, so the drainage is excellent. The next step for me is getting some small stone spread.
