I have a long driveway of stone chips, approx. 1/2-2" diameter. (The original owner also put 6x6 railroad ties on either side to keep the rock from spreading into the lawn.) I also have a vacation home in central PA. with a steep half-circular drive way (steep slope up, level area in front, steep slope down) similar to what you are describing. The driveway is also covered in stone chips on the tire paths ONLY, with a grassy area in between. There is also some moss in the middle area which grows in the shady spots. Both these driveways are easy to maintain, and the stone packs down and holds together well, as long as it's not spread too deep. Grass and weeds WILL grow up in the stones, but the driveway in PA is so well-packed that I just mow it to maintain it in the summer. This driveway IS for a vacation home, so it doesn't get alot of heavy traffic, but it seems like it would hold up fine even under heavy use.
There is an access road into our little neighborhood that we all help $$ maintain, and my one neighbor does the work. We use "millings" to cover it, which is basically crumbled asphalt. It packs down very well, too, (better than stone chips) but tends to get potholes easily. IMO, I think it would be tough to spread it in two even strips; it probably wouldn't give it enough material to pack together well....
I have ordered both stone and stone dust from Tom Hance Co. in Prince Frederick; they are reasonably-priced and will deliver on short notice.
The bad thing about mulch/wood chips is that, unlike stone, they eventually decompose and need to be replaced. When the wood chips are wet, they are very slippery, and if you have a slope, they would probably get washed out in a heavy downpour.
I hope I've helped you some!
