There's all sorts of clay out there and your might be totally different than mine. I have three diferent colors on my place. Two are really good for roads, one is terrible.
I've found that you have to get it dry, or near dry to work with it. If you got a moisture issue, than it's not the clay,but drainage. When you got good drainage, the water runs right off the clay and it dries faster than loam or any other soil.
I've had wet spots take months to dry out enough to work with. It will never hold any weight until it's dry. Than you can build it up and know that it will last forever!!
Of course, you still want gravel over it, but that's just for a solid surface when it's wet out.
I've learned that you do this, and clay is a wonderful material to work with!!!
Eddie