Sam, just a couple of observations. By looking at your photo's the grading work with the shale looks like it turned out good. It looks to be graded so that it will drain and keep your road high enough to keep it dry. I think there are a couple of reasons that when you attemped to drive in after a rain that you were leaving ruts. The shale needed to be "rolled in" either with a flat drum roller or "wheel rolled" with one of the trucks that were delivering the stone. That would have compacted the shale and sealed it from moisture. The other thing is it looks like you went with a straight stone product and not a "crusher run" stone. The straight stone will let moisture down into the subgrade and soften it, as you have already found out. You will also see that the straight stone will tend to push down into your subgrade. Thats why I like to go with all crusher run. It will spread out the weight and not sink into the subgrade. The grade was probably fine until you got the rain. For now stay off of it. Any ruts you leave will hold more water and just mess up your grade making the problem worse. Once things dry out top the stone you have down now off with crusher run. One question. Why are you going so wide with the stone? One truck wide on a private drive is plenty. The stone will tend to widen out anyway after it gets some traffic on it. Not all is lost, so don't worry. It will eventually tighten up and be okay if you get it topped off with some crusher run. The main thing now is to stay off of it! Don't make it worse by rutting it up just because you want to drive in on your new road. One other point. The stone needs to be at least 6 inches in depth, otherwise it just won't hold up. At $240 per load for the stone..............that's a steal, it's twice that here.
Sincerely, Dirt