As some suggested - regrade so water drains to outsides edges/ditches then add 1 1/2 inch crushed washed rock and drive on it. In the spring, all gravel is pretty much soft like that. What makes it hold loads/wheels is the thickness structure of road bed and enough drainage to push/drain water off to the sides into a ditch. In the case of your "outlot", I would simply regrade so water drains to outside edges, add inch and a half wash crushed rock and keep driving on it. Crushed rock so it inter-locks with itself. It'll give you the support to keep the water away. Washed, cause you don't need fines right now. After a couple years, you'll get fines in there and it'll seal the top and water will drain better . . . .