Gravel can never be compacted. It settles in place when rolled or viberated. Example, if you were to apply 3 inches of gravel on your driveway roll it viberate or what ever and when you were done you could give the gravel a kick with your foot and it would be loose.
When I was sent out to grade a dirt road full of pot holes, I would always cut the road down to the bottom of the potholes, providing there was decent material to do so and regrade the entire road.
The material you want to use is called 2A