I need to build a driveway that will be 500+ feet long. This long stretch only needs to be a single driving lane to get from the road back to the house at which point I can use the methods used in the projects. My thought of approach will be to clear a stretch with 12 feet wide of clearance. The minimum width from inside of the tires on my car is 4 feet. A dump truck has an axle width of 8 feet. I would like to just dig 2 trenches 4 feet appart and being 2.5 feet wide. The trench driving lane then would cover wheel width from 6 to 9 feet. My soil consists of clay with about a foot of topsoil on top. The driveway will run next to a low area and most of it will have a good natural grade sloping in that direction. I have 2 spots where water will stand after a heavy rain and early spring so I can cut across the trenches with a gravel bed to help drain this.
I'm wondering about the depth to dig the trenches? I was thinking 3 feet and filling with crushed rock until I found out the price of crushed rock in our area. Quality gravel is also a rare item in our area. I can gather a lot of field stone and other large rocks to throw in the trenches and then cover with 3-6 inches of crushed rock. Will frost affect this in pushing up the large rocks? I have been driving on the top soil for the last 2 years during the summer (it's been very dry here) and there has been minimal impact.