Some popular types of gravel that work well to construct driveways include pea gravel, crushed stone, washed clean stone and washed crushed clean stone. Several layers of assorted sizes of gravel work best to build a solid, durable driveway.
The foundation of a quality driveway is best constructed with an even, compact 4-inch layer of large, angular crushed stone, or “clean stone," spread across the bottom of the trench. This base layer of large stones measuring 4 inches in diameter helps prevent drainage. The next layer should be 4 inches of slightly smaller angular stones. Lastly, a layer of small, nickel-sized stone gravel that includes fine and coarse rock dust is added to the top layer of the driveway. This small gravel settles well against and between the larger gravel, and the rock dust helps the pieces of gravel to better adhere together.