Asphalt usually uses pea gravel (1/4"-1/8") and chat (1/8" and dust) mixed in tar. It might make a more dust free top dressing over a base rock width layer of crushed rock 3"-5", followed by a 2"-3" layer of 1"-2" crushed rock that will lock into the base for great stability....A 1-1.5" layer of chat and pea rock will settle into the gaps of the larger stones and when done right, is nearly as smooth and solid as concrete under mild loads and low speeds.
