I just put in a 60x12 driveway addition and extended my parking pad another 15x50 ft. The local aggregates dealer recommended 2" down limestone. I drove over it a bunch, thinking it was well packed. A week of regular rain, and big ruts are present when driving my 3/4 ton Dodge over it. I'll have to regrade it and rent a compacter. The dealer recommended waiting till fall or even till next summer, then top with 3/4" down limestone. Our driveway is 3 years old, put in by a contractor with a track dozer, also 2" down base, but 3/4 clean top. Hasn't sunk an inch. Only now are tire tracks visible needing an inch of more 3/4 clean.