[Ed Fitzgerald]

Rich, your driveway has lots of fines in the mixture that is why it is compacted so well. If you have all the gravel the same size it is what we call "clean stone". It is excellent for drainage but terrible for compaction. Think of taking a beer mug and putting marbles in it. No matter how you shake it or arrange it once the mug is full you can not get another marble in. Turn the mug upside down and out comes all the marbles which leads to another fact "clean stone" does not need to be compacted unlike like crushed gravel.Gravel dumps out of the truck at about 85% compaction...think of a mason jar and you fill it with sugar if you thump it a few times on the counter you can get another spoonful or two into the jar,,but thats it so for argument sake the jar was 85% or so full. You say they usually put the gravel down just before a big rain. The reason for this is the water helps to suspend the gravel chips and centrifuge it into its' tightest configuration. If you go to the beach and drive on the beach along the waters edge you can relatively easily. However if you try to drive on the dunes what happens? It is the same sand but of a different moisture content. Ed