What size gravel works best for a driveway?
Driveway gravel is usually sized by the stone that is mixed with the sand.  Example: 3/8", 3/4" etc. A good driveway packing gravel is 3/4".  Another good choice is 3/8" stone dust. This material packs down very hard and smooth.

So when you call to order your material, ask for 3/4" packing gravel or 3/8" stone dust.