I'm replacing an asphalt driveway with concrete with my neighbor's help. I've included a picture of the driveway. So far we've removed the old material and excavated the area. The "problem" begins with the subbase. I'm thinking we need a 3-4" compacted gravel subbase; my neighbor says the hardpan is compacted enough and being in Seattle area, the ground doesn't shift enough to warrant the cost of a subbase. I'm also thinking about a 4" 5.5 - 6 sack cement mixture with 1/2 " rebar but it was suggested to use the fiber cement mix instead. Also heard the fiber mix can irritate skin if walked on (or working under the truck) My neighbor is a great guy, but old school when it comes to projects. Am I on the right track or over doing it? I would appreciate some input from you seasoned guys.