Driveways are one of our specialties, but we do them right !! The first thing we do is remove the existing concrete and haul it away. (If its an existing removal and replacement). Then we inspect the dirt grade for problems that would cause harm to your new concrete driveway and address any problems such as roots or cavities and fix them. then, we always place a crushed concrete or bank sand subgrade. Then we compact the subgrade with a plate compactor prior to adding the reinforcement. We install dowels into all abutting concrete to prevent settling of the new concrete against the existing. We use number three rebar which is 3/8 of an inch. After rebar installation, we place the concrete, then install engineer depressed joints prior to the finish. we do not use wood. Wood rots out after a couple years which creates two problems for you. one, it allows water to get under your concrete. And two, it reduces the cosmetic value of the driveway. (Just looks bad!) all the driveways pictured below, even the decorative ones --do not have wood as a control joint.
(Unless wood joints are requested by the owner)