Ask around and you'll hear that a concrete driveway should be four inches thick. That's true for a sedan on a perfect base in mild soil. It's not the whole story for a Permian Basin driveway that sees a lifted pickup, a gooseneck trailer, or a delivery truck backing up to the garage.
For most Midland and Odessa homes we recommend five inches for the driveway itself and six inches where trailers park or trucks turn. The extra inch costs a little more in concrete and saves the whole slab when a heavy load parks in the same spot every day.
Thickness only works when the base under it is right. Our soils shift between wet and bone-dry, so we compact a crushed base under every driveway and put reinforcement on chairs so it sits in the middle of the slab, not on the dirt where it does nothing.
Control joints are the last piece. Concrete is going to crack; the question is whether it cracks along a straight line we cut on purpose or wherever it wants. We cut joints on a grid sized to the slab thickness, within the first day, before the slab decides for itself.
If you're replacing a cracked driveway, the fix is almost never a thicker slab alone. It's base, steel, thickness, and joints working together. That's what goes into every written estimate we send.