Lifting Sunken Concrete Driveway Pads

Why repair (1) Prevent possible injury from tripping, (2) stop the continued sinking and cracking of the concrete pads, and (3) improve the look of the driveway. I had tripped on the raised edge separating two concrete driveway pads while getting out of the car several times since we purchased this 40yearold house, and I was concerned for the safety of myself, my wife, our friends, visitors and elderly members of our family (my father is 93). The options (1) remove and replace the sunken and cracked