During a home inspection in Grand Blanc, I came across this driveway. This issue is certainly not unique to just that area. I see this at almost any home I inspect that is over a few years old. The driveway has cracks, is sagging, lifting, separating etc... and it's all from the same culprit, water. Once water has a way to get under the driveway, it moves the soil all around from under the concrete, this can cause erosion under the concrete pads. Without the proper support for the concrete, it can shift causing cracking. This in turn allows more water to get under the driveway and the cycle continues and so do the issues. Sealing these cracks is how you prevent further deterioration and if you can seal them as soon as the cracks appear your even farther ahead of the game.
Here is a good video to check out that shows the process on how to fix driveway cracks.