How to Fix a Sinking Driveway: Add additional layers of cold patch to fix the sunken area of driveway. http://www.familyhandyman.com/smart-homeowner/diy-home-improvement/how-to-fix-a-sinking-driveway/view-all
Constant sun exposure will wear away the oils in your asphalt, and freezing and refreezing during winter causes cracks. To combat these elements, it’s important to fill cracks and reseal your driveway every 1-3 years. If you live in an area that sees extremely cold winters or hot summers, it’s best to reseal every year. That way, coming home won’t start to feel like an off-road excursion.