The sinkhole question reminded me of what I had done to my "sinking driveway".
A large portion of my concrete driveway got a crack which allowed water to get underneath and form a void, which in turn caused that part of the driveway to lean and make an even bigger crack for water to enter. I hired a company that drilled holes in the concrete and pumped cement (under pressure) underneath the leaning portion to raise it back to level as it filled the voids. It cost me about $400 which was much better than replacing a whole driveway. This process can even level a house or a bridge - absolutely amazing!