If we talk about small neat holes (about 10 cm in diameter) that appear soon after road repair (usually 4-5 pieces each), then these are traces of asphalt samples to study its quality and compliance with building codes. In theory, the supervisory authority should take such samples from randomly selected parts of the roadway, but in practice, the contractor's foreman, who is in charge of repairs, "prompts" the inspector where it is better to take these samples. And everyone is happy with each other.
Rather, heaps of money that were rolled up there, rather than corpses. If you count all the holes along the country's roads, then the population of China will not be enough to make this assumption even a little bit like the truth