A method and apparatus for operating compacting machinery such as landfill, earth or asphalt compactors relative to a work site to compact the site material toward a desired degree of compaction. A first model (420) representing the desired degree of compaction of the site (12) and a second model (430) representing the actual degree of compaction of the site (12) are stored in a digital data storage facility (126). The machine (10) is equipped with a position receiver to determine in three-dimensional space the location of the compacting portions of the machine (10) relative to the site (12). A dynamic database (124) receives the machine positon information, determines the difference between the degree of compaction of the first and second site models (420, 430) and generates representational signals of that difference for directing the operation of the machine (10) to bring the actual degree of compaction of the site (12) into conformity with the desired degree of compaction. In one embodiment, the signals representing the machine position and the difference between the first and second site models (420, 430) are used to generate an operator display (22) which is updated in real time as the machine (10) operates over the site (12). Alternately, the signals representing the difference between the first and second site models (420, 430) can be supplied to automatic machine controls for automatic or semi-automatic operation of the machine (10).