An apparatus and method for directing the operations of multiple geography-altering machines on a common work site relative to one another. Position information from several machines is shared to generate a common, dynamically-updated site database showing the machines' relative positions and site progress in real time. The common site database is used to direct the operation of one machine with respect to another machine or machines, for example by generating an operator display of the site showing relative machine position and total machine work on the site. The operator can accordingly adjust the machine's operation to avoid interference with other machines or unnecessary overlap of work on the site. The information can also be used to coordinate the operations of several machines in complementary fashion. Machine position information can be broadcast from the machines to the site database to create a common, dynamically-updated database which is then shared with one or more of the machines. In a particular embodiment each machine is provided with its own dynamically-updated database and operator display, and machine position information is shared on a continuous, real-time basis between the machines so that they effectively share a common site database.