An area corresponding to a zone 15 on a road 14 is divided to area A and area B, and an information traffic volume in each area is monitored. When overflow is about to occur, time slots for other areas are temporally allocated to the area to evade the overflow, so that shortage of communication channels due to a traffic jam or for some other reasons can be prevented in a system for providing automated driving controls for vehicles by means of communication systems based on a zone system.