MOBILE OBJECT COMMUNICATION APPARATUS

PROBLEM TO BE SOLVED: To efficiently obtain necessary situation information on another mobile object even if a plurality of mobile objects exist around a mobile object itself by changing the frequency of an information signal transmission in accordance with situation data. SOLUTION: A transmission information judgment part 9 fetches the distance to a crossing, arrival time to the crossing and a travel road type from a position situation judgment part 3, fetches the speed and course/travel state of the self- vehicle from a vehicle driving situation judgment part 5 and fetches a self- vehicle order in a vehicle group, a vehicle group scale, a response request and communication frequency per unit time from a peripheral situation judgment part 7. A transmission information judgment part 9 sets an evaluation point of every information unit, reads a weighting coefficient of every information unit from an inner memory and calculates self-vehicle information transmission frequency. Since transmission frequency is decided by adding weighted results for respective situations, a mobile object and transmission frequency fitted to the peripheral situation can precisely be obtained.