Inter-vehicle communication device

An inter-vehicle communication device mounted in a multiple of vehicles including an own vehicle and a peripheral vehicle and carrying out wireless communication between the own vehicle and the peripheral vehicle, the inter-vehicle communication device comprising:

• a position detector that detects a current position and a direction of travel of the own vehicle;
• a transmitting device that transmits own vehicle travelling information including the current position and the direction of travel of the own vehicle output by the position detector to the peripheral vehicle;
• a receiving device that receives peripheral vehicle travelling information including a current position and a direction of travel of the peripheral vehicle;
• and
• a processing circuit having a transmission output correction table in which a transmission power value or a corrected transmission power value in accordance with propagation characteristics of radio waves transmitted from the own vehicle is set to correspond to a region with coordinates having the direction of travel of the own vehicle as an axis, wherein
• the processing circuit to obtain relative position coordinates of the peripheral vehicle among coordinates having the direction of travel of the own vehicle as an axis, based on the own vehicle travelling information and the peripheral vehicle travelling information, to record the relative position coordinates, to acquire a transmission power value or a corrected transmission power value corresponding to the relative position coordinates from the transmission output correction table, and to determine transmission power for when transmitting the own vehicle travelling information to the peripheral vehicle.