A communication system includes an information acquisition unit that acquires information (road information), a type identifying unit that identifies the type of the information acquired by the information acquisition unit, a storage unit (vehicle storage unit, server storage unit) that stores relationship information that associates the type of the information with the transmission direction of the information, and a direction identifying unit that identifies the transmission direction of the information acquired by the information acquisition unit based on the identification result by the type identifying unit and the relationship information stored in the storage unit (vehicle storage unit, server storage unit).