A traffic information creating device for a navigation system, comprising: a travel information acquisition unit that acquires travel information including a current location of a vehicle and a vehicle speed of the vehicle at unit time intervals; a map information storage unit that stores map information including link information related to links that constitute a road; a traffic information acquisition unit that acquires traffic information, which includes a distributed traffic congestion level of each link and which is distributed from a device outside the vehicle at predetermined time intervals; a link exit determination unit that determines whether the vehicle has exited a link on the basis of the map information; a travel traffic congestion level acquisition unit that, when it is determined that the vehicle has exited a link, acquires a travel traffic congestion level of the exited link on the basis of the travel information within the exited link; a coincidence determination unit that determines whether the travel traffic congestion level of the exited link coincides with the distributed traffic congestion level at the time point at which the vehicle has exited the link; characterized by: an update determination unit that, when it is determined through the coincidence determination unit that the travel traffic congestion level of the exited link does not coincide with the distributed traffic congestion level at the time point at which the vehicle has exited the link, determines whether the traffic information has been updated and the distributed traffic congestion level has been changed within the exited link; a distribution time rate acquisition unit that, when it is determined through the update determination unit that the traffic information has been updated and the distributed traffic congestion level has been changed within the exited link, acquires a distribution time rate of each distributed traffic congestion level within the exited link; a traffic congestion level determination unit that determines a traffic congestion level of the exited link on the basis of the distribution time rate of each distributed traffic congestion level, acquired through the distribution time rate acquisition unit, and the travel traffic congestion level of the exited link; and a traffic congestion level storage unit that stores the traffic congestion level of the exited link, determined by the traffic congestion level determination unit, in association with the exited link. a travel information acquisition unit that acquires travel information including a current location of a vehicle and a vehicle speed of the vehicle at unit time intervals; a map information storage unit that stores map information including link information related to links that constitute a road; a traffic information acquisition unit that acquires traffic information, which includes a distributed traffic congestion level of each link and which is distributed from a device outside the vehicle at predetermined time intervals; a link exit determination unit that determines whether the vehicle has exited a link on the basis of the map information; a travel traffic congestion level acquisition unit that, when it is determined that the vehicle has exited a link, acquires a travel traffic congestion level of the exited link on the basis of the travel information within the exited link; a coincidence determination unit that determines whether the travel traffic congestion level of the exited link coincides with the distributed traffic congestion level at the time point at which the vehicle has exited the link; an update determination unit that, when it is determined through the coincidence determination unit that the travel traffic congestion level of the exited link does not coincide with the distributed traffic congestion level at the time point at which the vehicle has exited the link, determines whether the traffic information has been updated and the distributed traffic congestion level has been changed within the exited link; a distribution time rate acquisition unit that, when it is determined through the update determination unit that the traffic information has been updated and the distributed traffic congestion level has been changed within the exited link, acquires a distribution time rate of each distributed traffic congestion level within the exited link; a traffic congestion level determination unit that determines a traffic congestion level of the exited link on the basis of the distribution time rate of each distributed traffic congestion level, acquired through the distribution time rate acquisition unit, and the travel traffic congestion level of the exited link; and a traffic congestion level storage unit that stores the traffic congestion level of the exited link, determined by the traffic congestion level determination unit, in association with the exited link.