Center-side system and vehicle-side system

The purpose of the present invention is to provide a technology that enables the reliability of a probe information system to be enhanced. A center-side system (201) is provided with a center-side receiving unit (231) that receives, from a vehicle-side system (101), probe vehicle position information, drive type information and probe vehicle speed information. The center-side system (201) is further provided with: a traffic condition estimation unit (217) that estimates traffic conditions, including the speed at which a drive type can travel, on the basis of the probe vehicle position information, drive type information and probe vehicle speed information received by the center-side receiving unit (231); and a center-side transmission unit (232) that externally transmits the traffic conditions estimated by the traffic condition estimation unit (217).