Information processor

An information processor comprising:

• a communication unit having a transmitter and a receiver;
• a memory;
• and
• a processor that, in a case of receiving route information of a scheduled route on which a vehicle is scheduled to travel, makes the memory store the received route information of the scheduled route, and
• in a case of receiving route information of a searched route searched by an in-vehicle device loaded in the vehicle, generates reference information regarding congestion of the searched route based on the route information of the scheduled route and transmit the generated reference information to the in-vehicle device,
• wherein the processor detects the number of scheduled routes for which traveling through a section included in the searched route is scheduled, and
• determines whether or not congestion occurrence in the section is predicted, based on the detected number of the scheduled routes and a weighting factor indicating easiness of route change of the scheduled routes.