Navigation systems, methods, and programs store traffic information and
crated prediction traffic information based on the stored traffic
information. The systems, methods, and programs search a plurality of
routes to a destination, each route including at least one link and
calculate a predicted passage time of each link in each route. The
systems, methods, and programs obtain, for each link, prediction traffic
information at the predicted passage time, based on the created
prediction traffic information and extract the obtained prediction
traffic information pertinent to route-search-as information to be
distributed, according to a predetermined order of priority.