Patent ID: 8583362

Claim:
A road-information generating apparatus for providing road-selection information to a navigation apparatus of at least one road-selection information receiving vehicle, comprising: a history-information generating section which obtains probe information transmitted from a respective navigation apparatus mounted in at least one probe information-transmitting vehicle, which correlates the obtained probe information with links defined by map information stored in a storage medium to generate history information indicating history of vehicle travel on a road, and which accumulates and stores the generated history information to obtain accumulated and stored history information; a traffic-volume-information obtaining section which obtains traffic-volume information indicating a traffic volume on each road included in a zone preset on a map for which the amount of the accumulated and stored history information exceeds a predetermined amount, wherein said traffic volume is a number of vehicles on the road per unit time; a road-selection-information generating section which takes into account the traffic volume on each said road included in the zone for which the amount of the accumulated and stored history information exceeds the predetermined amount to generate road-selection information for avoiding at least one of the roads included in said zone for which the amount of the accumulated and stored history information exceeds the predetermined amount and that is ahead of the at least one road-selection information receiving vehicle, said generating section indicating difficulty of passage when the obtained traffic volume on the at least one of the roads included in said zone for which the amount of the accumulated and stored history information exceeds the predetermined amount and that is ahead of the at least one road-selection information receiving vehicle during a predetermined period is smaller than a predetermined reference value, taking into account the traffic-volume information for other roads in said zone for which the amount of the accumulated and stored history information exceeds the predetermined amount; and a communication unit which receives the probe information transmitted from the navigation apparatus mounted in the at least one probe information transmitting vehicle, and which transmits the road-selection information to the navigation apparatus of the at least one road-selection information receiving vehicle.