A vehicle information processing device which specifies a traveling road of a host vehicle, comprising: a host vehicle information obtaining unit configured to obtain host vehicle information including current position information of the host vehicle using a GPS; a road information obtaining unit configured to obtain road information, the road information including a plurality of nodes which denote position information of a plurality of locations on a road, and links which connect the nodes to each other; a surrounding roads extracting unit configured to extract surrounding roads which are roads surrounding the current position of the host vehicle and on which the host vehicle may be traveling using the host vehicle information and the road information; a traveling road selecting unit configured to temporarily select a traveling road of the host vehicle using the host vehicle information, and the road information on the surrounding roads; a reliability determining unit configured to determine reliability of a temporary selection result of the traveling road selecting unit using a plurality of pieces of reference information including a GPS precision, the number of surrounding roads, and a relationship between the host vehicle information and the road information of the surrounding roads; and a traveling road specifying unit configured to specify a traveling road of the host vehicle using the reliability, and the temporary selection result of the traveling road selecting unit, characterized in that the road information obtaining unit is configured to obtain the road information from an information transmission device which is installed in a road and not from map data in an in-vehicle storage unit; and the plurality of pieces of reference information include the difference between a distance to the closest surrounding road and a distance to the next closest surrounding road as the relationship between the host vehicle information and the road information of the surrounding roads. a host vehicle information obtaining unit configured to obtain host vehicle information including current position information of the host vehicle using a GPS; a road information obtaining unit configured to obtain road information, the road information including a plurality of nodes which denote position information of a plurality of locations on a road, and links which connect the nodes to each other; a surrounding roads extracting unit configured to extract surrounding roads which are roads surrounding the current position of the host vehicle and on which the host vehicle may be traveling using the host vehicle information and the road information; a traveling road selecting unit configured to temporarily select a traveling road of the host vehicle using the host vehicle information, and the road information on the surrounding roads; a reliability determining unit configured to determine reliability of a temporary selection result of the traveling road selecting unit using a plurality of pieces of reference information including a GPS precision, the number of surrounding roads, and a relationship between the host vehicle information and the road information of the surrounding roads; and a traveling road specifying unit configured to specify a traveling road of the host vehicle using the reliability, and the temporary selection result of the traveling road selecting unit,