Patent attributes
Camera image information includes an image that is imaged by a camera installed on a vehicle. Lamp pattern information, which is information on a traffic signal having plural lamp parts, indicates a relative positional relationship between the plural lamp parts and an appearance of each lamp part when lighted. A system detects a subject traffic signal around the the vehicle based on the camera image information to acquire traffic signal detection information that indicates at least an appearance of each of plural detected parts of the subject traffic signal. The system compares the traffic signal detection information with the lamp pattern information. The system recognizes a lighting state of the plural lamp parts that is consistent with the appearance of each of the plural detected parts of the subject traffic signal as a lighting state of the subject traffic signal.