Disclosed is a traffic information system high in the ability to collect information. An on-vehicle apparatus is carried on a vehicle, to collect traffic information such as traffic jam information, accident information and weather information. The on-vehicle apparatus comprises a car navigation system, where position information is sensed, and information relating to a traffic jam, an accident and weather are manually entered or are automatically sensed. The on-vehicle apparatus further comprises a laser radar, where the number of vehicles, the speeds of vehicles, and the shapes of vehicles are sensed, and traffic jam information and accident information are created based thereon. Various information collected by the vehicle are transmitted to a center via a repeater. Information processed by the center are transmitted to vehicles again.