Since 1996, VICS has been deployed quickly throughout Japan. The goal of VICS is to provide real-time traffic information to drivers in order to give them decision-making evidence.
The raw traffic sensor data are processed so that the car navigation system can interpret them. Each raw traffic datum is aggregated onto a standard digital road map database called the VICS link. Travel time is estimated from spot velocity data by ultrasonic sensor and infrared sensor, which are optimally mapped onto VICS links. On the other hand, if travel time itself has been acquired, it is divided and
mapped onto the VICS link. Figure 10.1 shows the priority in which the sensor data are used. In Europe and in the United States, so-called RDS-TMC (radio data service, traffic message channel), transport protocol exports group (TPEG), and or the like has been deployed. Major differences are the kinds of media on which the information is broadcast.