In the VICS (Vehicle Information and Communication System), which began operation in 1996, the ITS (Intelligent Transport Systems) was the first system for which R&D was conducted and the first system to produce results. The key infrastructure of this system is the infrared beacons installed along the roads. The infrared beacon has the function of two-way communication in addition to the detecting function of conventional vehicle detectors and can accurately grasp motions of individual vehicles by using the former function. And various infrared beacon systems have been widely used for giving priority to public vehicles, for vehicle control and for emergency vehicle support. Especially, for the VICS, that provides traffic information from infrared beacons to vehicle drivers, the number of on-vehicle units responding to infrared beacon has increased to 320,000 in only four years. On the other hand, 24,000 infrared beacons have been installed so far all over the nation, and the number will be intentionally increased. To achieve an advanced traffic control system in the 21st century, more in-vehicle units will need to be installed, the number of infrared beacons expanded, and preparations made to qualitatively improve the system. The Agency has made efforts to collect more up-link information from on-vehicle units through the infrared beacons in order to promote improvement of the traffic control system. This paper reports the issues that need to be addressed to achieve such a system and the current state of progress.
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