When the expressways were operated only by metallic paired cables, deployment of the facilities such as traffic detectors or variable message signs had to be limited because of lack of the existing communication infrastructure. After the deployment of fiber optics, various facilities could easily be installed making Japanese expressways more intelligent, and made it possible to centralize the traffic control centers and the facilities control rooms contributing to the expressway operation efficiency. These fiber optics were deployed as joint ownership with a telephone company and were used for business phone use. Because of this joint ownership to share the cost, 5300km fiber network could be deployed throughout Japan, which means the expressway fiber network is utilized as a role of the national telecommunication infrastructure in Japan. The road telecommunication infrastructure is becoming very important in the world lately to support and enhance ITS. In this paper, the Japanese approach and experience of deploying fiber optics and sharing the cost with a telephone company are introduced and further discussion is made toward future fiber network systems to cope with future intelligent expressways.
Samenvatting