Bijogi junction duplexed traffic signal controller system

The connection of the Tokyo Metropolitan Expressway Route No. 5 (Ikebukuro Line) was connected to the Tokyo Outer Ring Expressway at the Bijogi junction and its limited use has continued thereafter. Also, following the extension of the Metropolitan Expressway Saitama Omiya Line to Yono City from the Bijogi junction, traffic lights were installed and put into service at the intersection of the link roads of this junction from May 18, 1998. Since this system is the first traffic signal control system in the expressways in Japan, various types of backup techniques were introduced in order to ensure safety and reliability. In this paper, we give an outline description of this traffic signal equipment, and describe the organization and functions of the duplexed traffic signal controller equipment which needs to be highly reliable, in order to achieve safe and smooth control of the traffic flow.