Traffic Regulation Technology by Movable Barriers

Approximately a half century has passed since the construction of expressways in Japan, and expressways have become decrepit over the decades. In order to ensure safety and security of expressways for the next generation, expressway companies have been carrying out large-scale renewal works of bridges and tunnels (hereinafter collectively the "renewal works" and individually a "renewal work"). Because renewal works are carried out while vehicles pass by the side of work zones, various types of safety equipment have been used to regulate traffic lanes such as rubber road cones, more rigid temporary barriers and so forth. However, speeds of passing vehicles are fast and, if a vehicle accidentally enters a work zone, rubber road cones cannot prevent from a vehicle entry which endangers workers' lives. Therefore, East Nippon Expressway Company Limited (hereinafter "NEXCO EAST") group adopted traffic regulation technology by movable barriers, the Road Zipper System (hereinafter "the RZS"), for renewal works. Using the RZS is aimed at improving workers' safety by prevention of accidental vehicle entries and alleviating traffic congestion by more efficient traffic regulation. This paper examines effects of the RZS introduction, enhancement of safety and prevention of traffic congestion associated with the use of the RZS in traffic regulations and lane reconfigurations according to the time of day, as well as future developments.