Introduction of congestion tail display system into Metropolitan Expressway

Nearly half the number of traffic accidents on Metropolitan Expressway were caused by rear-end collisions, most of which were attributable to congestion. Thus, as one measure to prevent such accidents, the Metropolitan Expressway Public Corporation (MEPC) installed information display boards on routes frequented by accidents to inform drivers of the tail position of congestion ahead and began operating a congestion tail display (CTD) system which provides drivers with real-time information on the momentarily changing tail position of congestion. This paper introduces the CTD system operating on the expressway and reports the results of our investigation on the accuracy of congestion tail information provided by the system