Traffic Control System Providing for Large-Scale Disaster

The Traffic Control System of the Metropolitan Police Department (MPD) is designed to create a safe and comfortable road traffic environment by controlling traffic signals in approximately 8,000 locations (as of 2013) throughout the Metropolitan Area, based on traffic information collected through vehicle detectors and other devices. However, the East Japan Earthquake that occurred in March 2011 and brought about immense damage mainly to the northeast of Japan, caused full suspension of all transportation system except for general roads in Tokyo (located approximately 375km off the epicenter of the earthquake), resulting in long-term congestion with people and vehicles jamming the streets. (Figure 1.) In a large-scale disaster situation, where securing emergency traffic routes for search and rescue and avoidance of massive congestion is essential, the role of the Traffic Control System is huge. Since an earthquake is expected to occur directly beneath the Tokyo Metropolitan Area in the future and building on these lessons learned in the Great East Japan Earthquake, the MPD is promoting various efforts to realize the full potential of the Traffic Control System even under a large-scale disaster situation. This paper introduces some of these activities.