Signal control for speeding vehicle control, on major roads at night

The development of the motorized society in Japan has been remarkable in recent years as evidenced by the increasing number of vehicles, as well as the increasing number of persons with a driving license. At the same time, the number of fatalities due to traffic accidents has been increasing, which has is a major social problem. On the other hand, thanks to improvements in the vehicular traffic environment such as improved roadway surface conditions, wider road widths, an increase in the number of lanes, etc., motor vehicle travel has been made easier, which has contributed to the tendency to travel at higher than regulatory speeds. Furthermore, because there are fewer vehicles traveling at night than in daytime, it has become common practice for some vehicles to travel at higher speeds at night. Traffic accidents resulting from such high-speed travel are likely to lead to serious accidents such as those involving fatalities. Under such circumstances, with the aim of suppressing speeding, the Oita Prefectural Police HQ adopted a new signal control scheme for speeding vehicle control based on offset adjustment which has been used at night on major roads including Ohzai-Oitako Line, a prefectural road within Oita Prefecture. Thanks to this new signal control scheme, the Police HQ has produced favorable results in both speeding vehicle control and accident prevention.