Rockfall prediction system

At Honzon-iwa where the terrain is steep, on National Highway No. 49 is exposed to the risk of rockfall and slope failure. The rock fall in 1995 due to the Northern Niigata Earthquake disrupted the traffic on the highway and the rehabilitation works took about three months. A detailed study by acommittee of specialists revealed that several minor rockfalls occurred prior to a major rockfall.

In response, the Niigata National Highway Work Office of the Ministry of Land, Infrastructure and Transport has developed a Rockfall Prediction System in which sensors monitor the pre monitory phenomena of minor and major rockfalls and transmit them to the information control room. Being an unmanned remote control round-the-clock monitoring system, this system sends the detected information to on-site administration offices and road message signs simultaneously, allowing swift actions to betaken and improving the reliability of the highway.

Previously, when noticeable tremors occurred, prolonged traffic restrictions were necessary for various inspections. Since the new rockfall detection system can continuously monitor changes in rockfall-prone slopes and detect even minor rockfalls, prompt warnings can be issued to drivers and traffic restrictions imposed. In addition, displaying warning information on message signs allows drivers to make a detour earlier, reducing time and drive losses.

[Niigata National Highway Work Office of the Hokuriku Regional Development Bureau, Ministry of Land, Infrastructure and Transport]