Challenges and Innovations in Advance Traffic Control System Under Extreme Weather Events

Japan has implemented an advance traffic control system to mitigate disasters caused by landslides and falling rocks during extreme weather events since 1950s. This distinctive system identifies vulnerable road sections based on historical disaster data stemming from heavy rains or typhoons on national roads. Continuous monitoring of these areas involves local rainfall data collection, enabling the activation of an early warning system when cumulative rainfall, measured by telemetering rain gauges, surpasses a predefined threshold. However, the existing standards of this system have proven inadequate in addressing the increased risk of landslide disasters resulting from recent climate change. Accumulated rainfall alone fails to address localized and intense rainfall events that occur within short timeframes. Furthermore, the system cancels precipitation accumulation when rainfall rates drop to 2 mm/hr or less for 3 h, disregarding factors like soil moisture and rainfall intensity. To address these limitations, this paper explores the incorporation of landslide alert information by the Japanese Meteorological Agency (JMA) into the advance traffic control system. The JMA's warnings, which consider both rainfall intensity and prior rainfall, align more closely with the mechanisms of slope hazards, providing a more robust approach to traffic regulation during extreme weather events. Additionally, the paper presents methods for improving the imbalance of data through numerical simulations. Ultimately, these advancements seek to modernize Japan's advance traffic control system to better address the evolving challenges presented by climate change and extreme weather conditions.