【国土交通省北海道開発局】有珠山噴火災害に伴う国道230号復旧工事記録

Mount Usu has recorded four eruptions, roughly every 20 to 30 years, from the Meiji era through the Showa and Heisei eras. Thanks to the volcano's bounty, the Toyako Hot Springs area at its base is a popular destination for both domestic and international tourists every year. Following the 2000 eruption, the area was designated a Global Geopark in 2009, fueling a surge in local activity. The March 31, 2000, eruption created a crater on National Route 230, causing stepped crustal deformation and rendering the highway impassable. The damaged Route 230, the shortest route between Sapporo and Hakodate, served as Hokkaido's main artery and was heavily used by many people. While a parallel local road was upgraded to a national highway immediately after the disaster, securing a transportation network connecting central and southern Hokkaido, a new route was urgently needed. The new route was planned to have two tunnels, approximately 80% of its 4.6-kilometer length, in order to ensure a safe route even in the event of another eruption. It was opened to traffic on March 28, 2008 (Heisei 19), five years after construction began. Here we introduce a video that compiles records of the new route's investigation and planning immediately after the eruption in 2000 (Heisei 12), from the start of construction to its completion. [Produced in 2007]