**Progress in Aging Social Infrastructure and Countermeasures**.

**Progress in Aging Social Infrastructure and Countermeasures**.

Many of Japan's social infrastructures were constructed between the 1950s and 1970s and are aging. The Ministry of Land, Infrastructure, Transport and Tourism is promoting the "Longevity Repair Plan" because 150,000 road bridges across Japan are noticeably aging. 2020's will see large-scale seismic reinforcement and renewal work underway at Tokyo Metropolitan Expressway and bridges in Osaka Prefecture. In Hiroshima Prefecture, about 30% of bridges have exceeded their useful life, and inspection and repair are prioritized. New materials such as Sumitomo Chemical's high-performance concrete and Toray's carbon fiber are being introduced, and Kajima Corporation's AI inspection technology is also being used. Preventive maintenance is expected to significantly reduce maintenance costs, and sustainable infrastructure maintenance is being promoted through collaboration between local governments and companies.