Overview
- On Tuesday the Ministry of Land, Infrastructure, Transport and Tourism published a guideline that classifies underpass flooding risk into four levels and calls for remote‑operated barriers at the highest‑risk sites.
- Regional development bureaus in Kanto, Hokkaido and Tohoku began sending VICS and car‑navigation warnings tied to specific weather thresholds and have started publishing local risk lists, with Hokkaido naming 47 vulnerable underpasses.
- The national plan builds on an earlier decision to enable preemptive closures at 22 high‑risk national‑road underpasses but says staffing limits make manual shutdowns hard to sustain.
- Officials warn rollout will face practical hurdles including who manages each site across national, prefectural and municipal authorities, the cost and time to install remote barriers, and gaps in alert coverage across vehicle fleets.
- If implemented quickly the measures could cut drownings and limit road closures, but survivors and local road crews will feel changes first so watch for published local site lists and barrier installation timetables as the next signs of progress.