Japan writes new guidelines for flooded underpasses

An underpass^*1 is a road that goes under another road or a railway. When it rains very hard, water can fill the low part of an underpass. Cars drive in, and they get stuck in the water.

This has happened many times in Japan this year. In August 2026, very heavy rain fell in Chiba, an area in Japan. In that storm and other big rains, underpasses filled with water. People were hurt, and cars and other things were damaged.

Japan's Ministry of Land, Infrastructure, Transport and Tourism looks after the country's roads. On October 6, its road office published new guidelines^*2 to stop these accidents.

The guidelines ask for several kinds of protection at the same time. First, roads should close before the water comes, or quickly when the water starts to rise. Second, there should be ways to stop cars from entering a flooded underpass. Third, the water must be able to drain^*3 away. The guidelines also say that when something goes wrong, the system must always choose the safe way.

The ministry has a short slogan^*4 for the plan: "Stop before it floods, and don't let them in."

1. *1 underpass: a road that goes under another road or a railway
2. *2 guidelines: written rules that tell people the right way to do something
3. *3 drain: to flow away through pipes or holes
4. *4 slogan: a short, easy sentence that people remember