Kushiro road will close early before heavy rain

On September 4, 2026, a road office of Japan's transport ministry announced a new rule for a road in Kushiro. Kushiro is a city in Hokkaido, in the north of Japan. The office looks after national roads in the Kushiro area. It will now close the Asahi Underpass^*1 on Route 44 before heavy rain can flood^*2 it. The office will work with the police and other groups to do this.

The reason is a disaster in August 2026. Very heavy rain fell in Chiba, an area in Japan. An underpass there filled with water, and people were hurt. After this, the ministry decided it should not depend only on the drains^*3 that take water out of the underpass. It wants more than one way to keep people safe. Also, if the electricity stops or a machine breaks, the road should still move to the safe side and close. This idea is called "fail-safe^*4."

The office will close the road when any one of three things happens. First, when a Level 4 heavy rain warning is given. Second, when 40 millimeters^*5 of rain falls in one hour, or when that much rain is forecast^*6. Third, when the road office or the police think the underpass may flood.

The closed part of the road runs from the Asahicho 19 intersection^*7 to the Shin-Kushiro-cho 6 intersection. Both are in Kushiro.

The office also wants to stop cars from driving into the underpass when it is full of water. It is thinking about keeping "road closed" signs, barricades^*8 and traffic cones^*9 ready near the road. It is also thinking about gates that close by themselves, or that workers can close from far away.

1. *1 underpass: a road that goes under another road or a railway
2. *2 flood: to fill a place with water
3. *3 drains: pipes or holes that carry water away
4. *4 fail-safe: a way of building something so it stays safe even when a part stops working
5. *5 millimeters: a very small measure of length; 10 millimeters are 1 centimeter
6. *6 forecast: expected to happen, as told by the weather report
7. *7 intersection: a place where two roads cross
8. *8 barricades: fences or blocks put across a road to stop people or cars
9. *9 traffic cones: orange cone-shaped objects put on a road to show where cars must not go