In January this year, a road collapse occurred in Yashio, Saitama Prefecture, north of Tokyo.

The male driver of a truck that fell into the sinkhole died.

To prevent such occurrences from happening, the land ministry has been conducting a survey of cavities beneath national highways across Japan.

In the examinations during last fiscal year through the end of March this year, the land ministry said it found cavities at 4,739 locations, with 119 of them having a high possibility of road collapse occurring.

Officials said work to fill the cavities in high-risk areas is underway and is scheduled to be completed by the end of August.

The survey covered about 3,000 kilometers, or about 15 percent, of all national routes in Japan.

The ministry will check the remaining national highways by the end of March 2029.