This is the 4349th most frequent Japanese word.
区間
Section; segment; interval.
区間 refers to a segment or section of a larger entity, in this case, a railway.
この線路の一部区間は工事中です。
This segment of the railway is under construction.
区間 is used to describe the portion of a route being discussed, indicating changes made to specific areas of operation.
バスの運行区間が変更されました。
The operating routes of the bus have been changed.
区間 is being used to describe a specific segment or stretch within the entire marathon course.