A somewhat formal or technical term for distance traveled, often used in contexts like transportation, surveying, or historical records. In everyday conversation, 距離 (きょり) is more common.
The distance markers on this road are shown in kilometers.
鉄道の里程を測る。
Measure the railway mileage.
milepost; milestone
Compound of 里 (ri, an old Japanese unit of distance) and 程 (extent, degree). Originally referred to distance measured in ri, later generalized to mileage or distance traveled.