Japan Railways (JR) — the group of passenger railway companies formed after the privatization of JNR; includes companies such as JR East.
毎朝、ＪＲで通勤しています。
I commute by JR every morning.
ＪＲの切符を駅の券売機で買った。
I bought a JR ticket at the station ticket machine.
旅行のときはＪＲの路線図をチェックしておくと便利だ。
It's useful to check the JR route map when traveling.