noun
Refers to a physical transportation route: bus, train, air, etc. Used for both the path and the service designation.
この路線は朝の通勤時間帯に混雑する。
This line gets crowded during the morning rush hour.
新しいバス
A new bus route will open next month.
noun
Abstract use: the stance, policy, or direction taken by a group, organization, or individual. Often used in political, business, or editorial contexts.
政府は経済改革の路線を堅持している。
The government is sticking to its economic reform policy.
編集部は新しい路線を打ち出した。
The editorial department launched a new direction.