the whole line; the entire route
Used for a single railway line, bus route, or similar transport line in its entirety.
台風のため、JR全線で運転を見合わせています。
Due to the typhoon, operations are suspended on all JR lines.
all lines; all routes
Refers to every line or route in a network, not just one.
このパスは地下鉄全線で使えます。
This pass can be used on all subway lines.
the whole front; all fronts
Military or figurative use for an entire battlefront or all areas of conflict. Also used metaphorically for a broad effort.
敵は全線で攻勢を強めた。
The enemy intensified their offensive on all fronts.
The Tokaido Shinkansen finally opened along its entire line.
Due to the typhoon, JR suspended operations on all its lines.
The fighting intensified along the entire front.