mainline

adj

Normal, principal or standard. / (rail transport) Of or pertaining to the principal route or line of a railway.

The mainline road is busy during rush hour.

意味（1）

Normal, principal or standard.

意味（2）

(rail transport) Of or pertaining to the principal route or line of a railway.

意味（3）

(rail transport) Of or pertaining to a surface railway as distinct from an underground, elevated or light rail one.