bridge route

bridge route (plural bridge routes)

1. (rail transport, US) a railroad which provides a link from one major carrier (railroad) to another.
   • 1959, David P. Morgan, editor, Steam's Finest Hour, Kalmbach Publishing Co., page 34:

     A decade later D&H began buying fast, high-horsepower locomotives in the interest of lucrative bridge-route traffic.

• bridge line