trolley line

from WordNet (r) 3.0 (2006)

trolley line
    n 1: a transit line using streetcars or trolley buses

from The Collaborative International Dictionary of English v.0.48

Trolley car \Trol"ley car\ (Elec.)
   A motor car powered by electricity drawn from a trolley, and
   thus constrained to follow the trolley lines.
   [Webster 1913 Suppl. +PJC]

   {Trolley line},
   (a) A trolley
   (f) .
   (b) The path along which a trolley car runs.
       [PJC]