D defs.my
Entry 1 sense Webster, 1913

Traffic mile

· Traf·fic mile · IPA
01 Any unit of the total obtained by adding the passenger miles and ton miles in a railroad's transportation for a given period; -- a term and…
  1. 1.
    Any unit of the total obtained by adding the passenger miles and ton miles in a railroad's transportation for a given period; -- a term and practice of restricted or erroneous usage.(Railroad Accounting)
    Traffic mile is a term designed to furnish an excuse for the erroneous practice of adding together two things (ton miles and passenger miles) which, being of different kinds, cannot properly be added.” — Hadley.