cab signal

plural cab signals

1. rail transportA device in the cab of a locomotive or train which displays the status of signals along the track.

   As we sped effortlessly along at a steady 75-80 m.p.h., with the three vertical lights of a clear aspect shining unwinkingly on the ground glass of the cab signal, our engineer lolled back in his chair and leisurely lit a huge cigar; [...].

   1961 June, J. Geoffrey Todd, “Impressions of railroading in the United States”, in Trains Illustrated, page 357