Doctor Yellow; Shinkansen inspection train
A dedicated high-speed test train used to monitor track and overhead wire conditions on the Shinkansen network. The name is a wasei-eigo term derived from 'doctor' (diagnostic) and its yellow livery.
wasei-eigo (Japanese-coined English), from doctor yellow
It is said that seeing Doctor Yellow brings happiness.
Doctor Yellow measures track irregularities.
Wasei-eigo from English 'doctor' (diagnostic) and 'yellow' (its distinctive color).