Type 923 Doctor Yellow-T4 

Called the "Shinkansen Electric Track Comprehensive Test Vehicle", it is a vehicle that travels while inspecting the condition of track distortion, overhead line conditions, signal current conditions, etc. in the Shinkansen section.

The 923 type, which was developed based on the 700 series train from April 2001, is active at high speeds of 270km / h.

(As of April 2014)