However, concerning the Shinkansen lines, the prospect of realizing a through operation is considered small for the following reason in addition to the reasons described above: Each Shinkansen line is operated by a separate company, in contrast to the era of Japan National Railways (JR Tokai has decided that 16-car trains must be used for a through operation).
しかしながら、新幹線については前述の理由に加え、国鉄時代と違い別会社の運行となっており、実現の可能性は低いと見られている（JR東海側の意向により、16両貫通の編成で無い限りは同社の路線への乗り入れは不可となっている。