However, the through operation was not realized due to the following reasons: Almost no passengers existed traveling through Tokyo station, the frequency of commercial power supplies were different from each other (60 Hz for the Tokai and Sanyo Shinkansen lines, and 50 Hz for the Tohoku, Joetsu and Nagano Shinkansen lines), and in addition, there were differences in the train-car designs, for example, measures against snow fall were taken for train-cars on the Tohoku and the Joetsu Shinkansen lines.
しかしながら、東京都を通過する需要がほとんどないという調査結果や、商用電源周波数の違い（東海道・山陽・九州新幹線は60Hzで、東北・上越・長野新幹線では50Hz）、それに東北・上越新幹線用のものには降雪対策が施されるなどといった車体設計の違いから、実現には至らなかった。