The idea of the parallel establishment of the Tozai Line and the Keihan Keishin Line was regarded as inappropriate, partly because it would result in excessive competition between these two lines and partly because the establishment of a subway line in a public subway system in this section for the Keihan Line would be the same as improving the Keihan Line, a private railway line, in a public system.
併設については、過当競争を招くとして、また、この区間の地下鉄を公営地下鉄方式で造り、そこに京阪線が乗り入れることは民営鉄道である京阪線の改良を公営方式で行うことになるために、不適当とされた。