This idea was proposed by a group of officials in the early 1990's, but it can be said that the possibility is very low because users would have to cross the runway (which in turn crosses over the Ina-gawa River) via a subway train and the line would have to make a big detour, and thus a huge construction expense would be required (while no realistic proposal about, for example, the construction force and financing has been made).
1990年代に入り一部筋から構想が持ち上がったが、猪名川を渡ったり滑走路を地下線で横断する必要があり大回りで建設費もかさむことから実現性の薄い構想といえる（建設主体や資金の手当てなどの現実的な案はない）。