However, eventually Osaka City constructed the fourth line using the third-rail system, whereupon Keihan abandoned the plan of constructing the new line and the remaining Kintetsu decided on a policy of introducing through-service between the new line by Kintetsu and the fourth line by developing train cars that use trolley lines on Kintetsu's line and also support the third-rail system; however, because Osaka City was reluctant to accept the plan, Kintetsu also abandoned the plan to construct the new line.
だが、結局大阪市が4号線を第三軌条式で建設してしまったため京阪は新線建設をあきらめ、残る近鉄が自社線内を架線式として架線式・第三軌条式両方に対応する車両を開発した上で4号線と相互直通する方針を固めたものの、大阪市が難色を示したため、近鉄も新線建設をあきらめるようになった。