Both lines, which run in the ancient capital, have suffered financial and time burdens because, prior to railroading, research on the buried cultural properties (archaeological sites) was required by the Cultural Assets Preservation Act at many of the sites where the company had decided to employ the open-cut method.
両線とも、古都と言う土地柄ゆえに、開削工法を採用した工区の多くで、文化財保護法によって工事着工前に埋蔵文化財（遺跡）の発掘調査が義務づけられ、そのための経費と期間が必要になった。