After that, following the Tokaido Shinkansen line, construction on the Sanyo Shinkansen line was started in 1967 in the form of extending the Tokaido Shinkansen line, to drastically increase transportation capacity of the Sanyo main line, transportation demands for which had also increased, as well as to increase the transportation speed on the line.
その後、東海道新幹線に続いて、同じように需要の増加していた山陽本線の抜本的輸送力改善と高速化を目的として、1967年に東海道新幹線を延伸する形で山陽新幹線が着工された。