[bobthepanda]

The original lines may be from the private era but JNR also built a lot.

The Saikyo, Keiyo, and Musashino Lines in Tokyo were all built by JNR. So was all the Shinkansen. And all the main lines around Tokyo were quadrupled or sextupled by JNR at great cost. And let’s not forget the feats of the Kanmon tunnel to Kyushu, the Seikan tunnel to Hokkaido, and the Great Seto Bridge to Shikoku.

Tokyo Metro and Toei are also state-owned, and private operators directly benefit from the through operations into the Yamanote loop.