Complex sentence: Two mini-shinkansen routes have been constructed: the Yamagata Shinkansen and Akita Shinkansen which traverse the Tohoku Shinkansen line from Tokyo before branching off to traditional main lines.
Split into simpler sentences: Two mini-shinkansen routes have been constructed: the Yamagata Shinkansen and Akita Shinkansen. Shinkansen services to these lines traverse the Tohoku Shinkansen line from Tokyo before branching off to traditional main lines.