Maybe not common, but not an uncommon design. It is so you can transfer between lines by crossing the platform. https://en.wikipedia.org/wiki/Cross-platform_in

Maybe not common, but not an uncommon design. It is so you can transfer between lines by crossing the platform. https://en.wikipedia.org/wiki/Cross-platform_interchange https://en.wikipedia.org/wiki/Cross-platform_interchange https://www.youtube.com/watch?v=E5hXH_mLPzw https://www.youtube.com/watch?v=E5hXH_mLPzw