 Further south, there is an extremely tight curve between Shimizu and Shimmori-Furuichi (at the Midori 1-chōme intersection), with a radius of ; this is the tightest curve on any Osaka subway line (excluding inter-line connections and depots).Trains must reduce speed to in this area.Because of these engineering difficulties, the expected 1/3 cost savings of employing smaller cross-section tunnels and linear motor trains did not emerge; instead, construction costs ballooned to ¥271.8 billion.