Hitsuishijima Bridge, Cable-stayed bridge in Seto Inland Sea, Japan

Hitsuishijima Bridge is a 792 m steel truss cable-stayed bridge between Hitsuishijima and Iwakurojima islands, with a 420 m main span and towers 148 m and 152 m tall. Its two decks carry the Seto-Chuo Expressway above and the JR Honshi-Bisan Line below. The piers widen toward the deck and narrow above it, a shape based on a helmet or shrine roof.

Construction of the Hitsuishijima Bridge began in 1978 and the structure was completed in 1988, the year it opened as part of the Seto-Chuo Expressway. The original plan, shared with the neighbouring Iwakurojima Bridge, was a birdcage-like truss; concern for the scenery of the Seto Inland Sea led to the switch to a cable-stayed design. Its three spans measure 185, 420 and 185 metres.

The bridge links two distinct regions, making it easier for people to move between Okayama and Kagawa for work and daily life. Communities on either side have maintained their own traditions while increasingly sharing influences through this constant flow of connection.

Visitors can cross the bridge by car on the Seto-Chuo Expressway, though a toll applies. Walking is not permitted, but several viewpoints nearby offer good views of the structure from a distance.

This was one of Japan's first attempts to successfully combine two entirely different transportation modes on a single structure. The design approach proved so effective that it became a template for similar projects elsewhere in the country.