相模川橋梁, Railway bridge in Samukawa and Hiratsuka, Kanagawa Prefecture, Japan

The Sagamigawa Bridge is a steel railway bridge on the Tokaido Shinkansen between Shin-Yokohama and Odawara, spanning the Sagami River on the boundary of Samukawa, Koza District, and Hiratsuka in Kanagawa Prefecture. It consists of six simple Warren through-truss spans; steel members join the tops of the trusses, so from a distance it looks like a continuous truss bridge. It carries double track.

The bridge opened on October 1, 1964, marking the start of Japan's high-speed rail system linking Tokyo with western regions. It became a critical part of the country's modernized transportation network during the post-war period.

The bridge's name is simply the Japanese for Sagami River Bridge, and it is known as the Sagamigawa Bridge on the Tokaido Shinkansen. Its six simple Warren trusses are joined by steel members along the top, so from a distance the crossing reads as one continuous truss bridge. The structure has carried Shinkansen trains since the line opened on 1 October 1964.

You can watch Shinkansen trains pass from Hiratsuka City Okami Sports Ground, which is reachable by bus from either Hiratsuka or Hon-Atsugi Station. The afternoon hours tend to offer more frequent train sightings for those interested in watching.

The steel trusses create an optical illusion where the structure appears as one connected piece rather than separate segments. This design choice adds both visual continuity and structural strength to the crossing.