The Sangyo Bridge (신형산교) connects Pohang, South Korea to the Pohang Steel Corporation (now POSCO) via NR 31 over the Hyeongsan River.
Twin beam bridges, each carrying two lanes of traffic, was opened on November 28, 1967 to serve an upcoming industrial area for Pohang. A four-lane tied arch bridge was constructed from 1977-78 1 2 and a companion six-lane deck beam bridge was completed in 1995.2
The 1977-78 and 1995 structures received pier reinforcement and pavement rehabilitation in late 2015 at a cost of 1.7 billion ₩.1 2
A cycle-track and pedestrian bridge was later constructed adjacent to the 1995 structure.