The 31st Street Bridge, is an arch bridge that carries vehicular traffic across the Allegheny River between the Pittsburgh neighborhoods of Troy Hill and the Strip District. The bridge passes over, but does not serve, Herrs Island, which is connected to the mainland by the 30th Street Bridge. Sidewalks along the bridge feature viewing platforms. The bridge was built in 1927–1928 to replace an earlier through truss bridge aligned with 30th Street. This earlier bridge was built in 1887 but was destroyed by fire on July 8, 1921.
The 1887 bridge itself replaced a two span iron truss which was destroyed by a flood in 1882. A cable suspension footbridge was provided as a crossing whilst the new 31st Street bridge was being constructed. The bridge was due to close on Tuesday January 31, 2006 for a proposed $27 million refurbishment which would take two years. It eventually closed on February 14, 2006 and reopened by Mayor Luke Ravenstahl on November 21, 2007.