But the mid-'60s was also the heyday of interstate highway construction and truss bridges still had the advantages they had since railroad pioneers made them out of wood: they are relatively cheap ...

The strengths and weaknesses of two large wooden bridge trusses, reconstructed from a 1918 bridge that was destroyed by arson, are being studied at Case Western Reserve University.

The second-longest continuous truss bridge. The Francis Scott Key Bridge was the second-longest continuous truss bridge span in the world, according to the American Civil Engineering Society.

At top, the bridge on the River Kwai as it was before bombs were dropped on it in February 1945. At bottom, two collapsed spans of the bridge lay in the river.