Humber Bridge July 1981. With a centre span of and a total length of , the Humber Bridge was the longest single-span suspension bridge in the world for 17 years, until Japan's Akashi Kaikyō Bridge opened on 5 April 1998. The road-distance between Hull and Grimsby was reduced by nearly as a consequence of the bridge. The bridge's surface takes the form of a dual carriageway with a lower-level foot and cyclepath on both sides. There is a permanent speed limit on the full length of the bridge. Each tower consists of a pair of hollow vertical concrete columns, each tall and
Underspanned suspension bridge heavy cross-braces. The only remaining underspanned Suspension bridge in the United States is the Kellams Bridge crossing the upper Delaware River between New York and Pennsylvania. Underspanned suspension bridge An underspanned suspension bridge (also upper deck suspension bridge) is a rare type of suspension bridge that was developed in the early 19th century. It differs from its ancestor, the simple suspension bridge, in that the deck is raised on posts above the main cables. The raised deck is less stable than a deck laid on or hung below the cables, and very few underspanned suspension bridges have been built. Examples