Day Trip to Shimonoseki - Stop over at Kanmonkyo Bridge Mekari Rest Area (SN.1670_2011)

The world's longest suspension bridges are listed according to the length of their main span (i.e. the length of suspended roadway between the bridge's towers). The length of main span is the most common method of comparing the sizes of suspension bridges, often correlating with the height of the towers and the engineering complexity involved in designing and constructing the bridge.

Suspension bridges have the longest spans of any type of bridge. Cable-stayed bridges, the next longest design, are practical for spans up to just over 1 km. Therefore the 15 longest bridges on this list are all currently the 15 longest spans of all types of vehicular bridges (other than floating pontoon bridges).

A suspension bridge is a type of bridge in which the deck (the load-bearing portion) is hung below suspension cables on vertical suspenders. Outside Tibet and Bhutan, where the first examples of this type of bridge were built in the 15th century, this type of bridge dates from the early 19th century. Bridges without vertical suspenders have a long history in many mountainous parts of the world.

This type of bridge has cables suspended between towers, plus vertical suspender cables that carry the weight of the deck below, upon which traffic crosses. This arrangement allows the deck to be level or to arc upward for additional clearance. Like other suspension bridge types, this type often is constructed without falsework.

The suspension cables must be anchored at each end of the bridge, since any load applied to the bridge is transformed into a tension in these main cables. The main cables continue beyond the pillars to deck-level supports, and further continue to connections with anchors in the ground. The roadway is supported by vertical suspender cables or rods, called hangers. In some circumstances the towers may sit on a bluff or canyon edge where the road may proceed directly to the main span, otherwise the bridge will usually have two smaller spans, running between either pair of pillars and the highway, which may be supported by suspender cables or may use a truss bridge to make this connection. In the latter case there will be very little arc in the outboard main cables.