Strait of Messina Bridge have made the span more than 60% longer than the Akashi-Kaikyo Bridge in Japan—the largest suspension bridge in the world at . Plans called for four traffic lanes (two driving lanes and one emergency lane in each direction), two railway tracks and two pedestrian lanes. In order to provide a minimum vertical clearance for navigation of , the height of the two towers was to be . This would have been taller than the Millau Viaduct in France (currently the tallest bridge in the world at ). The bridge's suspension system would have relied on two pairs of steel cables,
Bridge four-lane highway on the upper level and a pair of railway tracks at the lower level. Tower Bridge in London is different example of a double-decked bridge, with the central section consisting of a low level bascule span and a high level footbridge. A viaduct is made up of multiple bridges connected into one longer structure. The longest and some of the highest bridges are viaducts, such as the Lake Pontchartrain Causeway and Millau Viaduct. A three-way bridge has three separate spans which meet near the center of the bridge. The bridge appears as a "T" or "Y" when viewed