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
London Bridge Is Falling Down popular culture. There is considerable variation in the lyrics of the rhyme. The most frequently used first verse is: <poem>London Bridge is falling down, Falling down, falling down. London Bridge is falling down, My fair lady.</poem> In the version quoted by Iona and Peter Opie in 1951 the first verse is: <poem>London Bridge is broken down, Broken down, broken down. London Bridge is broken down, My fair lady.</poem> The rhyme is constructed of quatrains in trochaic tetrameter catalectic, (each line made up of four metrical feet of two syllables, with the stress falling on the first syllable in a pair;