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 138 shops. At least one two-entranced, multi-seated public latrine overhung the bridge parapets and discharged into the river below; so did an unknown number of private latrines reserved for Bridge householders or shopkeepers and bridge officials. In 1382–83 a new latrine was made (or an old one replaced) at considerable cost, at the northern end of the bridge. The buildings on London Bridge were a major fire hazard and increased the load on its arches, several of which had to be rebuilt over the centuries. In 1212, perhaps the greatest of the early fires of London broke out on both