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
City of London east (downstream), cross the River Thames: Blackfriars Bridge, Blackfriars Railway Bridge, Millennium Bridge (footbridge), Southwark Bridge, Cannon Street Railway Bridge and London Bridge; Tower Bridge is not in the City. The City, like most of central London, is well served by buses, including night buses. Two bus stations are in the City, at Aldgate on the eastern boundary with Tower Hamlets, and at Liverpool Street by the railway station. There are approximately 28 Barclays Cycle Hire docking stations in the City. A number of existing and proposed cycle routes criss-cross the City, as part of the London Cycle Network. One