The Sydney Harbour Bridge is a steel through arch bridge across Sydney Harbour that carries rail, vehicular, bicycle, and pedestrian traffic between the Sydney central business district (CBD) and the North Shore. The dramatic view of the bridge, the harbour, and the nearby Sydney Opera House is an iconic image of Sydney, and Australia. The bridge is nicknamed "The Coathanger" because of its arch-based design.Under the direction of Dr John Bradfield of the NSW Department of Public Works, the bridge was designed and built by British firm Dorman Long and Co Ltd of Middlesbrough and opened in 1932. The bridge's design was influenced by the Hell Gate Bridge in New York City. It is the sixth longest spanning-arch bridge in the world and the tallest steel arch bridge, measuring 134m from top to water level. It was also the world's widest long-span bridge, at 48.8m wide, until construction of the new Port Mann Bridge in Vancouver was completed in 2012.StructureThe southern end of the bridge is located at Dawes Point in The Rocks area, and the northern end at Milsons Point in the lower North Shore area. There are six original lanes of road traffic through the main roadway, plus an additional two lanes of road traffic on its eastern side, using lanes that were formerly tram tracks. Adjacent to the road traffic, a path for pedestrian use runs along the eastern side of the bridge, whilst a dedicated path for bicycle use only runs along the western side; between the main roadway and the western bicycle path are two lanes used for railway tracks, servicing the T1 North Shore Line for Sydney Trains.