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.
The main roadway across the bridge is known as the Bradfield Highway and is about 2.4 km (1.5 mi) long, making it one of the shortest highways in Australia.
The arch has a span of 504 m (1,654 ft) and its summit is 134 m (440 ft) above mean sea level; however, expansion of the steel structure on hot days can increase the height of the arch by as much as 18 cm (7.1 in).
Large steel pins (or bearings) support each end of the arch, allowing it to rotate to accommodate expansion and contraction caused by changes of temperature, and avoiding stresses that would otherwise cause damage.
The bridge is nicknamed "The Coathanger" because of its arch-based design The southern (CBD) end of the bridge is located at Millers 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.
The pylons were not part of the original design, and were only added to allay public concern about the structural integrity of the bridge.
The stonemasons cut, dressed, and numbered the blocks, which were then transported to Sydney on three ships built specifically for this purpose.
The Moruya quarry was managed by John Gilmore, a Scottish stonemason who emigrated, with his young family to Australia in 1924, at the request of the project managers.
The total weight of the steelwork of the bridge, including the arch and approach spans, is 52,800 tonnes (52,000 long tons; 58,200 short tons), with the arch itself weighing 39,000 tonnes (38,000 long tons; 43,000 short tons).
The practice of riveting large steel structures, rather than welding, was, at the time, a proven and understood construction technique, whilst structural welding had not at that stage been adequately developed for use on the bridge.
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.