Railways in Sydney on 9 December 1926 with the first suburban electric service running between Central station and Oatley on the Illawarra line. In the same year, the first underground railway was constructed north from Central station to St James in Sydney's central business district. Electric trains that had previously terminated at Central station continued north, diving underground at the Goulburn Street tunnel portal, stopping at Museum station and then terminating at St James. Other lines were soon electrified. Also, in conjunction with the construction of the Sydney Harbour Bridge which opened in 1932, an additional four-track underground line was constructed from Central
Sydney Harbour Bridge build a tunnel to complement the bridge. It was determined that the bridge could no longer support the increased traffic flow of the 1980s. The Sydney Harbour Tunnel was completed in August 1992 and carries only motor vehicles. The Bradfield Highway is designated as a Travelling Stock Route which means that it is permissible to herd livestock across the bridge, but only between midnight and dawn, and after giving notice of intention to do so. In practice, owing to the high-density urban nature of modern Sydney, and the relocation of abattoirs and markets, this has not taken place for approximately