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 composed for the occasion. The bridge itself was regarded as a triumph over Depression times, earning the nickname "the Iron Lung", as it kept many Depression-era workers employed. In 2010, the average daily traffic included 204 trains, 160,435 vehicles and 1650 bicycles. From the Sydney CBD side, motor vehicle access to the bridge is normally via Grosvenor Street, Clarence Street, Kent Street, the Cahill Expressway, or the Western Distributor. Drivers on the northern side will find themselves on the Warringah Freeway, though it is easy to turn off the freeway to drive westwards into North Sydney or eastwards to Neutral