(see map) however most of these lines remained concepts only and have never been constructed. The Depression and later World War II, along with the growth of the motor car that led to the passenger numbers in Bradfield's plans being grossly overestimated, all prevented the full realisation of the Bradfield scheme. Parts of the city underground were constructed and exist as the present day City Circle, with small sections built for the additional proposed city lines such as additional platforms at Wynyard and St James stations which have never been used for heavy rail transport. The underground city loop was constructed originally as a stub line to St James, and the line through Town Hall and Wynyard to the Harbour Bridge. It was not until 1955 that the loop was completed by the construction of Circular Quay station. A line to the eastern suburbs was eventually built, but along a different alignment to that envisaged by Bradfield, who proposed a line along Oxford Street. County of Cumberland Plan, 1948 This was the first comprehensive metropolitan landuse and transport plan for Sydney's existing and proposed future urban areas. Its sponsoring body, the Cumberland County Council, did not have the statutory powers to implement the plan, and much of the scheme was frustrated by uncontrolled development and policy decisions of other government bodies. One such element of the County of Cumberland planning scheme which did not see the light of day were two circumferential railways, one from the Cronulla line at Mortdale to the East Hills line at Riverwood, and to continue this route, another line from Padstow to the Bankstown line at Bankstown. By the early 1960s, large parts of these routes had been built on (much by another government body, the Housing Commission) and, without tunnelling, became unimplementable. Sydney Area Transportation Study, 1974 In 1968, the State Planning Authority of New South Wales released the Sydney Region Outline Plan, which was to guide the development of Sydney for the period 1970–2000. In particular, it aimed to develop new growth corridors to areas such as Green Valley, Campbelltown and Blacktown. This was followed in 1974 by the Sydney Area Transportation Study which proposed several new rail lines in the new growth areas as well as several new lines to ease congestion in the established areas of Sydney. The proposed lines were: a line linking Parramatta and Windsor via the Hills District,