it facilitated the expansion of Auckland's built-up area in two ways: in an intermittent linear pattern to the west and south along the railway line, and in a more continuous manner along the main routes. The demand for more living space from people who had been confined to the crowded downtown area coupled with an affordable and reliable transport network led to the creation of many of Auckland's original suburbs, along Great North Road, New North Road, Sandringham Road, Dominion Road, Mt Eden Road, Manukau Road and Remuera Road, forming a new arc of suburban development by 1915. Auckland first railway, to Onehunga, opened in 1873. Expansion of the railway network facilitated growth in more distant locations such as Otahuhu and New Lynn, while ferries served Devonport, Takapuna and Birkenhead on the North Shore. Auckland's urban development in the early twentieth century is intrinsically linked to its transport networks, and because of their limited reach the city developed in a fairly compact manner to maximise the efficiency of the tram, railway and ferry systems. However, this situation was not to last for long, as even before the Second World War the car was becoming an integral part of life for many New Zealanders, opening up previously unreachable land for development. Late 20th century The number of cars in New Zealand skyrocketed from 69,521 in 1925 (when registration was first established) to 194,217 in 1938. This growing popularity meant that urban development could break free from the constraints of transport networks and occur anywhere roads were built. This led to a rapid decentralisation of urban growth, today often referred to as urban sprawl, in the 30 years after World War II. In an effort to compete with increasingly popular suburban shopping malls, parking lots and later parking buildings were built in the city centre. The first municipal parking building (Britomart Place) was completed in 1958. The tram system was dismantled in the 1950s and subsequent efforts to improve the rail network were not implemented. Meanwhile, a substantial motorway network was developed that facilitated urban growth to the north, northwest and south. These decisions led to Auckland becoming a highly car dependent city. Auckland Airport moved to its current site near Māngere in 1966, having been previously located in Whenuapai. 21st century Continued strong population growth, combined with cheaper car imports, led to growing traffic congestion across much of Auckland in the