Following World War Two, land use and transport policy and practice in most major Australian cities was modelled on the US experience. As such, these cities have become characterised by urban sprawl (indicated by segregated zoning and low development densities) and car dependence. In Perth, Western Australia, these characteristics are particularly evident despite, or perhaps because, the city has a strong regional planning system unlike most American cities. Car dependence and sprawl are in turn linked to dependence on fossil fuels for transport energy. Increasingly, too, links are being found between conventional planning outcomes and public health. For example, research has linked car dependence with a variety of health conditions including respiratory illness, overweight and obesity. Moreover, research is increasingly linking sprawl and car dependence with social justice issues because people on limited income and with decreased mobility struggle to undertake their life’s work. In response to these concerns the Western Australian planning system introduced Liveable Neighbourhoods, a new design code, which was meant to reduce car dependence and sprawl. This code has its roots in New Urbanism and appears to have been taken up more rapidly in Perth than elsewhere. No large-scale evaluation of New Urbanism has previously been conducted anywhere. This thesis reports on an extensive literature review, travel survey (n=211), perceptual study (n=992) and environmental study, which together sought to evaluate whether the Liveable Neighbourhoods (LN) design code is contributing to a sustainable transport agenda. In total, 46 neighbourhoods (11 LNs and 35 CNs) were compared. The research found that despite residents of Liveable Neighbourhoods driving less and walking more than residents of conventional neighbourhoods (CNs) (a switch of 9% with some associated health advantages), there was little else to indicate that LN is achieving its goals as transport VKT and fuel use was identical due to regional transport requirements diminishing any local walkability advantages. There was strong supportive evidence that LNs were not significantly different to CNs. For example, there were few differences in perception of opportunity for more sustainable travel and residents of CNs actually had better access, on average, to key destinations, including shops (i.e. the average distance to key destinations was 2.2 kilometres compared with 2.5 kilometres in LNs). Also, residential lot densities were well below what were intended by LN and in both LNs and CNs the time for public transport to get people to work was over 90 minutes compared with around 30 minutes by car. The results reveal that there must be significant revisions to the LN code and how it is applied, because there is no evidence that new neighbourhoods are improving regional transport sustainability. In particular, residential densities and land use mix appear to be too low to encourage community self-sufficiency, indicated by few neighbourhoods being anchored by key destinations. These matters are not mandated in the LN guidelines making them powerless to bring significant change. More generally, the thesis questions the extent to which New Urbanism can promote a sustainable transport agenda wherever it is applied unless it mandates real changes in land use and transit not just local walkability.