Out of Reach: New approaches to modelling low-SES access to destinations in Australian cities

Abstract

Access to essential goods and services is increasingly recognised as a key factor influencing household socio-economic vulnerability and disadvantage within cities. Socio-economic status and spatial location partly determine differential accessibility. Previously, the access made available to low socio-economic status (SES) groups via the transport system has been conceived subjectively, based on a collective perception of factors that contribute to a disadvantaged household. Further, spatial variation of these low-SES groups across cities, and their travel patterns, are mostly ignored by strategic transport models, which are concerned more with traffic volumes on the road network and peak hour travel. This paper summarises a promising method using cluster analysis techniques to identify low-SES groups on the Gold Coast directly from a large regional household travel survey. This allows for the identification of actual travel behaviour by key low-SES groups. Using this information, the paper then advances a new origin-destination-based land use and transport accessibility model. The model uses outputs from the cluster analysis, in conjunction with 2006 census data, to highlight differential accessibility to goods and service needs for a set of low-SES groups on the Gold Coast. The method being developed provides unique and significant opportunities for research into spatial disadvantage and accessibility in Australian cities. The use of freely available inputs, shrewd conceptualisation of the transport network, and outputs provided at the census collection district level, ensures the model may run concurrently with conventional strategic transport modelling. The method used and the results obtained have clear implications for transport infrastructure and service delivery planning.