Using floating catchment analysis (FCA) techniques to examine intra-urban variations in accessibility to public transport opportunities: the example of Cardiff, Wales

Abstract: A relatively large literature base exists on the use of GIS to measure accessibility in transportstudies. Often such research efforts have been conducted as part of wider studies of social exclusion topublic transport opportunities. This paper aims to explore the use of floating catchment analysis (FCA)techniques to measure access to public transport opportunities. Whilst FCA methods have been used tomeasure access to health, employment and leisure services in particular, there have been few studiesfocused on their potential for measuring access to public transport services. This study builds onprevious research concerned with enhancing the FCA methodology to include aspects of proximity tobus stops, the balance between service supply and demand, and cumulative opportunity. We compareFCA-based access measures with both census-derived data and small area geodemographicclassifications in order to explore intra-urban variations in accessibility and potential associations withexisting socio-economic patterns. Our findings for the city of Cardiff, UK highlight no strongassociations with potential measures of social exclusion, and points to evidence that deprived areaswithin the city are actually better served in terms of the provision of public transport opportunitiesthan some affluent areas. These findings contrast with previous studies which have found disparitiesbetween transport supply and social needs. We suggest enhanced FCA measures have real potential instudies of transport-related social exclusion in identifying locations where services should be providedin relation to potential demand as well as in monitoring the implications of placing new routes andaccess points