From Spatial to Social Accessibility: How Socio-economic Factors Can Affect Accessibility?
MERCIER, Transport, Urban Planning and Economics Laboratory
The paper integers a social accessibility level to take into account individual inequalities and socio-economic disparities to access to urban opportunities. It analyses how gender and socio-professional categories affect travel time sensitivity.
Facing the challenges of “sustainable mobility paradigm” (Banister 2008), local transport policies should not only achieve economic growth and urban development in a sustainable point of view but they also have to satisfy the growing need for mobility. In this context, the concept of accessibility merits further use considering both spatial and social perspectives. If approach of “spatial accessibility” measurement refers to attractiveness of locations, it should be coupled to “social accessibility” index to take into account individual inequalities and socio-economic disparities to access to urban opportunities. Considering the Lyon metropolitan area in 2006, the objective of the paper is to highlight the interest to conduct a cross accessibility analysis from spatial to socio-spatial dimension.
The methodology is based on a “potential-gravity” based measure of accessibility to jobs combined to a transport model and a Geographical Information System. Spatial accessibility analysis is based on an aggregated location analysis under the hypothesis that socio-economic characteristics are the same for each individual. To surpass the weakness of the spatial approach social accessibility deals with desegregated travel cost and travel time sensitivity of different trip makers. Accessibility measurement depends therefore on individual location and socio-economic characteristics. This approach combining aggregated spatial accessibility and desegregated travel cost sensitivity weighted by population levels is applied to a new motorway combined with new dedicated lines for public transport.
The application underlines that females are less travel costs sensitive than males. Also, ssensitivity is lower the higher the social status is. Managers are ready to support the highest travel time costs while farmers are the most sensitive to travel time. Social accessibility results, linked to the population distribution according the socio-professional categories, highlights areas with a gap between perceived and offered accessibility level.
The paper presents the combined integration of socio-spatial dimensions into accessibility measure. It aims to improve “traditional” accessibility measures and to enlighten public decision makers in a public debate context. Nevertheless composite and complex accessibility indicators will integer all space-time dimensions but are not always easy to interpret for public decision makers who may prefer more simple indicators non subject to controversy into public meetings.
Association for European Transport