REGIONAL GRAPHIC Mobility patterns in the Gauteng City-Region, South Africa

A key factor in understanding a city-region is the daily flows of people between its con- stituent parts. Traffic flows are often mapped to depict a 'commuter field', which may be taken as a delineation of a functional city-region (Manley, 2014; Organisation for Economic Co-operation and Development (OECD), 2011). Mapping of commuters' daily trips may graphically illustrate challenges with the efficiency, accessibility and affordability of a region's transport networks. Iterations of the same maps over time may reveal the impact of key transport interventions such as new connector roads or public transit operations. In addition, transport mapping may elucidate social dynamics, notably dimensions of everyday life and patterns of inequality between groups. We present two maps of the flows of trips to work across the Gauteng City-Region (GCR) in South Africa, one for 'whites' and the other for 'Africans' (see Figures 1 and 2). The maps are derived from the Gauteng City-Region Observatory's 2013 Quality of Life Survey. Run every two years, this representative household survey asks respondents - whose home location is captured with global positioning satellite (GPS) coordinates - to provide details of their most frequent trip, including the purpose, time taken and destination. A straight line plotting of movement from exact home origins to the centroid of destination suburbs has been done for each respondent who made a trip to work - 6741